Communication method and related device

Abstract

The invention discloses a communication method and a related device, and the method comprises the steps: determining a synchronization signal, and transmitting the synchronization signal to a label on a first time domain resource and a first frequency domain resource. The first time domain resource comprises M orthogonal frequency division multiplexing (OFDM) symbols, the first frequency domain resource comprises N * 12 subcarriers, and both M and N are positive integers. Wherein the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal comprises a first signal and a second signal, the first signal indicates that the second signal is behind the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of T1 and T2 is equal to the duration of M OFDM symbols. According to the invention, the method can be compatible with the design of a synchronization signal of a label (namely a passive label or a semi-passive label) under different downlink signal bandwidths, and facilitates the improvement of the communication performance.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method and related devices. Background Art

[0002] With the increasing application of the fifth generation (5th generation mobile communication technology, 5G) new radio (NR) machine-type communication (mMTC) and Internet of things (IoT) communication, the number of IoT device connections is increasing day by day. Considering the issues of reducing the cost and power consumption of IoT devices, the 3rd generation partnership project (3GPP) proposed passive IoT communication technology in the 5GNR system to meet the requirements of IoT application cost and low power consumption.

[0003] In a passive IoT system, the reader sends a high-level waveform to a passive tag, which receives the energy and reflects the information to the reader through a reverse link. Currently, readers mainly use pulse interval encoding (PIE) to send synchronization signals, and the design of the synchronization signal only considers the case when the downlink signal bandwidth is 12 subcarriers, so it is not compatible with a wider downlink signal bandwidth. Summary of the invention

[0004] The present application provides a communication method and related devices, which are compatible with the design of synchronization signals for passive tags under different downlink signal bandwidths, and are conducive to improving communication performance.

[0005] In a first aspect, the present application provides a communication method. Optionally, the execution subject of the method may be a network device, or a component or device (such as a processor, a chip, or a chip system, etc.) applied to the network device, or a logic module or software that can implement all or part of the network device functions. The method includes:

[0006] determining a synchronization signal;

[0007] Sending the synchronization signal on a first time domain resource and a first frequency domain resource, where the first time domain resource includes M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where both M and N are positive integers;

[0008] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of the T1 and the T2 is equal to the duration of the M OFDM symbols.

[0009] In the present application, the synchronization signal is a signal sent by a network device to a passive tag or a semi-passive tag, wherein the synchronization signal may also be referred to as a synchronization signal of a passive tag, or a leading signal, or a leading signal of a data signal, or a leading signal of a passive tag, or a leading signal of a passive tag data signal, etc. These names are only examples, and other names may be used in specific implementations, and the present application does not make specific limitations on this. It should be noted that the present application is different from the current design of the synchronization signal, which only considers the design when the downlink signal bandwidth is 12 subcarriers. The present application is compatible with the design of synchronization signals for passive tags under different downlink signal bandwidths, which increases the flexibility of downlink transmission and is conducive to improving communication performance. At the same time, under different bandwidths, the duration T1 of the first signal is fixed, which is conducive to meeting the requirements for the duration of the passive tag delimiter, and the duration T2 of the second signal is fixed, which is conducive to clock detection.

[0010] In a possible design, any level included in the first signal is a first level.

[0011] In this implementation, the first level can be understood as a low level or an OOK symbol {0} or an OOK chip {0}. The first signal is a full low level signal, so that the first signal can enable the receiving circuit to have sufficient buffer time before receiving the second signal and the data signal, and try to avoid confusion between the first signal and the subsequent second signal and the data signal, which is conducive to improving the demodulation performance.

[0012] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0013] In this implementation, the second level can be understood as a high level or an OOK symbol {1} ​​or an OOK chip {1}. The number of first levels included in the second signal is equal to the number of second levels, and the duration of the second level is equal to the duration of the first level, so that the design of the synchronization signal including the second signal can meet the level time detection of subsequent data using Manchester coding, wherein Manchester coding is conducive to improving the communication performance of data transmission.

[0014] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0015] In this implementation, the second signal may specifically be a signal in which {0} and {1} levels appear alternately, and the number of {0} and {1} is equal, for example, the second signal may be {010101}. Alternatively, the second signal may also be a signal in which {1} and {0} levels appear alternately, and the number of {0} and {1} is equal, for example, the second signal may be {101010}. The design method of the signal sequence in which different levels appear alternately is relatively simple, and the rising edge and the falling edge appear periodically, which is conducive to reducing the detection complexity of the unit level time and can ensure the detection performance.

[0016] In one possible design, the duration of one OFDM symbol is T;

[0017] The duration T1 of the first signal satisfies:

[0018] T1 = M*T*X;

[0019] The duration T2 of the second signal satisfies:

[0020] T2 = M*T*(1-X);

[0021] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0022] In this implementation, the duration T1 of the first signal and the duration T2 of the second signal satisfying the above formula can adapt to the adaptive design of the fixed time of the first signal and the fixed time of the second signal under different signal bandwidths. In addition, when M=1, the value of X is associated with the subcarrier spacing, which can meet the requirements of the duration of the passive tag delimiter under different subcarrier spacings.

[0023] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N, and the number P2 of levels included in the second signal is proportional to the value of N.

[0024] In this implementation, the number P1 of levels included in the first signal and the number P2 of levels included in the second signal are proportional to the value of N, which can adapt to the design of the first signal under different signal bandwidths and improve the applicability of the solution.

[0025] In one possible design, the number P1 of levels included in the first signal satisfies:

[0026] P1 = M*K*N*X;

[0027] The number P2 of levels included in the second signal satisfies:

[0028] P2=M*K*N*(1-X);

[0029] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0030] In this implementation, the number of levels satisfying the above formula can meet the requirements of the number of rising edges and falling edges of the time calibration level, thereby ensuring the performance of time detection.

[0031] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0032] In this implementation, the number of levels included in the second signal is ≥2 or 4 (preferred), which ensures the number of levels that can be used when the tag performs clock calibration and is conducive to improving the accuracy of obtaining level boundaries (symbol boundaries) during detection.

[0033] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0034] In this implementation, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2, which can effectively ensure the buffer time for data reception when the tag is started (that is, when X is 1 / 3 or 1 / 2, under different bandwidths, the duration of the first signal is not shorter than the prescribed duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs)).

[0035] In a second aspect, the present application provides a communication method. Optionally, the execution subject of the method may be a network device, or a component or device (such as a processor, a chip, or a chip system, etc.) applied to the network device, or a logic module or software that can implement all or part of the network device functions. The method includes:

[0036] determining a synchronization signal;

[0037] Sending the synchronization signal on a first time domain resource and a first frequency domain resource, the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers;

[0038] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

[0039] In the present application, the synchronization signal is a signal sent by a network device to a passive tag or a semi-passive tag. Different from the current design of the synchronization signal, which only considers the design when the downlink signal bandwidth is 12 subcarriers, the present application is compatible with the design of the synchronization signal for passive tags under different downlink signal bandwidths, which is conducive to improving communication performance. At the same time, under different bandwidths, keeping the duration T1 of the first signal fixed is conducive to meeting the requirements of the duration of the passive tag delimiter, and keeping the number of levels P2 included in the second signal unchanged, which can effectively ensure the number of levels that can be used when the tag performs clock calibration, and improve the peak rate of downlink transmission.

[0040] In a possible design, any level included in the first signal is a first level.

[0041] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0042] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0043] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0044] In this implementation, the duration T2 of the second signal is inversely proportional to the value of N, which is an adaptive design for the fixed time of the first signal and the fixed number of levels of the second signal. This is conducive to enhancing the flexibility of downlink transmission under different bandwidths and improving the transmission peak rate.

[0045] In one possible design, the duration of one OFDM symbol is T;

[0046] The duration T1 of the first signal satisfies:

[0047] T1 = M*T*X;

[0048] The duration T2 of the second signal satisfies:

[0049] T2=M*T*(1-X) / N;

[0050] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0051] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N.

[0052] In one possible design, the number P1 of levels included in the first signal satisfies:

[0053] P1 = M*K*N*X;

[0054] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0055] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0056] In this implementation, the number of levels included in the second signal is ≥2 or 4 (preferred), which ensures the number of levels that can be used when the tag performs clock calibration and is conducive to improving the accuracy of obtaining level boundaries (symbol boundaries) during detection.

[0057] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0058] In this implementation, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2, which can effectively ensure the buffer time for data reception when the tag is started (that is, when X is 1 / 3 or 1 / 2, under different bandwidths, the duration of the first signal is not shorter than the prescribed duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs)).

[0059] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0060] The duration T3 of the third signal satisfies:

[0061] T3 = M*T - T1 - T2;

[0062] The number P3 of levels included in the third signal satisfies:

[0063] P3 = M*K*N - P1 - P2;

[0064] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0065] In this implementation, the introduction of the third signal enables the tag to obtain more energy, which is beneficial to maintaining normal communication.

[0066] In one possible design, P2 is equal to 4.

[0067] In this implementation, the number of levels included in the second signal is fixed to 4, which can ensure the number of levels that can be used when the tag performs clock calibration. In addition, the transmission peak rate of the tag is maximized as much as possible.

[0068] In a third aspect, the present application provides a communication method. Optionally, the execution subject of the method may be a network device, or a component or device (such as a processor, a chip, or a chip system, etc.) applied to the network device, or a logic module or software that can implement all or part of the network device functions. The method includes:

[0069] determining a synchronization signal;

[0070] Sending the synchronization signal on a first time domain resource and a first frequency domain resource, the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, the first frequency domain resource includes N×12 subcarriers, and both M and N are positive integers;

[0071] Among them, the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, and the number P2 of levels included in the second signal is a fixed value.

[0072] In the present application, the synchronization signal is a signal sent by a network device to a passive tag or a semi-passive tag. Different from the current design of the synchronization signal, which only considers the design when the downlink signal bandwidth is 12 subcarriers, the present application is compatible with the design of the synchronization signal for passive tags under different downlink signal bandwidths, which is beneficial to improving communication performance. At the same time, under different bandwidths, the sum of the duration T1 of the first signal and the duration of the first level in the second signal is fixed, which is beneficial to meeting the requirements of the duration of the passive tag delimiter, and the duration T2 of the second signal is fixed, which is beneficial to clock detection.

[0073] In a possible design, any level included in the first signal is a first level.

[0074] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0075] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0076] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0077] In this implementation, the duration T2 of the second signal is inversely proportional to the value of N, which is an adaptive design that keeps the time of the first level of the first signal + the second signal fixed and the number of fixed levels of the second signal. This is conducive to enhancing the flexibility of downlink transmission under different bandwidths and improving the transmission peak rate.

[0078] In one possible design, the duration of one OFDM symbol is T;

[0079] The duration T1 of the first signal satisfies:

[0080] T1=M*T*X-M*T / K*N;

[0081] The duration T2 of the second signal satisfies:

[0082] T2=M*T*(1-X) / N;

[0083] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0084] In a possible design, the sum of the number P1 of levels included in the first signal and 1 is proportional to the value of N.

[0085] In one possible design, the number P1 of levels included in the first signal satisfies:

[0086] P1=M*K*N*X-1;

[0087] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0088] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0089] In this implementation, the number of levels included in the second signal is ≥2 or 4 (preferred), which ensures the number of levels that can be used when the tag performs clock calibration and is conducive to improving the accuracy of obtaining level boundaries (symbol boundaries) during detection.

[0090] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0091] In this implementation, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2, which can effectively ensure the buffer time for data reception when the tag is started (that is, when X is 1 / 3 or 1 / 2, under different bandwidths, the duration of the first signal is not shorter than the prescribed duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs)).

[0092] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0093] The duration T3 of the third signal satisfies:

[0094] T3 = M*T - T1 - T2;

[0095] The number P3 of levels included in the third signal satisfies:

[0096] P3 = M*K*N - P1 - P2;

[0097] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0098] In this implementation, the introduction of the third signal enables the tag to obtain more energy, which is beneficial to maintaining normal communication.

[0099] In one possible design, P2 is equal to 4.

[0100] In this implementation, the number of levels included in the second signal is fixed to 4, which can ensure the number of levels that can be used when the tag performs clock calibration. In addition, the transmission peak rate of the tag is maximized as much as possible.

[0101] In a fourth aspect, the present application provides a communication method. Optionally, the execution subject of the method may be a tag, or a component or device applied to the tag (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can realize all or part of the tag function. The tag may be a passive tag or a semi-passive tag. The method includes:

[0102] Receiving a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the first time domain resource includes M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where both M and N are positive integers;

[0103] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of T1 and T2 is equal to the duration of the M OFDM symbols.

[0104] In a possible design, any level included in the first signal is a first level.

[0105] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0106] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0107] In one possible design, the duration of one OFDM symbol is T;

[0108] The duration T1 of the first signal satisfies:

[0109] T1 = M*T*X;

[0110] The duration T2 of the second signal satisfies:

[0111] T2 = M*T*(1-X);

[0112] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0113] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N, and the number P2 of levels included in the second signal is proportional to the value of N.

[0114] In one possible design, the number P1 of levels included in the first signal satisfies:

[0115] P1 = M*K*N*X;

[0116] The number P2 of levels included in the second signal satisfies:

[0117] P2=M*K*N*(1-X);

[0118] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0119] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0120] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0121] In a fifth aspect, the present application provides a communication method. Optionally, the execution subject of the method may be a tag, or a component or device applied to the tag (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can realize all or part of the tag function. The tag may be a passive tag or a semi-passive tag. The method includes:

[0122] Receiving a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers;

[0123] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

[0124] In a possible design, any level included in the first signal is a first level.

[0125] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0126] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0127] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0128] In one possible design, the duration of one OFDM symbol is T;

[0129] The duration T1 of the first signal satisfies:

[0130] T1 = M*T*X;

[0131] The duration T2 of the second signal satisfies:

[0132] T2=M*T*(1-X) / N;

[0133] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0134] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N.

[0135] In one possible design, the number P1 of levels included in the first signal satisfies:

[0136] P1 = M*K*N*X;

[0137] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0138] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0139] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0140] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0141] The duration T3 of the third signal satisfies:

[0142] T3 = M*T - T1 - T2;

[0143] The number P3 of levels included in the third signal satisfies:

[0144] P3 = M*K*N - P1 - P2;

[0145] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0146] In one possible design, P2 is equal to 4.

[0147] In a sixth aspect, the present application provides a communication method. Optionally, the execution subject of the method may be a tag, or a component or device applied to the tag (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can realize all or part of the tag function. The tag may be a passive tag or a semi-passive tag. The method includes:

[0148] Receiving a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, the first frequency domain resource includes N×12 subcarriers, and both M and N are positive integers;

[0149] Among them, the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, and the number P2 of levels included in the second signal is a fixed value.

[0150] In a possible design, any level included in the first signal is a first level.

[0151] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0152] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0153] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0154] In one possible design, the duration of one OFDM symbol is T;

[0155] The duration T1 of the first signal satisfies:

[0156] T1=M*T*X-M*T / K*N;

[0157] The duration T2 of the second signal satisfies:

[0158] T2=M*T*(1-X) / N;

[0159] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0160] In a possible design, the sum of the number P1 of levels included in the first signal and 1 is proportional to the value of N.

[0161] In one possible design, the number P1 of levels included in the first signal satisfies:

[0162] P1=M*K*N*X-1;

[0163] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0164] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0165] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0166] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0167] The duration T3 of the third signal satisfies:

[0168] T3 = M*T - T1 - T2;

[0169] The number P3 of levels included in the third signal satisfies:

[0170] P3 = M*K*N - P1 - P2;

[0171] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer. In a possible design, P2 is equal to 4.

[0172] In a seventh aspect, the present application provides a communication device, which may be a network device or a module or chip in a network device. The communication device includes:

[0173] A processing unit, configured to determine a synchronization signal;

[0174] A transceiver unit, configured to send the synchronization signal on a first time domain resource and a first frequency domain resource, wherein the first time domain resource includes M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where both M and N are positive integers;

[0175] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of the T1 and the T2 is equal to the duration of the M OFDM symbols.

[0176] In a possible design, any level included in the first signal is a first level.

[0177] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0178] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0179] In one possible design, the duration of one OFDM symbol is T;

[0180] The duration T1 of the first signal satisfies:

[0181] T1 = M*T*X;

[0182] The duration T2 of the second signal satisfies:

[0183] T2 = M*T*(1-X);

[0184] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0185] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N, and the number P2 of levels included in the second signal is proportional to the value of N.

[0186] In one possible design, the number P1 of levels included in the first signal satisfies:

[0187] P1 = M*K*N*X;

[0188] The number P2 of levels included in the second signal satisfies:

[0189] P2=M*K*N*(1-X);

[0190] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0191] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0192] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0193] In an eighth aspect, the present application provides a communication device, which may be a network device or a module or chip in a network device. The communication device includes:

[0194] A processing unit, configured to determine a synchronization signal;

[0195] A transceiver unit, configured to send the synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers;

[0196] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

[0197] In a possible design, any level included in the first signal is a first level.

[0198] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0199] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0200] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0201] In one possible design, the duration of one OFDM symbol is T;

[0202] The duration T1 of the first signal satisfies:

[0203] T1 = M*T*X;

[0204] The duration T2 of the second signal satisfies:

[0205] T2=M*T*(1-X) / N;

[0206] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0207] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N.

[0208] In one possible design, the number P1 of levels included in the first signal satisfies:

[0209] P1 = M*K*N*X;

[0210] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0211] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0212] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0213] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0214] The duration T3 of the third signal satisfies:

[0215] T3 = M*T - T1 - T2;

[0216] The number P3 of levels included in the third signal satisfies:

[0217] P3 = M*K*N - P1 - P2;

[0218] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0219] In one possible design, P2 is equal to 4.

[0220] In a ninth aspect, the present application provides a communication device, which may be a network device or a module or chip in a network device. The communication device includes:

[0221] A processing unit, configured to determine a synchronization signal;

[0222] A transceiver unit, configured to send the synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N×12 subcarriers, and both M and N are positive integers;

[0223] Among them, the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, and the number P2 of levels included in the second signal is a fixed value.

[0224] In a possible design, any level included in the first signal is a first level.

[0225] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0226] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0227] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0228] In one possible design, the duration of one OFDM symbol is T;

[0229] The duration T1 of the first signal satisfies:

[0230] T1=M*T*X-M*T / K*N;

[0231] The duration T2 of the second signal satisfies:

[0232] T2=M*T*(1-X) / N;

[0233] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0234] In a possible design, the sum of the number P1 of levels included in the first signal and 1 is proportional to the value of N.

[0235] In one possible design, the number P1 of levels included in the first signal satisfies:

[0236] P1=M*K*N*X-1;

[0237] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0238] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0239] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0240] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0241] The duration T3 of the third signal satisfies:

[0242] T3 = M*T - T1 - T2;

[0243] The number P3 of levels included in the third signal satisfies:

[0244] P3 = M*K*N - P1 - P2;

[0245] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0246] In one possible design, P2 is equal to 4.

[0247] In a tenth aspect, the present application provides a communication device, which may be a tag or a module or chip in a tag. The tag may be a passive tag or a semi-passive tag. The communication device includes:

[0248] A transceiver unit, configured to receive a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the first time domain resource includes M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where both M and N are positive integers;

[0249] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of the T1 and the T2 is equal to the duration of the M OFDM symbols.

[0250] In a possible design, any level included in the first signal is a first level.

[0251] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0252] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0253] In one possible design, the duration of one OFDM symbol is T;

[0254] The duration T1 of the first signal satisfies:

[0255] T1 = M*T*X;

[0256] The duration T2 of the second signal satisfies:

[0257] T2 = M*T*(1-X);

[0258] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0259] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N, and the number P2 of levels included in the second signal is proportional to the value of N.

[0260] In one possible design, the number P1 of levels included in the first signal satisfies:

[0261] P1 = M*K*N*X;

[0262] The number P2 of levels included in the second signal satisfies:

[0263] P2=M*K*N*(1-X);

[0264] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0265] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0266] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0267] In an eleventh aspect, the present application provides a communication device, which may be a tag or a module or chip in a tag. The tag may be a passive tag or a semi-passive tag. The communication device includes:

[0268] A transceiver unit, configured to receive a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers;

[0269] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

[0270] In a possible design, any level included in the first signal is a first level.

[0271] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0272] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0273] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0274] In one possible design, the duration of one OFDM symbol is T;

[0275] The duration T1 of the first signal satisfies:

[0276] T1 = M*T*X;

[0277] The duration T2 of the second signal satisfies:

[0278] T2=M*T*(1-X) / N;

[0279] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0280] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N.

[0281] In one possible design, the number P1 of levels included in the first signal satisfies:

[0282] P1 = M*K*N*X;

[0283] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0284] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0285] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0286] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0287] The duration T3 of the third signal satisfies:

[0288] T3 = M*T - T1 - T2;

[0289] The number P3 of levels included in the third signal satisfies:

[0290] P3 = M*K*N - P1 - P2;

[0291] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0292] In one possible design, P2 is equal to 4.

[0293] In a twelfth aspect, the present application provides a communication device, which may be a tag or a module or chip in a tag. The tag may be a passive tag or a semi-passive tag. The communication device includes:

[0294] A transceiver unit, configured to receive a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N×12 subcarriers, and both M and N are positive integers;

[0295] Among them, the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, and the number P2 of levels included in the second signal is a fixed value.

[0296] In a possible design, any level included in the first signal is a first level.

[0297] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0298] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0299] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0300] In one possible design, the duration of one OFDM symbol is T;

[0301] The duration T1 of the first signal satisfies:

[0302] T1=M*T*X-M*T / K*N;

[0303] The duration T2 of the second signal satisfies:

[0304] T2=M*T*(1-X) / N;

[0305] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0306] In a possible design, the sum of the number P1 of levels included in the first signal and 1 is proportional to the value of N.

[0307] In one possible design, the number P1 of levels included in the first signal satisfies:

[0308] P1=M*K*N*X-1;

[0309] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0310] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0311] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0312] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0313] The duration T3 of the third signal satisfies:

[0314] T3 = M*T - T1 - T2;

[0315] The number P3 of levels included in the third signal satisfies:

[0316] P3 = M*K*N - P1 - P2;

[0317] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer. In a possible design, P2 is equal to 4.

[0318] In a thirteenth aspect, the present application provides a communication device, which includes a processor, and the processor is used to execute a computer program so that the communication device executes any method described in any one of the first aspect to the sixth aspect.

[0319] In one possible design, the communication device may be a chip that implements the method of any one of the first to sixth aspects or a device including a chip.

[0320] In one possible design, the communication device further includes a transceiver, and the processor is coupled to the transceiver.

[0321] In a possible design, the communication device further includes a memory. The processor is coupled to the memory, a computer program is stored in the memory, and the processor is further used to call the computer program in the memory. Exemplarily, the processor and the memory may also be integrated together.

[0322] In a fourteenth aspect, the present application provides a communication device, which includes a processor, and the processor is used to implement any method described in any one of the first to sixth aspects through a logic circuit or execution code instructions.

[0323] Optionally, the communication device further includes an interface circuit, which is used to receive signals from other communication devices outside the communication device and transmit them to the processor or to send signals from the processor to other communication devices outside the communication device.

[0324] In a fifteenth aspect, the present application provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by a computer, the method described in any one of the first to sixth aspects is implemented.

[0325] In a sixteenth aspect, the present application provides a computer program product. When a computer reads and executes the computer program product, the computer executes any method described in any one of the first to sixth aspects.

[0326] In the seventeenth aspect, the present application provides a communication system, which includes a communication device for implementing the method described in any one of the first aspect, the second aspect, or the third aspect, and a communication device for implementing the method described in any one of the fourth aspect, the fifth aspect, or the sixth aspect.

[0327] In the eighteenth aspect, the present application also provides a communication method, wherein a network device is used to execute any method described in the above first aspect, and a tag is used to execute any method described in the above second aspect.

[0328] The beneficial effects of the fourth to eighteenth aspects can refer to the beneficial effects of the first to third aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0329] Figure 1 It is a schematic diagram of the architecture of a communication system to which the present application is applicable;

[0330] Figure 2 This is a schematic diagram of the data-0 signal;

[0331] Figure 3 It is a basic structural diagram of synchronization signal;

[0332] Figure 4 It is a flow chart of the communication method provided in the embodiment of the present application;

[0333] Figure 5 is a structural diagram of a synchronization signal provided in an embodiment of the present application;

[0334] Figure 6 This is a schematic diagram of the signal processing flow of DFT-S-OFDM;

[0335] Figure 7 is a structural diagram of a synchronization signal provided in an embodiment of the present application;

[0336] Figure 8 is a structural diagram of a synchronization signal provided in an embodiment of the present application;

[0337] Fig. 9 is a structural diagram of a synchronization signal provided in an embodiment of the present application;

[0338] Fig.10 is a structural diagram of a synchronization signal provided in an embodiment of the present application;

[0339] Fig.11 is a schematic diagram of a possible communication device provided in an embodiment of the present application;

[0340] Fig.12 It is a schematic diagram of the structure of another possible communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0341] The specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings.

[0342] The terms "first" and "second" and the like in the specification, claims and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0343] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0344] In the present application, "at least one (item)" means one or more, "more than one" means two or more, "at least two (items)" means two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0345] In this application, "sending information to... (such as a terminal)" can be understood as the destination of the information being the terminal. It can include sending information to the terminal directly or indirectly. "Receiving information from... (such as a terminal)" or "receiving information from... (such as a terminal)" can be understood as the source of the information being the terminal, which can include receiving information from the terminal directly or indirectly. The information may be processed as necessary between the source and destination of the information, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be understood similarly and will not be repeated here.

[0346] First, some terms or concepts involved in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0347] Passive Internet of Things refers to a transmission network including passive (battery free) nodes. Among them, the passive node itself is not equipped with or does not mainly rely on power devices such as batteries, but obtains energy from the environment to support the passive node to perceive, transmit and distribute data. In general, passive nodes may include passive tags or semi-passive tags, and the transceiver of the passive tag can be excited by a radio frequency field. In the embodiments of the present application, for the sake of simplicity, passive tags or semi-passive tags can be alternatively described as tags. Tags can form a radio-frequency identification (RFID) system together with network devices, and contactless automatic identification radio frequency technology can be applied in the RFID system.

[0348] RFID technology refers to an automatic identification technology that uses induction, radio waves or microwaves for non-contact two-way communication for the purpose of identification and data exchange. This technology can be used to manage the physical object where the tag is located.

[0349] Figure 1 The communication system 100 includes an RFID reader / writer (also referred to as a reader / writer, a card reader, etc., hereinafter referred to as a reader / writer) 101 and an RFID tag (hereinafter referred to as a tag) 102, wherein the reader / writer 101 and the tag 102 can communicate with each other via radio frequency (RF) signals.

[0350] The reader 101 can transmit an inquiry RF signal, and the tag 102 located near the reader 101 can detect the inquiry RF signal sent by the reader 101 and return a response RF signal to the reader 101. The response RF signal can carry the tag 102's own related information.

[0351] The reader / writer 101 can detect and interpret the reply RF signal.

[0352] In the embodiment of the present application, the reader / writer 101 can be understood as an entity on the network side for transmitting or receiving signals, or as a device that communicates with a tag, such as a terminal device, an access network device (such as a base station), or a device with reading and writing functions, etc. For the convenience of description, the specific embodiments below are mainly illustrated by taking network devices as an example.

[0353] The tag 102 in the embodiment of the present application may be a passive tag or a semi-passive tag. If the tag 102 is a passive tag, that is, the tag 102 itself does not have a power source, the tag 102 may obtain energy from the interrogation RF signal. Generally speaking, a passive / semi-passive tag may also be referred to as a passive / semi-passive Internet of Things device (the internet of things, IOT), which may be regarded as a terminal, such as a passive terminal device, a passive A-IoT terminal device, a semi-passive terminal device, a semi-passive A-IoT terminal device, or a terminal device with backscatter (carrier) capability, etc.

[0354] in:

[0355] Passive tags do not contain batteries or built-in batteries. When they are outside the reading range of the reader, the electronic tags are in a passive state. When they are within the reading range of the reader, the electronic tags extract the power required for their operation from the radio frequency energy emitted by the reader. Passive electronic tags generally use reflection modulation to complete the transmission of electronic tag information to the reader. The practical range of passive tags is about 10 cm to several meters. They are small in weight and volume and have a long service life, but their transmission distance is limited, and they require the reader to have a large transmission power and the transponder working circuit to have a small power consumption.

[0356] The battery power in a semi-passive tag only provides auxiliary support for the voltage required for the tag chip to work or the circuit that requires power to maintain data in the tag, and the tag circuit itself consumes very little power. Before the tag enters the working state, it is always in a dormant state, which is equivalent to a passive tag. The energy consumption of the battery inside the tag is very small, so the battery can be maintained for several years, or even up to 10 years. When the tag enters the reading area of ​​the reader, it is stimulated by the RF signal sent by the reader. When it enters the working state, the energy support for the information exchange between the tag and the reader is mainly the RF energy supplied by the reader (reflection modulation mode). The role of the battery inside the tag is mainly to make up for the insufficient RF field strength at the location of the tag. The energy of the battery inside the tag is not converted into RF energy.

[0357] It is understandable that there are other ways to classify tags: active, passive, and semi-active according to the modulation method. Read-only tags and read-write tags can be divided according to whether the stored information is rewritten. Credit card tags, linear tags, paper tags, glass tube tags, round tags, and special-purpose shaped tags can be divided according to the packaging form.

[0358] It should be understood that Figure 1 A reader / writer 101 and a tag 102 are shown as an example. Figure 1 In the architecture, one reader / writer 101 can communicate with multiple tags 102, and the communication system 100 can include multiple readers / writers 101, which is not limited in the embodiments of the present application.

[0359] Currently, the basic structure of the synchronization signal sent by the reader to the tag in RFID is delimiter+data-0+RTcal signal.

[0360] Delimiter signal: The delimiter signal is a delimiter. Before the delimiter, the tag receives a continuous high-level signal. The delimiter signal is a low-level signal that lasts for a period of time. When the tag detects that the low level lasts for a period of time, it knows that a time calibration signal will arrive later, and gradually starts to receive subsequent signals in the delimiter reception phase.

[0361] Data-0 signal: Data-0 signal is the signal after bit 0 is PIE encoded. The structure is a high level + low level signal. The total duration is 1Tari, where the high level and low level each occupy 0.5Tari. Figure 2 When the tag detects data-0, the high level and low level duration in data-0 can be detected through the rising or falling edge between the levels.

[0362] RTcal signal: The total duration of the RTcal signal is the duration corresponding to the data-0 signal plus the duration corresponding to the data-1 signal (the signal after bit 1 is PIE encoded). The total duration ranges from 2.5Tari≤RTcal≤3.0Tari. Therefore, by subtracting the duration of the data-0 signal from the total duration of the RTcal signal, it can be obtained that the duration of the data-1 signal is 1.5Tari≤the duration of the data-1 signal≤2.0Tari. The structure of the data-1 signal is still a high level + low level signal, in which the low level still occupies 0.5Tari. Therefore, the high level in data-1 occupies 1Tari≤the duration of the high level contained in the data-1 signal≤1.5Tari, which is 2 to 3 times the duration of the high level in data-0. Taking the high level in data-1 occupying 1.5Tari as an example, if the high level signal with a duration of 0.5Tari is quantized into the digital signal symbol {1}, and the low level signal of 0.5Tari is quantized into the digital signal symbol {0}, then the digital signal corresponding to data-0 can be expressed as {10}, and the digital signal corresponding to data-1 can be expressed as {1110}; that is, it can also be understood that bit 0 becomes the symbol {10} after PIE encoding, and bit 1 becomes the symbol {1110} after PIE encoding. After detecting the RTcal signal, the tag can detect the duration of the high level and the duration of the low level in data-1 according to the rising or falling edge between the levels (this information has been obtained when detecting the data-0 signal), such as Figure 3 Schematic diagram of the basic structure of the synchronization signal.

[0363] Therefore, through the data-0 signal and the RTcal signal, the tag effectively obtains the level duration of data-0 and data-1, and obtains the clock boundary (symbol boundary) information of the signal through the rising and falling edges of the signal, which is equivalent to a time calibration process. Therefore, the data-0 signal and the RTcal signal can also be called the time calibration signal of the passive tag.

[0364] From the above introduction, it can be seen that the current tags (i.e. passive tags or semi-passive tags) mainly use the PIE encoding method. The high level lengths in the coding patterns corresponding to bit 0 and bit 1 are different and the high level accounts for ≥50% of the total level duration in the entire coding pattern. PIE coding, which is a type of high-level coding with unequal lengths, can enable the tag to receive more RF energy during data transmission, thereby better maintaining the tag's communication. However, in actual implementation, the tag circuit usually contains an energy storage capacitor that can store energy to support subsequent communications for a period of time. Therefore, PIE coding, which enables tags to receive more high-level energy, is no longer necessary. In addition, as introduced above, the bit pattern of PIE coding after bit 0 coding is {10}, and the bit pattern after bit 1 coding is {1110}. The bit patterns after the two codings are very similar, and the average code distance between code words is extremely small. When demodulating at the receiving end, the probability of wrong judgment is obviously not as good as Manchester coding (the bit pattern after bit 0 coding is {10}, and the bit pattern after bit 1 coding is {01}). The bit pattern of the code word in Manchester coding is completely opposite, and the average code distance is the maximum value. Therefore, when demodulating at the receiving end, the performance of Manchester coding is significantly better than PIE coding. And the high level of Manchester coding accounts for 50% of the total level duration, which can also better meet the tag's demand for RF energy. In addition, when the synchronization signal is currently designed, only the design when the downlink signal bandwidth is 12 subcarriers is considered. If the configured downlink signal bandwidth is greater than 12 subcarriers (for example, 24 or 48 subcarriers, etc.), then the current synchronization signal design will not be compatible with a wider downlink signal bandwidth.

[0365] Based on this, the present application proposes a communication method and related devices, which are compatible with the design of synchronization signals for passive / semi-passive tags under different downlink signal bandwidths, which is conducive to improving communication performance. In addition, the synchronization signal involved in the embodiment of the present application uses a Manchester encoding method with better performance, which is conducive to improving the demodulation performance of the receiving end.

[0366] The communication method and communication device provided by this application are described in detail below:

[0367] See also Figure 4 , Figure 4 is a flow chart of the communication method provided in the embodiment of the present application. Figure 4 As shown, the communication method includes the following steps S401-S402. Figure 4 The execution subject of the method shown may be a network device and a tag (i.e., a passive tag or a semi-passive tag, hereinafter referred to as a tag, it should be noted that the tag in the embodiment of the present application may be understood as a terminal), or, Figure 4The execution subject of the method shown can also be a chip in a network device or a chip in a tag. Figure 4 The following mainly uses network devices and tags as the execution subjects of the method. It should be noted that Figure 4 is a schematic flow chart of a method embodiment of the present application, showing detailed communication steps or operations of the method, but these steps or operations are only examples, and the present application embodiment may also perform other operations or Figure 4 In addition, Figure 4 The steps in Figure 4 are executed in a different order than those presented, and may not be executed in the order Figure 4 All operations in . Among them:

[0368] S401. A network device determines a synchronization signal.

[0369] Among them, the synchronization signal can also be called the synchronization signal of the passive tag, or the leading signal, or the leading signal of the data signal, or the leading signal of the passive tag, or the leading signal of the passive tag data signal, etc. These names are just examples, and other names can be used in specific implementations. This application does not make specific limitations on this.

[0370] S402: The network device sends the synchronization signal to the tag on the first time domain resource and the first frequency domain resource. Correspondingly, the tag receives the synchronization signal from the network device on the first time domain resource and the first frequency domain resource.

[0371] Here, the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing (OFDM) symbols, and preferably, the value of M is equal to 1. The first frequency domain resource includes N*12 subcarriers, or is described as the first frequency domain resource including N resource blocks (RBs). Wherein, M and N are both positive integers, and preferably, M is fixed to 1.

[0372] It should be understood that the modulation mode of the synchronization signal involved in the embodiment of the present application can be on-off keying (OOK) or binary amplitude shift keying (2ASK), so all descriptions of "OOK" in this article can also be replaced by "2ASK". For ease of understanding, the following text is mainly explained with the expression of OOK. Among them, the synchronization signal includes a first signal and a second signal, where the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal (that is, if the first signal exists, it means that the transmission of the second signal immediately exists after the transmission of the first signal ends, and "immediately exists" here means that there is no time interval (gap) between the first signal and the second signal), or it is described as that the first signal indicates that there is a transmission of the second signal after the first signal, or it is understood that the first signal is a signal between the energy signal and the second signal. The second signal is used for time calibration, and here "time calibration" has two functions of "determining the duration of the unit level / 1 level" and "determining the time boundary of the data signal". Generally speaking, there is a transmission of the data signal immediately after the transmission of the second signal ends. It should be noted that the first signal may also be referred to as a delimiter signal or a delimiter or a passive tag delimiter, etc., and the second signal may also be referred to as a time calibration signal or a calibration signal or a symbol synchronization signal or a level calibration signal, etc., and the present application does not limit this. Optionally, the first signal may also be a part of the delimiter signal. The levels involved in the present application are sometimes also referred to as OOK chips, OOK symbols, or OOK segments, etc., and the embodiments of the present application do not specifically limit this.

[0373] It should be noted that, with respect to the design of the first signal and the second signal in the synchronization signal, the present application mainly proposes three possible implementation methods, and these three possible implementation methods will be described respectively below.

[0374] Method 1:

[0375] In the following embodiment, a synchronization signal is designed to include a first signal and a second signal, wherein a first time domain resource used to transmit the synchronization signal includes M OFDM symbols (or described as the duration of the first time domain resource being equal to the duration of M OFDM symbols), or, it is understood that the sum of the durations of the first signal and the second signal is equal to the duration of M OFDM symbols.

[0376] Exemplarily, any level included in the first signal may be the first level, that is, the first signal is a full {0} (or full low level) signal. Optionally, the first signal may also be a signal of a predefined / preset pattern, for example, the first signal may be a signal of a combination pattern of {01} and {10}, etc., and the present application does not limit this. It should be understood that when the first signal is a full low level signal, this design of the first signal can avoid confusion between the first signal and the subsequent second signal and the data signal as much as possible, which is conducive to improving the demodulation performance. Therefore, the following mainly takes the first signal as a full low level signal as an example for schematic description.

[0377] The second signal includes at least one first level and at least one second level, and the number of first levels included in the second signal is equal to the number of second levels, that is, the second signal is a signal with equal numbers of {0} and {1} (or the number of low levels is equal to the number of high levels). The second level is higher than the first level, and the second level can also be called a high level, or an OOK symbol {1} ​​or an OOK chip {1}, and the first level can also be called a low level, or an OOK symbol {0} or an OOK chip {0}, etc., which is not specifically limited in the embodiments of the present application.

[0378] Exemplarily, the second signal may be a signal of a predefined / preset pattern, for example, the second signal may be a signal of a combination pattern of {01} and {10}, such as {01100110} or {01011010}, etc. Again exemplarily, the pattern of the second signal may also be other patterns satisfying that the number of first levels is equal to the number of second levels, for example, the second signal is {01101010} or {10010101}, etc., and the present application does not limit this.

[0379] Exemplarily, the second signal may be one of a plurality of predefined / preset pattern signals, wherein different preset patterns may indicate different subcarrier spacings of the data signal, or different preset patterns may indicate different CP lengths of the data signal. For example, the second signal may be one of two predefined pattern signals, and taking the two predefined patterns {01100110} and {10011001} as examples, when the preset pattern of the second signal is {01100110}, it may indicate that the subcarrier spacing of the data signal is 15kHz, and when the preset pattern of the second signal is {10011001}, it may indicate that the subcarrier spacing of the data signal is 30kHz. Alternatively, when the preset pattern of the second signal is {01100110}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 15kHz, and when the preset pattern of the second signal is {10011001}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 30kHz.

[0380] It should be understood that, in addition to the number of first levels contained in the second signal involved in the present application being equal to the number of second levels, the second signal may also satisfy: any adjacent level of the first level included in the second signal may be the second level, and any adjacent level of the second level included in the second signal may be the first level. Exemplarily, in one case, the first level in the second signal is the first level, and the last level of the second signal is the second level, that is, the second signal may be a signal in which {0} and {1} appear alternately, for example, the second signal is {010101}. Again exemplarily, in another case, the first level in the second signal is the second level, and the last level of the second signal is the first level, that is, the second signal may also be a signal in which {1} and {0} appear alternately, for example, {101010}. Preferably, the second signal is a signal in which {1} and {0} appear alternately.

[0381] Exemplarily, the second signal may be one of a signal in which {0} and {1} appear alternately and a signal in which {1} and {0} appear alternately, for example, one of {010101} and {101010}. Different forms of the second signal may indicate different subcarrier spacings or different CP lengths of the data signal. For example, when the preset pattern of the second signal is {010101}, it may indicate that the subcarrier spacing of the data signal is 15kHz, and when the preset pattern of the second signal is {101010}, it may indicate that the subcarrier spacing of the data signal is 30kHz. Alternatively, when the preset pattern of the second signal is {010101}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 15kHz, and when the preset pattern of the second signal is {101010}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 30kHz.

[0382] It should be noted that, in the present application, the duration of the second level is equal to the duration of the first level.

[0383] Optionally, the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, that is, the duration T1 of the first signal and the duration T2 of the second signal do not change with the value of N, and the sum of the duration T1 of the first signal and the duration T2 of the second signal is equal to the duration of M OFDM symbols, that is, T1+T2=M*T. Wherein, T here represents the duration of an OFDM symbol, or represents the duration of an OFDM symbol before a cyclic prefix (CP) is added. Generally speaking, the duration of an OFDM symbol is the inverse of the subcarrier spacing. For example, when the subcarrier spacing is equal to 15kHz, the duration of an OFDM symbol is 1 / 15kHz=66.6us. For another example, when the subcarrier spacing is equal to 30kHz, the duration of an OFDM symbol is 1 / 30kHz=33.3us.

[0384] Optionally, the duration T1 of the first signal may satisfy: T1 = M*T*X, and the duration T2 of the second signal may satisfy: T2 = M*T*(1-X), where 0 < X ​​< 1. It should be understood that, in the case of M = 1, the value of X is associated with the subcarrier spacing, for example, in the case where M is equal to 1 and K is equal to 6, if the subcarrier spacing is 15kHz, then X = 1 / 3, because the duration of the first signal must not be shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs); in the case where M is equal to 1 and K is equal to 6, if the subcarrier spacing is 30kHz, then X = 1 / 2, because the duration of the first signal must not be shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs). Here, K is the number of levels included in one OFDM symbol when N is equal to 1 (that is, K is the number of levels included in one OFDM symbol when the first frequency domain resource includes 12 subcarriers). When N is greater than 1, the number of levels included in one OFDM symbol is K*N. It should be noted that when M is equal to 1, K is equal to 6, and the subcarrier spacing is 15kHz, X=1 / 3 is the preferred solution, and X=1 / 2 is the second preferred solution; when M is equal to 1, K is equal to 6, and the subcarrier spacing is 30kHz, X=1 / 2 is the preferred solution. For the convenience of description, for method one, the following mainly takes X=1 / 3 as an example when M is equal to 1, K is equal to 6, and the subcarrier spacing is 15kHz for schematic explanation.

[0385] Optionally, the number of levels P1 included in the first signal is proportional to the value of N, and the number of levels P2 included in the second signal is proportional to the value of N. Exemplarily, the number of levels P1 included in the first signal can satisfy: P1 = M*K*N*X, and the number of levels P2 included in the second signal can satisfy: P2 = M*K*N*(1-X). Wherein, 0 < X ​​< 1, K is the number of levels included in an OFDM symbol when N is equal to 1 (that is, K is the number of levels included in 1 OFDM symbol when the first frequency domain resource includes 12 subcarriers), and when N is greater than 1, the number of levels included in an OFDM symbol is K*N, and K is usually a positive integer. Generally speaking, when M is equal to 1 and X is a fixed value, the ratio of the number of levels P1 included in the first signal to N is K, and the ratio of the number of levels P1 included in the second signal to N is K.

[0386] Optionally, when K is equal to 6 and M is equal to 1, the total number of levels included in the synchronization signal of mode 1 is 6*N.

[0387] Optionally, when K is equal to 6, the number P1 of the levels included in the first signal is generally an integer not less than 2 (i.e., P1 ≥ 2, and P is an integer), the number P2 of the levels included in the second signal is generally an integer not less than 2 (i.e., P2 ≥ 2, and P is an integer), or the number P2 of the levels included in the second signal is an integer not less than 4 (i.e., P2 ≥ 4, and P is an integer). Preferably, the number P2 of the levels included in the second signal is greater than or equal to 4, because when P2 is not less than 4, the number of rising edges or falling edges of the levels that can be used when the tag performs clock calibration can be effectively guaranteed, and the detection error of the detection level boundary (symbol boundary) is guaranteed to be small.

[0388] For ease of understanding, the following text mainly uses M=1, K=6, X=1 / 3 as an example for exemplary explanation. When the first time domain resource includes 1 OFDM symbol (that is, the duration of the synchronization signal is 1 OFDM symbol), the duration of the first signal is 1 / 3 of the duration of an OFDM symbol, and the number of levels included in the first signal is 6*N*1 / 3; the duration of the second signal is 2 / 3 of the duration of an OFDM symbol, and the number of levels included in the second signal is 6*N*2 / 3.

[0389] For example, see Figure 5 , Figure 5 is a schematic diagram of a structure of a synchronization signal provided in an embodiment of the present application. Figure 5As shown, taking the subcarrier spacing of 15kHz as an example, when the duration of the synchronization signal is 1 OFDM symbol (i.e., M=1, which is equivalent to the duration of the synchronization signal being 66.6μs), K=6, and X=1 / 3, if the first signal is a full {0} signal and the second signal is a signal in which {0} and {1} levels appear alternately, then:

[0390] When N is equal to 1, the number of levels contained in the first signal is 2 (i.e., the first signal is {00}), and the number of levels contained in the second signal is 4 (i.e., the second signal is {0101}). When the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0391] When N is equal to 2, the number of levels contained in the first signal is 4 (that is, the first signal is {0000}), and the number of levels contained in the second signal is 8 (that is, the second signal is {01010101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0392] When N is equal to 3, the number of levels contained in the first signal is 6 (that is, the first signal is {000000}), and the number of levels contained in the second signal is 12 (that is, the second signal is {010101010101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0393] When N is equal to 4, the first signal contains 8 levels (that is, the first signal is {00000000}), and the second signal contains 16 levels (that is, the second signal is {0101010101010101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0394] Depend on Figure 5 It can be seen that when the subcarrier spacing is equal to 15kHz, before adding CP, the duration of the first signal is T1 = 1 / 3*66.6μs, that is, 22.2μs; the duration of the second signal is T2 = 2 / 3*66.6μs, that is, 44.4μs. The number of levels contained in the first signal is 6*N*1 / 3, and the number of levels contained in the second signal is 6*N*2 / 3.

[0395] Optionally, in this application, the network device may specifically adopt the following Figure 6The discrete Fourier transform-spreading-orthogonal frequency division multiplexing (DFT-S-OFDM) generation method shown processes the synchronization signal and then sends it, wherein the length of the discrete Fourier transform (DFT) input sequence is N*12, and the pattern of the DFT input sequence is a level pattern composed of all levels contained in the first signal and the second signal, each level is repeated a number of times equal to 12 / K, for example, when K is equal to 6, the number of repetitions is equal to 2. Exemplarily, when the duration of the synchronization signal is 1 OFDM symbol (i.e., M=1), when N is equal to 1, the level contained in the first signal is {00}, and the level contained in the second signal is {0101}. By repeating each level in the first signal and the second signal twice (i.e., the number of repetitions of each level is equal to 2), the levels {0000} and {00110011} can be obtained, and the level pattern is {000000110011}, that is, the DFT input sequence is {000000110011}.

[0396] Based on the design of method 1, the performance of the synchronization signal in the passive Internet of Things system can be effectively guaranteed, wherein the duration of the first signal remains unchanged under different bandwidths, and is not shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs) (that is, the first signal is equivalent to the delimiter signal), which can effectively guarantee the buffer time for data reception when the tag is started. The number of levels included in the second signal is ≥4 (preferred), which can effectively guarantee the number of levels that can be used when the tag performs clock calibration, which is conducive to improving the accuracy of obtaining the level boundary (symbol boundary) during detection.

[0397] Method 2:

[0398] In method 2, a synchronization signal is designed to include a first signal and a second signal, wherein the duration of the first time domain resource used to transmit the synchronization signal is less than or equal to the duration of M OFDM symbols, or, it is understood that the sum of the durations of the first signal and the second signal is less than or equal to the duration of M OFDM symbols.

[0399] Exemplarily, any level included in the first signal may be the first level, that is, the first signal is a full {0} (or full low level) signal. Optionally, the first signal may also be a signal of a predefined / preset pattern, for example, the first signal may be a signal of a combination pattern of {01} and {10}, etc., and the present application does not limit this. It should be understood that when the first signal is a full low level signal, this design of the first signal can avoid confusion between the first signal and the subsequent second signal and the data signal as much as possible, which is conducive to improving the demodulation performance. Therefore, the following mainly takes the first signal as a full low level signal as an example for schematic description.

[0400] The second signal includes at least one first level and at least one second level, and the number of first levels included in the second signal is equal to the number of second levels, that is, the second signal is a signal with equal numbers of {0} and {1} (or the number of low levels is equal to the number of high levels). The second level is higher than the first level, and the second level can also be called a high level, or an OOK symbol {1} ​​or an OOK chip {1}, and the first level can also be called a low level, or an OOK symbol {0} or an OOK chip {0}, etc., which is not specifically limited in the embodiments of the present application.

[0401] Exemplarily, the second signal may be a signal of a predefined / preset pattern, for example, the second signal may be a signal of a combination pattern of {01} and {10}, such as {0110} or {1001}, etc. Again exemplarily, the pattern of the second signal may also be other patterns satisfying that the number of first levels is equal to the number of second levels, etc., and the present application does not limit this.

[0402] Exemplarily, the second signal may be one of a plurality of predefined / preset pattern signals, wherein different preset patterns may indicate different subcarrier spacings of the data signal, or different preset patterns may indicate different CP lengths of the data signal. For example, the second signal may be one of two predefined pattern signals, and taking the two predefined patterns {0110} and {1001} as examples, when the preset pattern of the second signal is {0110}, it may indicate that the subcarrier spacing of the data signal is 15kHz, and when the preset pattern of the second signal is {1001}, it may indicate that the subcarrier spacing of the data signal is 30kHz. Alternatively, when the preset pattern of the second signal is {0110}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 15kHz, and when the preset pattern of the second signal is {1001}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 30kHz.

[0403] It should be understood that, in addition to the number of first levels contained in the second signal involved in the present application being equal to the number of second levels, any adjacent level of the first level included in the second signal may be the second level, and any adjacent level of the second level included in the second signal may be the first level. Exemplarily, in one case, the first level in the second signal is the first level, and the last level of the second signal is the second level, that is, the second signal may be a signal in which {0} and {1} appear alternately, for example, the second signal is {0101}. Again exemplarily, in another case, the first level in the second signal is the second level, and the last level of the second signal is the first level, that is, the second signal may also be a signal in which {1} and {0} appear alternately, for example, {1010}. Preferably, the second signal is a signal in which {1} and {0} appear alternately.

[0404] Exemplarily, the second signal may be one of a signal in which {0} and {1} appear alternately and a signal in which {1} and {0} appear alternately, for example, one of {0101} and {1010}. Different forms of the second signal may indicate different subcarrier spacings or different CP lengths of the data signal. For example, when the preset pattern of the second signal is {0101}, it may indicate that the subcarrier spacing of the data signal is 15kHz, and when the preset pattern of the second signal is {1010}, it may indicate that the subcarrier spacing of the data signal is 30kHz. Alternatively, when the preset pattern of the second signal is {0101}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 15kHz, and when the preset pattern of the second signal is {1010}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 30kHz.

[0405] It should be noted that, in the present application, the duration of the second level is equal to the duration of the first level.

[0406] Optionally, the duration T1 of the first signal is a fixed value, that is, the duration T1 of the first signal does not change with the value of N. Optionally, the duration T2 of the second signal is inversely proportional to the value of N.

[0407] Exemplarily, the duration T1 of the first signal may satisfy: T1 = M*T*X, and the duration T2 of the second signal may satisfy: T2 = M*T*(1-X) / N. Here, T represents the duration of an OFDM symbol, or represents the duration of an OFDM symbol before CP is added. Generally speaking, the duration of an OFDM symbol is the reciprocal of the subcarrier spacing. For example, when the subcarrier spacing is equal to 15kHz, the duration of an OFDM symbol is 1 / 15kHz = 66.6us. For another example, when the subcarrier spacing is equal to 30kHz, the duration of an OFDM symbol is 1 / 30kHz = 33.3us.

[0408] It should be noted that the above X should satisfy: 0<X<1. It should be understood that when M=1, the value of X is associated with the subcarrier spacing. For example, when M is equal to 1 and K is equal to 6, if the subcarrier spacing is 15kHz, then X=1 / 3, because the duration of the first signal must not be shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs); when M is equal to 1 and K is equal to 6, if the subcarrier spacing is 30kHz, then X=1 / 2, because the duration of the first signal must not be shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs). Here, K is the number of levels included in an OFDM symbol when N is equal to 1 (that is, K is the number of levels included in one OFDM symbol when the first frequency domain resource includes 12 subcarriers), and when N is greater than 1, the number of levels included in one OFDM symbol is K*N. It should be noted that when M is equal to 1, K is equal to 6, and the subcarrier spacing is 15kHz, X=1 / 3 is the preferred solution, and X=1 / 2 is the second preferred solution; when M is equal to 1, K is equal to 6, and the subcarrier spacing is 30kHz, X=1 / 2 is the preferred solution. For the convenience of description, for the second method, the following mainly takes M equal to 1, K equal to 6, and the subcarrier spacing is 15kHz, X=1 / 3 as an example for schematic description.

[0409] Optionally, the number of levels P1 included in the first signal is proportional to the value of N. The number of levels P2 included in the second signal is a fixed value, that is, the number of levels included in the second signal does not change with the value of N. For example, P2 can be any integer not less than 2 or not less than 4. For example, the value of P2 is fixed to 4, which can effectively ensure the number of levels that can be used when the tag performs clock calibration, and ensure the accuracy of obtaining the level boundary (symbol boundary) during detection. Exemplarily, the number of levels P1 included in the first signal can satisfy: P1 = M*K*N*X. Wherein, 0 <X <1, K is the number of levels included in an OFDM symbol when N is equal to 1 (that is, K is the number of levels included in 1 OFDM symbol when the first frequency domain resource includes 12 subcarriers), when N is greater than 1, the number of levels included in an OFDM symbol is K*N, and K is usually a positive integer.

[0410] Optionally, when K is equal to 6, the number P1 of levels included in the first signal is generally an integer not less than 2 (ie, P1 ≥ 2, and P is an integer).

[0411] For ease of understanding, the following text mainly uses M=1, K=6, X=1 / 3, and P2=4 as an example for illustrative explanation. When the duration of the first time domain resource is less than or equal to the duration of one OFDM symbol (that is, the duration of the synchronization signal is less than or equal to the duration of one OFDM symbol), the duration of the first signal is 1 / 3 of the duration of an OFDM symbol, and the number of levels contained in the first signal is 6*N*1 / 3; the duration of the second signal is inversely proportional to the value of N, and the number of levels contained in the second signal is fixed at 4.

[0412] For example, see Figure 7 , Figure 7 is another structural diagram of the synchronization signal provided in the embodiment of the present application. Figure 7 As shown, taking the subcarrier spacing equal to 15kHz as an example, when the duration of the synchronization signal is less than or equal to the duration of 1 (i.e., M=1) OFDM symbol (equivalent to the duration of the synchronization signal being less than or equal to 66.6μs), K=6, X=1 / 3, and P2=4, if the first signal is a full {0} signal and the second signal is a signal in which {0} and {1} levels appear alternately, then:

[0413] When N is equal to 1, the number of levels contained in the first signal is 2 (i.e., the first signal is {00}), and the number of levels contained in the second signal is 4 (i.e., the second signal is {0101}). When the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0414] When N is equal to 2, the number of levels contained in the first signal is 4 (that is, the first signal is {0000}), and the number of levels contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 22.2μs.

[0415] When N is equal to 3, the number of levels contained in the first signal is 6 (that is, the first signal is {000000}), and the number of levels contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 14.8μs.

[0416] When N is equal to 4, the first signal contains 8 levels (that is, the first signal is {00000000}), and the second signal contains 4 levels (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 11.1μs.

[0417] Depend on Figure 7 It can be seen that when the subcarrier spacing is equal to 15kHz, before adding CP, the duration of the first signal is T1 = 1 / 3*66.6μs, that is, 22.2μs. The duration of the second signal is inversely proportional to the value of N. When N is equal to 1, the duration of the second signal is 44.4μs, when N is equal to 2, the duration of the second signal is 22.2μs, when N is equal to 3, the duration of the second signal is 14.8μs, and when N is equal to 4, the duration of the second signal is 11.1μs. The number of levels contained in the first signal is 6*N*1 / 3, and the number of levels contained in the second signal is fixed to 4.

[0418] Under method two, another design is that the synchronization signal includes a first signal, a second signal and a third signal, wherein the duration of the first time domain resource used to transmit the synchronization signal is equal to the duration of M OFDM symbols, or, it is understood that the sum of the durations of the first signal, the second signal and the third signal is equal to the duration of M OFDM symbols.

[0419] Among them, the third signal is before the first signal, that is, the arrangement order of the first signal, the second signal, and the third signal in the synchronization signal is {third signal, first signal, second signal}. Exemplarily, any level included in the third signal can be the second level, that is, the third signal is a full {1} ​​(or full high level) signal, which is conducive to the tag to obtain more energy and maintain normal communication.

[0420] It should be understood that since the sum of the durations of the first signal, the second signal and the third signal is equal to the duration of M OFDM symbols, the duration T3 of the third signal can satisfy: T3 = M*T-T1-T2. Optionally, the number of levels P3 included in the third signal can satisfy: P3 = M*K*N-P1-P2. Wherein, K is the number of levels included in an OFDM symbol when N is equal to 1, and K is a positive integer. Here, M*K*N is the total number of levels included in the synchronization signal. When K is equal to 6 and M is equal to 1, the total number of levels included in the synchronization signal of mode 2 is 6*N, so the number of levels P3 included in the third signal satisfies: P3 = 6*N-6*N*X-P2.

[0421] For example, see Figure 8 , Figure 8 is another structural diagram of the synchronization signal provided in the embodiment of the present application. Figure 8 As shown, taking the subcarrier spacing of 15kHz as an example, when the duration of the synchronization signal is equal to the duration of 1 (i.e., M=1) OFDM symbol (equivalent to the duration of the synchronization signal being equal to 66.6μs), K=6, X=1 / 3, and P2=4, if the third signal is an all-{1} signal, the first signal is an all-{0} signal, and the second signal is a signal in which {0} and {1} levels appear alternately, then:

[0422] When N is equal to 1, the number of levels included in the third signal is 0 (i.e., there is no third signal), the number of levels included in the first signal is 2 (i.e., the first signal is {00}), and the number of levels included in the second signal is 4 (i.e., the second signal is {0101}). When the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 0μs, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0423] When N is equal to 2, the number of levels included in the third signal is 4 (i.e., the third signal is {1111}), the number of levels included in the first signal is 4 (i.e., the first signal is {0000}), and the number of levels included in the second signal is 4 (i.e., the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 22.2μs, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 22.2μs.

[0424] When N is equal to 3, the number of levels contained in the third signal is 8 (that is, the third signal is {11111111}), the number of levels contained in the first signal is 6 (that is, the first signal is {000000}), and the number of levels contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 29.6μs, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 14.8μs.

[0425] When N is equal to 4, the number of levels included in the third signal is 12 (that is, the third signal is {111111111111}), the number of levels included in the first signal is 8 (that is, the first signal is {00000000}), and the number of levels included in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 33.3μs, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 11.1μs.

[0426] Depend on Figure 8 It can be seen that when the subcarrier spacing is equal to 15kHz, before adding CP, the duration of the first signal T1 = 1 / 3 * the duration of an OFDM symbol, that is, 22.2μs. The duration of the second signal is inversely proportional to the value of N. When N is equal to 1, the duration of the second signal is 44.4μs, when N is equal to 2, the duration of the second signal is 22.2μs, when N is equal to 3, the duration of the second signal is 14.8μs, and when N is equal to 4, the duration of the second signal is 11.1μs. The duration of the third signal T3 = 66.6μs - T1 - T2. The number of levels contained in the first signal is 6*N*1 / 3, the number of levels contained in the second signal is fixed to 4, and the number of levels contained in the third signal P3 = 6*N-6*N*1 / 3-4.

[0427] Optionally, in this application, the network device may specifically adopt the following Figure 6The DFT-S-OFDM generation mode shown processes the synchronization signal and then sends it, wherein the length of the DFT input sequence is N*12, the pattern of the DFT input sequence is the third signal, and the first signal and the second signal contain all levels, each of which is repeated a number of times equal to 12 / K, and for example, when K is equal to 6, the number of repetitions is equal to 2. Exemplarily, when the duration of the synchronization signal is 1 OFDM symbol (i.e., M=1), when N is equal to 2, the level contained in the third signal is {1111}, the level of the first signal is {0000}, and the level contained in the second signal is {0101}. By repeating each level in the third signal, the first signal, and the second signal by one time (i.e., the number of repetitions of each level is equal to 2), the levels {11111111}, {00000000}, and {00110011} can be obtained, that is, the DFT input sequence is {111111110000000000110011}.

[0428] Based on the design of the second method, the performance of the synchronization signal in the passive IoT system can be effectively guaranteed, wherein the duration of the first signal remains unchanged under different bandwidths, and is not shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs). Therefore, the first signal here is equivalent to the delimiter signal, which can effectively guarantee the buffer time for data reception when the tag is started. The number of levels contained in the second signal is fixed to 4, which effectively guarantees the number of levels that can be used when the tag performs clock calibration, while maximizing the peak transmission rate of the (passive or semi-passive) tag as much as possible.

[0429] Method 3:

[0430] Under mode three, a synchronization signal is designed to include a first signal and a second signal, wherein the duration of the first time domain resource used to transmit the synchronization signal is less than or equal to the duration of M OFDM symbols, or, it is understood that the sum of the durations of the first signal and the second signal is less than or equal to the duration of M OFDM symbols.

[0431] Exemplarily, any level included in the first signal may be the first level, that is, the first signal is a full {0} (or full low level) signal. Optionally, the first signal may also be a signal of a predefined / preset pattern, for example, the first signal may be a signal of a combination pattern of {01} and {10}, etc., and the present application does not limit this. It should be understood that when the first signal is a full low level signal, this design of the first signal can avoid confusion between the first signal and the subsequent second signal and the data signal as much as possible, which is conducive to improving the demodulation performance. Therefore, the following mainly takes the first signal as a full low level signal as an example for schematic description.

[0432] The second signal includes at least one first level and at least one second level, and the number of first levels included in the second signal is equal to the number of second levels, that is, the second signal is a signal with equal numbers of {0} and {1} (or the number of low levels is equal to the number of high levels). The second level is higher than the first level, and the second level can also be called a high level, or an OOK symbol {1} ​​or an OOK chip {1}, and the first level can also be called a low level, or an OOK symbol {0} or an OOK chip {0}, etc., which is not specifically limited in the embodiments of the present application.

[0433] Exemplarily, the second signal may be a signal of a predefined / preset pattern. Optionally, the second signal may also satisfy: the first level in the second signal may be the first level. For example, the second signal may be a signal of a combination pattern of {01} and {10}, such as {0110} or {1001}, etc., and the present application does not limit this.

[0434] Exemplarily, the second signal may be one of a plurality of predefined / preset pattern signals, wherein different preset patterns may indicate different subcarrier spacings of the data signal, or different preset patterns may indicate different CP lengths of the data signal. For example, the second signal may be one of two predefined pattern signals, and taking the two predefined patterns {0110} and {1001} as examples, when the preset pattern of the second signal is {0110}, it may indicate that the subcarrier spacing of the data signal is 15kHz, and when the preset pattern of the second signal is {1001}, it may indicate that the subcarrier spacing of the data signal is 30kHz. Alternatively, when the preset pattern of the second signal is {0110}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 15kHz, and when the preset pattern of the second signal is {1001}, it may indicate that the CP length of the data signal is the CP length corresponding to the subcarrier spacing of 30kHz.

[0435] As another example, in addition to the number of first levels contained in the second signal involved in the present application being equal to the number of second levels, the second signal may also satisfy: any adjacent level of the first level included in the second signal may be the second level, and any adjacent level of the second level included in the second signal may be the first level. Optionally, the second signal may also satisfy: the first level in the second signal may be the first level, and the last level of the second signal may be the second level. As an example, the second signal may be a signal in which {0} and {1} appear alternately, for example, the second signal is {0101}.

[0436] Preferably, the second signal is a signal in which {0} and {1} appear alternately.

[0437] It should be noted that, in the present application, the duration of the second level is equal to the duration of the first level.

[0438] Optionally, the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, that is, the sum of the duration T1 of the first signal and the duration of one first level does not change with the value of N. Optionally, the duration T2 of the second signal is inversely proportional to the value of N.

[0439] Exemplarily, the duration T1 of the first signal may satisfy: T1 = M*T*X - M*T / K*N, where M*T / K*N represents the duration of the unit level. The duration T2 of the second signal may satisfy: T2 = M*T*(1-X) / N. Here T represents the duration of an OFDM symbol, or the duration of an OFDM symbol before the CP is added. Generally speaking, the duration of an OFDM symbol is the reciprocal of the subcarrier spacing. For example, when the subcarrier spacing is equal to 15kHz, the duration of an OFDM symbol is 1 / 15kHz = 66.6us. For another example, when the subcarrier spacing is equal to 30kHz, the duration of an OFDM symbol is 1 / 30kHz = 33.3us.

[0440] It should be noted that the above X should satisfy: 0<X<1. It should be understood that when M=1, the value of X is associated with the subcarrier spacing. For example, when M is equal to 1 and K is equal to 6, if the subcarrier spacing is 15kHz, then X=1 / 3, because the duration of the first signal must not be shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs); when M is equal to 1 and K is equal to 6, if the subcarrier spacing is 30kHz, then X=1 / 2, because the duration of the first signal must not be shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs). Here, K is the number of levels included in an OFDM symbol when N is equal to 1 (that is, K is the number of levels included in one OFDM symbol when the first frequency domain resource includes 12 subcarriers), and when N is greater than 1, the number of levels included in one OFDM symbol is K*N. It should be noted that when M is equal to 1, K is equal to 6, and the subcarrier spacing is 15kHz, X=1 / 3 is the preferred solution, and X=1 / 2 is the second preferred solution; when M is equal to 1, K is equal to 6, and the subcarrier spacing is 30kHz, X=1 / 2 is the preferred solution. For the convenience of description, for method 3, the following mainly takes M equal to 1, K equal to 6, and the subcarrier spacing is 15kHz, X=1 / 2 as an example for schematic description.

[0441] Optionally, the sum of the number of levels P1 and 1 included in the first signal is proportional to the value of N. The number of levels P2 included in the second signal is a fixed value, that is, the number of levels included in the second signal does not change with the value of N. For example, P2 can be any integer not less than 2 or not less than 4. For example, the value of P2 is fixed to 4, which can effectively ensure the number of levels that can be used when the tag performs clock calibration, and ensure the accuracy of obtaining the level boundary (symbol boundary) during detection. Exemplarily, the number of levels P1 included in the first signal can satisfy: P1 = M*K*N*X-1. Wherein, 0 <X <1, K is the number of levels included in an OFDM symbol when N is equal to 1 (that is, K is the number of levels included in 1 OFDM symbol when the first frequency domain resource includes 12 subcarriers), when N is greater than 1, the number of levels included in an OFDM symbol is K*N, and K is usually a positive integer.

[0442] Optionally, when K is equal to 6, the number P1 of levels included in the first signal is generally an integer not less than 2 (ie, P1 ≥ 2, and P is an integer).

[0443] For ease of understanding, the following text mainly uses M=1, K=6, X=1 / 2, P2=4 as an example for illustrative explanation. When the first time domain resource includes 1 OFDM symbol (that is, the duration of the synchronization signal is 1 OFDM symbol), the sum of the duration of the first signal and the duration of the first level in the second signal is 1 / 2 of the duration of an OFDM symbol, and the number of levels included in the first signal is 6*N*1 / 2-1; the duration of the second signal is inversely proportional to the value of N, and the number of levels included in the second signal is fixed at 4.

[0444] For example, see Fig. 9 , Fig. 9 is another structural diagram of the synchronization signal provided in the embodiment of the present application. Fig. 9 As shown, taking the subcarrier spacing equal to 15kHz as an example, when the duration of the synchronization signal is less than or equal to the duration of 1 (i.e., M=1) OFDM symbol (equivalent to the duration of the synchronization signal being less than or equal to 66.6μs), K=6, X=1 / 2, P2=4, if the first signal is a full {0} signal and the second signal is a signal in which {0} and {1} levels appear alternately, then:

[0445] When N is equal to 1, the number of levels contained in the first signal is 2 (i.e., the first signal is {00}), and the number of levels contained in the second signal is 4 (i.e., the second signal is {0101}). When the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0446] When N is equal to 2, the number of levels contained in the first signal is 5 (that is, the first signal is {00000}), and the number of levels contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 27.7μs, and the duration T2 of the second signal is 22.2μs.

[0447] When N is equal to 3, the number of levels contained in the first signal is 8 (that is, the first signal is {00000000}), and the number of levels contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 29.6μs, and the duration T2 of the second signal is 14.8μs.

[0448] When N is equal to 4, the level contained in the first signal is 11 (that is, the first signal is {00000000000}), and the level number contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T1 of the first signal is 30.5μs, and the duration T2 of the second signal is 11.1μs.

[0449] Depend on Fig. 9 It can be seen that when the subcarrier spacing is equal to 15kHz, before adding CP, the duration of the first signal T1 = 1 / 2*66.6μs-66.6μs / 6*N. In other words, the sum of the duration T1 of the first signal and the duration of a first level in the second signal is a fixed value of 33.3μs. The duration of the second signal is inversely proportional to the value of N. When N is equal to 1, the duration of the second signal is 44.4μs, when N is equal to 2, the duration of the second signal is 22.2μs, when N is equal to 3, the duration of the second signal is 14.8μs, and when N is equal to 4, the duration of the second signal is 11.1μs. The number of levels contained in the first signal is 6*N*1 / 2-1, and the number of levels contained in the second signal is fixed to 4.

[0450] Under mode three, another design is that the synchronization signal includes a first signal, a second signal and a third signal, wherein the duration of the first time domain resource used to transmit the synchronization signal is equal to the duration of M OFDM symbols, or, it is understood that the sum of the durations of the first signal, the second signal and the third signal is equal to the duration of M OFDM symbols.

[0451] Among them, the third signal is before the first signal, that is, the arrangement order of the first signal, the second signal, and the third signal in the synchronization signal is {third signal, first signal, second signal}. Exemplarily, any level included in the third signal can be the second level, that is, the third signal is a full {1} ​​(or full high level) signal, which is conducive to the tag to obtain more energy and maintain normal communication.

[0452] It should be understood that since the sum of the durations of the first signal, the second signal and the third signal is equal to the duration of M OFDM symbols, the duration T3 of the third signal can satisfy: T3 = M*T-T1-T2. Optionally, the number of levels P3 included in the third signal can satisfy: P3 = M*K*N-P1-P2. Wherein, K is the number of levels included in an OFDM symbol when N is equal to 1, and K is a positive integer. Here, M*K*N is the total number of levels included in the synchronization signal. When K is equal to 6 and M is equal to 1, the total number of levels included in the synchronization signal of mode three is 6*N, so the number of levels P3 included in the third signal satisfies: P3 = 6*N-6*N*X-P2.

[0453] For example, see Fig.10 , Fig.10 is another structural diagram of the synchronization signal provided in the embodiment of the present application. Fig.10 As shown, taking the subcarrier spacing of 15kHz as an example, when the duration of the synchronization signal is equal to the duration of 1 (i.e., M=1) OFDM symbol (equivalent to the duration of the synchronization signal being equal to 66.6μs), K=6, X=1 / 2, and P2=4, if the third signal is an all-{1} signal, the first signal is an all-{0} signal, and the second signal is a signal in which {0} and {1} levels appear alternately, then:

[0454] When N is equal to 1, the number of levels included in the third signal is 0 (i.e., there is no third signal), the number of levels included in the first signal is 2 (i.e., the first signal is {00}), and the number of levels included in the second signal is 4 (i.e., the second signal is {0101}). When the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 0μs, the duration T1 of the first signal is 22.2μs, and the duration T2 of the second signal is 44.4μs.

[0455] When N is equal to 2, the number of levels included in the third signal is 3 (that is, the third signal is {111}), the number of levels included in the first signal is 5 (that is, the first signal is {00000}), and the number of levels included in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 16.7μs, the duration T1 of the first signal is 27.7μs, and the duration T2 of the second signal is 22.2μs.

[0456] When N is equal to 3, the number of levels contained in the third signal is 6 (that is, the third signal is {111111}), the number of levels contained in the first signal is 8 (that is, the first signal is {00000000}), and the number of levels contained in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 22.2μs, the duration T1 of the first signal is 29.6μs, and the duration T2 of the second signal is 14.8μs.

[0457] When N is equal to 4, the number of levels included in the third signal is 9 (that is, the third signal is {111111111}), the number of levels included in the first signal is 11 (that is, the first signal is {00000000000}), and the number of levels included in the second signal is 4 (that is, the second signal is {0101}); when the subcarrier spacing is equal to 15kHz, before adding CP, the duration T3 of the third signal is 25μs, the duration T1 of the first signal is 30.5μs, and the duration T2 of the second signal is 11.1μs.

[0458] Depend on Fig.10 It can be seen that when the subcarrier spacing is equal to 15kHz, before adding CP, the duration of the first signal T1 = 1 / 2*66.6μs-66.6μs / 6*N. In other words, the sum of the duration T1 of the first signal and the duration of a first level in the second signal is a fixed value of 33.3μs. The duration of the second signal is inversely proportional to the value of N. When N is equal to 1, the duration of the second signal is 44.4μs, when N is equal to 2, the duration of the second signal is 22.2μs, when N is equal to 3, the duration of the second signal is 14.8μs, and when N is equal to 4, the duration of the second signal is 11.1μs. The duration of the third signal T3 = 66.6μs-T1-T2. The number of levels contained in the first signal is 6*N*1 / 2-1, the number of levels contained in the second signal is fixed to 4, and the number of levels contained in the third signal P3 = 6*N-(6*N*1 / 2-1)-4.

[0459] Optionally, in this application, the network device may specifically adopt the following Figure 6The DFT-S-OFDM generation mode shown processes the synchronization signal and then sends it, wherein the length of the DFT input sequence is N*12, the pattern of the DFT input sequence is the third signal, and the first signal and the second signal contain all levels, each of which is repeated a number of times equal to 12 / K, and for example, when K is equal to 6, the number of repetitions is equal to 2. Exemplarily, when the duration of the synchronization signal is 1 OFDM symbol (i.e., M=1), when N is equal to 2, the third signal contains a level of {111}, the first signal contains a level of {00000}, and the second signal contains a level of {0101}. By repeating each level in the third signal, the first signal, and the second signal by one time (i.e., the number of repetitions of each level is equal to 2), the levels {111111}, {0000000000}, and {00110011} can be obtained, that is, the DFT input sequence is {111111000000000000110011}.

[0460] Based on the design of method three, the performance of the synchronization signal in the passive Internet of Things system can be effectively guaranteed, wherein the duration of the first signal + the duration of the first level of the second signal remain unchanged under different bandwidths, and are not shorter than the duration of the passive tag delimiter (for example, the delimiter duration is not less than 12.5μs). Therefore, the first level of the first signal + the second signal here is equivalent to the delimiter signal, which can effectively guarantee the buffer time for data reception when the tag is started. The number of levels contained in the second signal is fixed to 4, which effectively guarantees the number of levels that can be used when the tag performs clock calibration, while maximizing the transmission peak rate of the (passive or semi-passive) tag as much as possible.

[0461] The embodiment of the present application is compatible with the design of synchronization signals for passive tags under different downlink signal bandwidths, which is beneficial to improving communication performance. In addition, the design of synchronization signals for passive tags in the present application can also adapt to Manchester encoding, that is, the high and low level durations of bit 0 and bit 1 remain equal, which is beneficial to improving demodulation performance.

[0462] The following will be combined Figure 11-12 The communication device provided in this application is described in detail.

[0463] It is understandable that in order to implement the functions in the above embodiments, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0464] Fig.11 and Fig.12 A schematic diagram of the structure of possible communication devices provided for embodiments of the present application. These communication devices can be used to implement the functions of the network device or (passive or semi-passive) tag in the above method embodiment, and therefore can also achieve the beneficial effects possessed by the above method embodiment. In an embodiment of the present application, these communication devices can be network devices or (passive or semi-passive) tags, or can be components or devices (such as processors, chips, or chip systems, etc.) applied to network devices or (passive or semi-passive) tags, or can be logic modules or software that can implement all or part of the network device or (passive or semi-passive) tag functions.

[0465] like Fig.11 As shown, the communication device 1100 includes a processing unit 1110 and a transceiver unit 1120. The communication device 1100 is used to implement the above Figure 4 The method embodiments shown in FIG. 1 are functions of a network device or a (passive or semi-passive) tag.

[0466] When the communication device 1100 is used to implement Figure 4 The functions of the network device in the method embodiment shown are:

[0467] In one design:

[0468] The processing unit 1110 is configured to determine a synchronization signal;

[0469] The transceiver unit 1120 is configured to send the synchronization signal on a first time domain resource and a first frequency domain resource, where the first time domain resource includes M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where both M and N are positive integers;

[0470] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of the T1 and the T2 is equal to the duration of the M OFDM symbols.

[0471] In a possible design, any level included in the first signal is a first level.

[0472] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0473] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0474] In one possible design, the duration of one OFDM symbol is T;

[0475] The duration T1 of the first signal satisfies:

[0476] T1 = M*T*X;

[0477] The duration T2 of the second signal satisfies:

[0478] T2 = M*T*(1-X);

[0479] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0480] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N, and the number P2 of levels included in the second signal is proportional to the value of N.

[0481] In one possible design, the number P1 of levels included in the first signal satisfies:

[0482] P1 = M*K*N*X;

[0483] The number P2 of levels included in the second signal satisfies:

[0484] P2=M*K*N*(1-X);

[0485] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0486] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0487] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0488] In another design:

[0489] The processing unit 1110 is configured to determine a synchronization signal;

[0490] The transceiver unit 1120 is configured to send the synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers;

[0491] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

[0492] In a possible design, any level included in the first signal is a first level.

[0493] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0494] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0495] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0496] In one possible design, the duration of one OFDM symbol is T;

[0497] The duration T1 of the first signal satisfies:

[0498] T1 = M*T*X;

[0499] The duration T2 of the second signal satisfies:

[0500] T2=M*T*(1-X) / N;

[0501] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0502] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N.

[0503] In one possible design, the number P1 of levels included in the first signal satisfies:

[0504] P1 = M*K*N*X;

[0505] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0506] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0507] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0508] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0509] The duration T3 of the third signal satisfies:

[0510] T3 = M*T - T1 - T2;

[0511] The number P3 of levels included in the third signal satisfies:

[0512] P3 = M*K*N - P1 - P2;

[0513] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0514] In one possible design, P2 is equal to 4.

[0515] In yet another design:

[0516] The processing unit 1110 is configured to determine a synchronization signal;

[0517] The transceiver unit 1120 is configured to send the synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N×12 subcarriers, and both M and N are positive integers;

[0518] Among them, the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, and the number P2 of levels included in the second signal is a fixed value.

[0519] In a possible design, any level included in the first signal is a first level.

[0520] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0521] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0522] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0523] In one possible design, the duration of one OFDM symbol is T;

[0524] The duration T1 of the first signal satisfies:

[0525] T1=M*T*X-M*T / K*N;

[0526] The duration T2 of the second signal satisfies:

[0527] T2=M*T*(1-X) / N;

[0528] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0529] In a possible design, the sum of the number P1 of levels included in the first signal and 1 is proportional to the value of N.

[0530] In one possible design, the number P1 of levels included in the first signal satisfies:

[0531] P1=M*K*N*X-1;

[0532] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0533] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0534] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0535] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0536] The duration T3 of the third signal satisfies:

[0537] T3 = M*T - T1 - T2;

[0538] The number P3 of levels included in the third signal satisfies:

[0539] P3 = M*K*N - P1 - P2;

[0540] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0541] In one possible design, P2 is equal to 4.

[0542] When the communication device 1100 is used to implement Figure 4 In the method embodiment shown, the (passive or semi-passive) tag functions as follows:

[0543] In one design:

[0544] The transceiver unit 1120 is configured to receive a synchronization signal on a first time domain resource and a first frequency domain resource, where the first time domain resource includes M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where both M and N are positive integers;

[0545] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of T1 and T2 is equal to the duration of the M OFDM symbols.

[0546] The processing unit 1110 is configured to parse the synchronization signal.

[0547] In a possible design, any level included in the first signal is a first level.

[0548] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0549] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0550] In one possible design, the duration of one OFDM symbol is T;

[0551] The duration T1 of the first signal satisfies:

[0552] T1 = M*T*X;

[0553] The duration T2 of the second signal satisfies:

[0554] T2 = M*T*(1-X);

[0555] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0556] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N, and the number P2 of levels included in the second signal is proportional to the value of N.

[0557] In one possible design, the number P1 of levels included in the first signal satisfies:

[0558] P1 = M*K*N*X;

[0559] The number P2 of levels included in the second signal satisfies:

[0560] P2=M*K*N*(1-X);

[0561] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0562] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0563] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0564] In another design:

[0565] The transceiver unit 1120 is configured to receive a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N*12 subcarriers, where M and N are both positive integers;

[0566] Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

[0567] The processing unit 1110 is configured to parse the synchronization signal.

[0568] In a possible design, any level included in the first signal is a first level.

[0569] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0570] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0571] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0572] In one possible design, the duration of one OFDM symbol is T;

[0573] The duration T1 of the first signal satisfies:

[0574] T1 = M*T*X;

[0575] The duration T2 of the second signal satisfies:

[0576] T2=M*T*(1-X) / N;

[0577] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0578] In a possible design, the number P1 of levels included in the first signal is proportional to the value of N.

[0579] In one possible design, the number P1 of levels included in the first signal satisfies:

[0580] P1 = M*K*N*X;

[0581] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0582] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0583] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0584] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0585] The duration T3 of the third signal satisfies:

[0586] T3 = M*T - T1 - T2;

[0587] The number P3 of levels included in the third signal satisfies:

[0588] P3 = M*K*N - P1 - P2;

[0589] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

[0590] In one possible design, P2 is equal to 4.

[0591] In yet another design:

[0592] The transceiver unit 1120 is configured to receive a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, and the first frequency domain resource includes N×12 subcarriers, where M and N are both positive integers;

[0593] Among them, the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal includes a first signal and a second signal, the first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the sum of the duration T1 of the first signal and the duration of the first level in the second signal is a fixed value, and the number P2 of levels included in the second signal is a fixed value.

[0594] The processing unit 1110 is configured to parse the synchronization signal.

[0595] In a possible design, any level included in the first signal is a first level.

[0596] In one possible design, the second signal includes at least one first level and at least one second level, and the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

[0597] In a possible design, any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

[0598] In one possible design, the duration T2 of the second signal is inversely proportional to the value of N.

[0599] In one possible design, the duration of one OFDM symbol is T;

[0600] The duration T1 of the first signal satisfies:

[0601] T1=M*T*X-M*T / K*N;

[0602] The duration T2 of the second signal satisfies:

[0603] T2=M*T*(1-X) / N;

[0604] Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

[0605] In a possible design, the sum of the number P1 of levels included in the first signal and 1 is proportional to the value of N.

[0606] In one possible design, the number P1 of levels included in the first signal satisfies:

[0607] P1=M*K*N*X-1;

[0608] Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

[0609] In one possible design, when K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

[0610] In a possible design, when M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

[0611] In a possible design, the duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein:

[0612] The duration T3 of the third signal satisfies:

[0613] T3 = M*T - T1 - T2;

[0614] The number P3 of levels included in the third signal satisfies:

[0615] P3 = M*K*N - P1 - P2;

[0616] Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer. In a possible design, P2 is equal to 4.

[0617] For other possible implementations of the communication device, see the above Figure 4 The relevant description of the functions of the relevant equipment in the corresponding method embodiment will not be repeated here.

[0618] like Fig.12 As shown, the communication device 1200 includes a processor 1210 and an interface circuit 1220. The processor 1210 and the interface circuit 1220 are coupled to each other. It is understood that the interface circuit 1220 can be a transceiver or an input-output interface. Optionally, the communication device may further include a memory 1230 for storing instructions executed by the processor 1210 or storing input data required by the processor 1210 to execute instructions or storing data generated after the processor 1210 executes instructions.

[0619] When the communication device is used to implement the method in the above method embodiment, the processor 1210 is used to execute the function of the above processing unit 1110, and the interface circuit 1220 is used to execute the function of the above transceiver unit 1120.

[0620] When the communication device is a chip applied to a network device, the chip implements the function of the network device in the above method embodiment. The chip receives information from other devices; or the network device chip sends information to other devices.

[0621] When the above-mentioned communication device is a chip applied to a (passive or semi-passive) tag, the (passive or semi-passive) tag chip implements the function of the (passive or semi-passive) tag in the above-mentioned method embodiment, and the (passive or semi-passive) tag chip receives information from other devices; or, the (passive or semi-passive) tag chip sends information to other devices.

[0622] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0623] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a network device or a (passive or semi-passive) tag. Of course, the processor and the storage medium can also be present in a network device or a (passive or semi-passive) tag as discrete components.

[0624] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program or instruction can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a digital versatile disc (DVD); it can also be a semiconductor medium, such as a solid state drive (SSD).

[0625] In the various embodiments of the present application, unless otherwise specified or provided in a logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0626] It is understood that the various numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic.

[0627] An embodiment of the present application also provides a computer-readable storage medium, in which computer execution instructions are stored. When the computer execution instructions are executed, the method executed by the network device or (passive or semi-passive) tag in the above method embodiment is implemented.

[0628] An embodiment of the present application also provides a computer program product, which includes a computer program. When the computer program is executed, the method executed by the network device or (passive or semi-passive) tag in the above method embodiment is implemented.

[0629] The present application also provides a communication system, which includes a network device and a (passive or semi-passive) tag. The network device is used to execute the method executed by the network device in the above method embodiment. The (passive or semi-passive) tag is used to execute the method executed by the (passive or semi-passive) tag in the above method embodiment.

[0630] The present application also provides a communication method, wherein the network device is used to execute the method executed by the network device in the above method embodiment. The (passive or semi-passive) tag is used to execute the method executed by the (passive or semi-passive) tag in the above method embodiment.

[0631] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0632] The descriptions of the various embodiments provided in this application can refer to each other, and the descriptions of the various embodiments have their own emphasis. For parts that are not described in detail in a certain embodiment, refer to the relevant descriptions of other embodiments. For the convenience and simplicity of description, for example, the functions of the various devices and equipment provided in the embodiments of this application and the steps of execution can refer to the relevant descriptions of the method embodiments of this application, and the various method embodiments and the various device embodiments can also refer to, combine or quote each other.

[0633] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A communication method, characterized in that: include: determining a synchronization signal; Sending the synchronization signal on a first time domain resource and a first frequency domain resource, the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers; Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

2. The method according to claim 1, characterized in that Any level included in the first signal is a first level.

3. The method according to claim 1 or 2, characterized in that: The second signal includes at least one first level and at least one second level, the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

4. The method according to any one of claims 1 to 3, characterized in that: Any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

5. The method according to any one of claims 1 to 4, characterized in that: The duration T2 of the second signal is inversely proportional to the value of N.

6. The method according to any one of claims 1 to 5, characterized in that: The duration of one OFDM symbol is T; The duration T1 of the first signal satisfies: T1 = M*T*X; The duration T2 of the second signal satisfies: T2=M*T*(1-X) / N; Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

7. The method according to any one of claims 1 to 5, characterized in that: The number P1 of levels included in the first signal is proportional to the value of N.

8. The method according to any one of claims 1 to 7, characterized in that: The number P1 of levels included in the first signal satisfies: P1 = M*K*N*X; Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

9. The method according to claim 8, characterized in that When K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

10. The method according to claim 8 or 9, characterized in that: When M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

11. The method according to any one of claims 1 to 10, characterized in that: The duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein: The duration T3 of the third signal satisfies: T3 = M*T - T1 - T2; The number P3 of levels included in the third signal satisfies: P3 = M*K*N - P1 - P2; Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

12. The method according to any one of claims 1 to 11, characterized in that: The P2 is equal to 4.

13. A communication method, characterized in that: include: Receiving a synchronization signal on a first time domain resource and a first frequency domain resource, wherein the duration of the first time domain resource is less than or equal to the duration of M orthogonal frequency division multiplexing OFDM symbols, the first frequency domain resource includes N*12 subcarriers, and both M and N are positive integers; Among them, the modulation method of the synchronization signal is on-off keying (OOK), and the synchronization signal includes a first signal and a second signal. The first signal indicates that the second signal is after the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the number P2 of levels included in the second signal are both fixed values.

14. The method according to claim 13, characterized in that Any level included in the first signal is a first level.

15. The method according to claim 13 or 14, characterized in that The second signal includes at least one first level and at least one second level, the number of the first levels included in the second signal is equal to the number of the second levels, the second level is higher than the first level, and the duration of the second level is equal to the duration of the first level.

16. The method according to any one of claims 13 to 15, characterized in that: Any adjacent level of the first level included in the second signal is the second level, any adjacent level of the second level included in the second signal is the first level, and the second level is higher than the first level.

17. The method according to any one of claims 13 to 16, characterized in that: The duration T2 of the second signal is inversely proportional to the value of N.

18. The method according to any one of claims 13 to 17, characterized in that: The duration of one OFDM symbol is T; The duration T1 of the first signal satisfies: T1 = M*T*X; The duration T2 of the second signal satisfies: T2=M*T*(1-X) / N; Wherein, 0<X<1; when M=1, the value of X is associated with the subcarrier spacing.

19. The method according to any one of claims 13 to 17, characterized in that: The number P1 of levels included in the first signal is proportional to the value of N.

20. The method according to any one of claims 13 to 19, characterized in that: The number P1 of levels included in the first signal satisfies: P1 = M*K*N*X; Wherein, 0<X<1; the K is the number of levels included in one OFDM symbol when the N is equal to 1, and the K is a positive integer.

21. The method according to claim 20, characterized in that When K is equal to 6, the number P1 of levels included in the first signal is an integer not less than 2, and the number P2 of levels included in the second signal is an integer not less than 2 or an integer not less than 4.

22. The method according to claim 20 or 21, characterized in that When M is equal to 1 and K is equal to 6, X is 1 / 3 or 1 / 2.

23. The method according to any one of claims 13 to 22, characterized in that: The duration of the first time domain resource is equal to the duration of the M OFDM symbols; the synchronization signal further includes a third signal, the third signal is before the first signal, and any level included in the third signal is the second level; wherein: The duration T3 of the third signal satisfies: T3 = M*T - T1 - T2; The number P3 of levels included in the third signal satisfies: P3 = M*K*N - P1 - P2; Wherein, K is the number of levels included in one OFDM symbol when N is equal to 1, and K is a positive integer.

24. The method according to any one of claims 13 to 23, characterized in that: The P2 is equal to 4.

25. A communication device, comprising a unit or module for executing the method according to any one of claims 1 to 12, or comprising a unit or module for executing the method according to any one of claims 13 to 24.

26. A communication device, characterized in that: The device comprises a processor and a transceiver, wherein the processor and the transceiver are used to implement the method according to any one of claims 1 to 12, or to implement the method according to any one of claims 13 to 24.

27. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or an instruction. When the computer program or the instruction is executed by the communication device, the method according to any one of claims 1 to 12 is implemented, or the method according to any one of claims 13 to 24 is implemented.

28. A computer program product, characterized in that The method comprises a computer program code, and when the computer program code is executed on a computer, the method according to any one of claims 1 to 12 is implemented, or the method according to any one of claims 13 to 24 is implemented.

29. A communication system, characterized in that: A communication device comprising a method according to any one of claims 1 to 12, and a communication device comprising a method according to any one of claims 13 to 24.

30. A communication method, characterized in that: The network device is used to execute the method described in any one of claims 1-12, and the tag is used to execute the method described in any one of claims 13-24.

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