Communication method and apparatus, and storage medium and computer program product

Abstract

A communication method and an apparatus, and a storage medium and a computer program product, which relate to the field of communications, and are used for improving the communication performance. The method comprises: on the basis of a value M representing the number of chips in an OFDM symbol in a first signal, a network apparatus selecting a corresponding implementation mode for the first signal, and sending the first signal to a terminal apparatus, wherein when M is greater than or equal to a first threshold, levels of the last X chips of a first OFDM symbol in the first signal are each the same as the level of the first chip in the first OFDM symbol, or are each the same as the level of the last chip of a previous OFDM symbol of the first OFDM symbol, or the level of each of the X chips is ON or OFF; and when M is less than the first threshold, M chips in a second OFDM symbol in the first signal are used for carrying a clock acquisition signal and / or a PRDCH. Therefore, both the signal transmission performance and the signal transmission efficiency in each M value interval can be taken into account, thereby improving the communication performance.

Description

A communication method, apparatus, storage medium, and computer program product

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510404384.1, filed on March 28, 2025, entitled "A Communication Method, Apparatus, Storage Medium and Computer Program Product", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method, device, storage medium, and computer program product. Background Technology

[0004] In the field of communications, devices can transmit signals using ultra-high frequency (UHF) radio frequency identification (RFID) protocols. For example, this is the signal transmission between devices in an ambient IoT (A-IoT) system. Since A-IoT systems are asynchronous, the network side can send a start indication and a clock capture portion to the A-IoT device before sending data signals. The A-IoT device can then synchronize with the network side based on these start indication and clock capture portions before receiving data signals from the network.

[0005] To improve communication performance, a cyclic prefix (CP) is introduced into the signals transmitted between devices. However, the introduction of CP can introduce sudden rising or falling edges into the signal. These sudden rising or falling edges can cause false detections during device testing, leading to a degraded communication performance. Therefore, a solution is urgently needed to improve communication performance. Summary of the Invention

[0006] This application provides a communication method, apparatus, storage medium, and computer program product for improving communication performance.

[0007] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0008] Firstly, a communication method is provided that can be applied to a transmitting device. Unless otherwise specified in this application, the transmitting device may be the transmitting device itself, or a component within the transmitting device (e.g., a module, communication module, circuitry or chip responsible for communication functions (e.g., a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip or system-in-package (SIP) chip containing a modem core), or a logical node, logical module, or software capable of implementing the device's functions. As an example, the transmitting device is a network device, which may be a network device or a component within that network device (e.g., a module, communication module, circuitry or chip responsible for communication functions (e.g., a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core), or a logical node, logical module, or software capable of implementing the device's functions. For example, the network device may include a central unit (CU), a distributed unit (DU), or a radio unit). (unit, RU). For ease of description, the following example assumes the sending device is a network device. Optionally, the network device is a card reader or a reader-writer, or the network device has the function of a card reader or a reader-writer.

[0009] The method includes: a network device determining a first signal and transmitting the first signal. The first signal includes K orthogonal frequency division multiplexing (OFDM) symbols, where K is a positive integer, and each OFDM symbol includes M chips, where M is a positive integer.

[0010] Where M is greater than or equal to the first threshold, the K OFDM symbols include the first OFDM symbol. K > 1 or K = 1. The following K > 1 and K = 1 can each correspond to two implementation methods, and at least one of these two implementation methods can be satisfied.

[0011] Where K > 1 (or in the case of K > 1): the level of the last X chips of the first OFDM symbol is the same as the level of the first chip in the first OFDM symbol, or the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the preceding OFDM symbol; or the level of each of the last X chips of the first OFDM symbol is either ON or OFF. In this embodiment, an ON level can be understood as on or open, or as a high level. An OFF level can be understood as off or closed, or as a low level. Alternatively, the level can be replaced with "OOK symbol", ON can be replaced with OOK symbol 1, and OFF can be replaced with OOK symbol 0.

[0012] Alternatively, K=1 (or in the case of K=1): the level of the last X chips of the first OFDM symbol is the same as the level of the first chip of the first OFDM symbol, or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF.

[0013] In this embodiment, X is a positive integer, and the last X chips of the first OFDM symbol are padding chips. In one possible implementation, the last X chips of the first OFDM symbol being padding chips can include / be replaced / understood as follows: the last X chips of the first OFDM symbol are padding chips, and the padding chips are not used to carry the clock acquisition part (CAP) and / or the physical reader device channel (PRDCH), or the padding chips are not used to carry the bits of CAP and / or PRDCH, or the padding chips are not used in carrying the data of CAP and / or PRDCH.

[0014] When M is less than a first threshold, the K OFDM symbols include a second OFDM symbol, and M chips in the second OFDM symbol are used to carry the clock capture portion and / or PRDCH. In one possible implementation, the M chips in the second OFDM symbol used to carry the clock capture portion and / or PRDCH may include / be replaced by: the second OFDM symbol does not include padding chips. In another possible implementation, the chip carrying PRDCH in the embodiments of this application may include / be replaced by: the chip carrying the data signal (or data information) in the PRDCH, and the chip carrying the bits in the PRDCH.

[0015] For ease of explanation, the implementation method satisfied by the first OFDM symbol above can be referred to as implementation method A1, and the implementation method satisfied by the second OFDM symbol above can be referred to as implementation method A2.

[0016] In implementation A1, the last X chips of the first OFDM symbol in the K OFDM symbols of the first signal can be filler chips. When the network device adds a CP to the first signal, it can copy the last X chips of the first OFDM symbol before the first OFDM symbol as the CP. Since the level of these X chips is the same as the level of the first chip in the first OFDM symbol, or the level of these X chips is the same as the level of the last chip of the OFDM symbol preceding the first OFDM symbol, the newly added CP has the same level as the first chip in the first OFDM symbol, or the same level as the last chip of the OFDM symbol preceding the first OFDM symbol. Therefore, the added CP portion will not contain any edges (e.g., rising and / or falling edges), meaning that adding a CP will not cause new edges in the signal. The subsequent terminal device can perform a CP removal operation on the received first signal, thereby reducing the interference of the CP on decoding performance, reducing the false detection rate at the receiving end, and improving communication performance.

[0017] Alternatively, in implementation A1, the voltage level of each of the X chips is either ON or OFF. When the network device copies one or more chips from the first OFDM symbol to the beginning of the first OFDM symbol as a CP (Clipped Component), there will be no edges in the copied chips. The subsequent terminal device can then perform CP removal on the received first signal, thereby reducing the interference of CP on decoding performance, lowering the false detection rate at the receiver, and improving communication performance.

[0018] However, in the above implementation A1, when M is a small value (e.g., less than the first threshold), the duration occupied by a single chip is relatively long, resulting in a large amount of time-domain resources being occupied by X chips. Since these X chips are filler chips (e.g., these X chips do not carry the clock capture portion and PRDCH), the data transmission efficiency is relatively low. For example, when M is 4 and X is 2, the length of each chip is relatively long, which may result in a 50% loss in transmission efficiency.

[0019] In implementation A2, the K OFDM symbols include a second OFDM symbol, and M chips in the second OFDM symbol are used to carry the clock acquisition section and / or PRDCH. That is, the second OFDM symbol may not include padding chips. The terminal device can use the last edge within the OFDM symbol as a reference time to find the position of the CP and remove the sampling points contained in the CP, thereby reducing the interference of the CP on decoding performance, thereby reducing the false detection rate at the receiver and improving communication performance.

[0020] However, in the above implementation A2, when M is a large value (e.g., greater than or equal to the first threshold), the duration occupied by a CP may be greater than the duration occupied by a chip. Therefore, the network device may need to copy multiple chips from the first OFDM symbol before the first OFDM symbol as CPs. The edges of these multiple chips may also be copied before the first OFDM symbol as CPs, resulting in edges existing in the CP. Due to clock errors, the terminal device may not be able to accurately remove the CP when performing the CP removal operation, causing the edges existing in the CP to be left in the signal, becoming false edges in the signal, thus causing errors in the decoding process of the terminal device.

[0021] The above analysis shows that, in order to reduce the impact of CP on decoding, both implementation schemes A1 and A2 have advantages and disadvantages. To further improve communication performance, this application provides an implementation scheme in which the network device can flexibly select the implementation scheme based on the value of M. For example, when M is greater than or equal to a first threshold, the network device can choose to use implementation scheme A1, thus reducing the interference of CP on decoding performance, thereby reducing the false positive rate during receiver detection and improving communication performance. Alternatively, when M is less than the first threshold, the network device can choose to use implementation scheme A2. This reduces the interference of CP on decoding performance, thereby reducing the false positive rate during receiver detection, and also improves data transmission efficiency. It can be seen that this implementation scheme, which flexibly selects the implementation scheme based on the value of M, can balance the false positive rate during receiver detection and transmission efficiency, thereby improving overall communication performance.

[0022] In the above embodiments, the case where M equals the first threshold can be flexibly set. For example, when M equals the first threshold, the network device can also execute the above embodiment A2. For example, when M is greater than the first threshold, the K OFDM symbols, including the first OFDM symbol, satisfy the following: When K > 1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip in the first OFDM symbol, or the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the preceding OFDM symbol; or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF; When K = 1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip of the first OFDM symbol, or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF. When M is less than or equal to the first threshold, the K OFDM symbols include a second OFDM symbol, and the M chips in the second OFDM symbol are used to carry the clock capture section and / or PRDCH. The rest can be found in the aforementioned scheme and will not be repeated here.

[0023] One possible implementation is to add a CP to each of the K OFDM symbols. This can mitigate inter-symbol interference caused by multipath delay and also enable time boundary alignment of the next time slot after the symbols are combined into a time slot.

[0024] In one possible implementation, the first OFDM symbol is any one of the K OFDM symbols. Thus, each of the K OFDM symbols can execute the aforementioned scheme for the first OFDM symbol, thereby reducing the interference of the CP added to each of the K OFDM symbols on decoding performance, thereby lowering the false detection rate and improving communication performance.

[0025] In another possible implementation, the first OFDM symbol is any one of the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion. Thus, each of the remaining OFDM symbols, except those carrying the start indication portion, can execute the aforementioned scheme for the first OFDM symbol. This reduces the interference of the CP added to each of the K OFDM symbols on decoding performance, thereby lowering the false detection rate and improving communication performance.

[0026] In another possible implementation, the first OFDM symbol is the first OFDM symbol among the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion. For example, the K OFDM symbols in the time domain sequentially include OFDM symbol #11, OFDM symbol #12, and OFDM symbol #13. If S is 1, then the S OFDM symbols are OFDM symbol #11, and the OFDM symbols excluding the first S OFDM symbols are OFDM symbol #12 and OFDM symbol #13. The first OFDM symbol among the OFDM symbols excluding the first S OFDM symbols is OFDM symbol #12. Furthermore, the implementation of the remaining OFDM symbols excluding the first S OFDM symbols and the first OFDM symbol is not restricted, thereby increasing the flexibility of the scheme.

[0027] In one possible implementation, the time length occupied by the X chips is related to the time length occupied by the CP (Concurrent Component). This allows for setting reasonable values ​​for X, thereby further improving communication performance. For example, the time length occupied by the X chips is greater than or equal to the time length occupied by the CP. Thus, when the network device performs the operation of adding a CP, it can copy all or part of the levels from the X chips to the beginning of the first OFDM symbol as the CP, thereby avoiding copying chips outside the X chips as the CP. This further avoids the generation of edges (rising and / or falling edges) in the CP, thereby further reducing the interference of the CP on decoding performance, reducing the false positive rate during receiver detection, and thus improving communication performance.

[0028] For example, when M is 32, X is 3. Or, when M is 12, 16, or 24, X is 2. Or, when M is 6, 8, or 12, X is 1. These examples allow the time length occupied by the X chips to be greater than or equal to the time length occupied by the CP. Therefore, when the network device performs the CP addition operation, it can copy all or part of the levels from the X chips to the beginning of the first OFDM symbol as the CP. This avoids copying chips outside the X chips as the CP, further avoiding the generation of edges (rising and / or falling edges) in the CP, thus further reducing the interference of the CP on decoding performance, thereby reducing the false detection rate at the receiver and improving communication performance.

[0029] In one possible implementation, when X is odd, the voltage level of the preceding adjacent chip of the first OFDM symbol's X chips is opposite to the voltage levels of the X chips, and the preceding chip of the first OFDM symbol's X chips is a padding chip. Since the preceding chip of the first OFDM symbol is also used as a padding chip when X is odd, and the voltage level of this preceding chip can be the same as or opposite to the voltage levels of the X chips, the duration of the ON or OFF voltage level at the tail of the first OFDM symbol will not be too long, thereby reducing the bit error rate and improving communication performance.

[0030] In one possible implementation, the first threshold is associated with the signal carried by a chip in a first OFDM symbol. The first OFDM symbol includes chips for carrying a clock capture portion and chips for carrying a PRDCH. Alternatively, the first OFDM symbol may include chips for carrying a PRDCH (e.g., the first OFDM symbol may not include chips for carrying a clock capture portion; or, for example, the first OFDM symbol may only include chips for carrying a PRDCH). This allows for setting a reasonable first threshold, thereby reducing interference from CP under different conditions. For example, the value of the first threshold is lower when the first OFDM symbol includes chips for carrying a clock capture portion than when the first OFDM symbol does not include chips for carrying a clock capture portion and only includes chips for carrying a PRDCH. For example, when the first OFDM symbol includes chips for carrying a clock capture portion, the first threshold is set to 6. For example, when the first OFDM symbol does not include chips for carrying a clock capture portion and only includes chips for carrying a PRDCH, the first threshold is set to 8 or 12. These implementations allow for a more reasonable setting of the first threshold.

[0031] In one possible implementation, the first threshold is 6, 8, 12, 16, or 24. For example, if the first OFDM symbol includes a chip for carrying the PRDCH but does not include a chip for carrying the clock capture portion, the first threshold is 6, 8, 12, 16, or 24.

[0032] Secondly, a communication method is provided that can be applied to a transmitting device. Unless otherwise specified in this application, the transmitting device may be the transmitting device itself, or a component within the transmitting device (e.g., a module, communication module, circuit or chip responsible for communication functions (e.g., a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core), or a logical node, logical module, or software that implements the device's functions. As an example, the transmitting device may be a network device, which can be a network device or a component within that network device (e.g., a module, communication module, circuit or chip responsible for communication functions (e.g., a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core), or a logical node, logical module, or software that implements the device's functions. For example, the network device includes a CU, DU, or RU. For ease of description, the following example uses a network device as the transmitting device. Optionally, the network device may be a card reader or a card reader / writer, or the network device may have the functions of a card reader or a card reader / writer.

[0033] The method includes: a network device determining a first signal and transmitting the first signal, the first signal including K OFDM symbols, where K is a positive integer, and each of the K OFDM symbols including M chips, where M is a positive integer.

[0034] Where M is greater than or equal to the first threshold, the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is P. P < M, P is an odd number, and P is a positive integer. The number of chips used to carry the PRDCH in the OFDM symbols other than the first OFDM symbol out of the K OFDM symbols is M. In this embodiment, K is a positive integer, and K can be 1 or an integer greater than 1. When K is 1, the number of chips used to carry the PRDCH in the OFDM symbols other than the first OFDM symbol out of the K OFDM symbols, M can be included / understood / replaced as: the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is P, and there are no other OFDM symbols other than the first OFDM symbol out of the K OFDM symbols. When K is an integer greater than 1, the number of chips used to carry PRDCH in the K OFDM symbols excluding the first OFDM symbol is M. This can be included / understood / replaced as: the number of chips used to carry PRDCH in the first OFDM symbol of the K OFDM symbols is P, and the number of chips used to carry PRDCH in the remaining OFDM symbols is M.

[0035] When M is less than the first threshold, the number of chips used to carry the PRDCH in the first OFDM symbol out of K OFDM symbols is N. N≤M, and N is an even number. The number of chips used to carry the PRDCH in all K OFDM symbols except the first OFDM symbol is M.

[0036] For ease of explanation, the implementation where the number of chips used to carry the PRDCH in the first OFDM symbol of the K OFDM symbols mentioned above is P can be called implementation B1, and the implementation where the number of chips used to carry the PRDCH in the first OFDM symbol of the K OFDM symbols mentioned above is N can be called implementation B2.

[0037] In implementation B1, the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is odd. Therefore, when the network device adds a CP to the first signal, it can add the CP at the edge (rising edge or falling edge) of the signal. In this case, regardless of whether the level of the chip copied by the network device is high, low, or includes an edge portion, that portion of the level will not have an additional edge added. That is, in this scheme, adding a CP will not result in an additional edge. Subsequently, the terminal device can perform a CP removal operation on the received first signal, thereby reducing the interference of the CP on the decoding performance, thereby reducing the false detection rate at the receiver and improving communication performance.

[0038] However, in the above implementation B1, when M is a small value (e.g., less than the first threshold), the length of a chip is relatively long, and the edge of the OFDM symbol is located in the time portion occupied by the CP. This edge may be at the beginning or end of the CP. Therefore, when the terminal device detects, the position of the edge in the time portion occupied by the CP is uncertain, and the terminal device may make a misjudgment, which will lead to a decrease in communication performance.

[0039] In implementation B2, the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is even. The terminal device can use the last edge within the OFDM symbol as a reference time to find the position of the CP and remove the sampling points contained in the CP, thereby reducing the interference of the CP on the decoding performance, thereby reducing the false detection rate at the receiver and improving communication performance.

[0040] In the above implementation B2, when M is a large value (e.g., greater than or equal to the first threshold), the duration occupied by a CP may be greater than the duration occupied by a chip. Therefore, the network device may need to copy multiple chips from an OFDM symbol before the OFDM symbol as CPs. The edges of these multiple chips may also be copied before the OFDM symbol as CPs, resulting in edges within the CP. Due to clock errors, the terminal device may not be able to accurately remove the CP when performing the CP removal operation, causing the edges present in the CP to remain in the signal, becoming false edges in the signal, leading to errors in the decoding process.

[0041] The above analysis shows that, in order to reduce the impact of CP on decoding, both implementation methods B1 and B2 have advantages and disadvantages. To further improve communication performance, this application provides an implementation method in which the network device can flexibly select the implementation method based on the value of M. For example, when M is greater than or equal to a first threshold, the network device can choose to use implementation method B1, thus reducing the interference of CP on decoding performance, thereby reducing the false positive rate during receiver detection and improving communication performance. Similarly, when M is less than the first threshold, the network device can choose to use implementation method B2, thereby reducing the false positive rate during receiver detection and improving communication performance. It can be seen that this implementation method, which flexibly selects the implementation method based on the value of M, can balance the false positive rate during receiver detection and transmission efficiency, thereby improving overall communication performance.

[0042] In the above embodiments, the case where M equals the first threshold can be flexibly set. For example, if M equals the first threshold, the network device can also execute the above embodiment B2. For example, if M is greater than the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol out of K OFDM symbols is P, and the number of chips used to carry PRDCH in the other OFDM symbols out of K OFDM symbols is M. If M is less than or equal to the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol out of K OFDM symbols is N, and the number of chips used to carry PRDCH in the other OFDM symbols out of K OFDM symbols is M. The remaining details can be found in the aforementioned scheme and will not be repeated here.

[0043] In one possible implementation, when M is greater than or equal to a first threshold, the first OFDM symbol among the K OFDM symbols further includes a chip for carrying the clock capture portion, and the number of chips for carrying the clock capture portion in the first OFDM symbol among the K OFDM symbols is odd. Since the sum of two odd numbers is even, the number of chips in the first OFDM symbol among the K OFDM symbols can be even, thus satisfying the requirement that M is defined as an even number.

[0044] In one possible implementation, when M is less than a first threshold, the first OFDM symbol among the K OFDM symbols further includes a chip for carrying the clock capture portion, and the number of chips for carrying the clock capture portion in the first OFDM symbol among the K OFDM symbols is even. Since the sum of even numbers is even, the number of chips in the first OFDM symbol among the K OFDM symbols can be even, thus satisfying the requirement that M is defined as an even number.

[0045] In one possible implementation, the first threshold is associated with the signal carried by the packet chip in the K OFDM symbols. The K OFDM symbols include chips for carrying the clock capture portion and chips for carrying the PRDCH. Alternatively, the K OFDM symbols include chips for carrying the PRDCH (e.g., the K OFDM symbols do not include chips for carrying the clock capture portion; or, for example, the K OFDM symbols only include chips for carrying the PRDCH). Related details and beneficial effects can be found in the description of possible implementations of the first aspect above, and will not be repeated here.

[0046] In one possible implementation, the first threshold is 6, 8, 12, 16, or 24. Related details and beneficial effects can be found in the description of possible implementations of the first aspect above, and will not be repeated here.

[0047] Thirdly, a communication method is provided, which can be applied to a receiving device. The receiving device can be a receiving equipment or a component within that receiving equipment (e.g., a module, communication module, circuit or chip responsible for communication functions such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core; it can also be a logic node, logic module, or software that implements the device's functions). For example, the receiving device is a terminal device, which can be a terminal equipment or a component within that terminal equipment (e.g., a module, communication module, circuit or chip responsible for communication functions such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core; it can also be a logic node, logic module, or software that implements the device's functions). For ease of description, the following example uses the method applied to a terminal device. For example, the terminal device is an ambient IoT (A-IoT) device. Another example is a tag.

[0048] The method includes: a terminal device receiving a first signal and detecting the first signal. The first signal includes K OFDM symbols, where K is a positive integer, and each of the K OFDM symbols includes M chips, where M is a positive integer.

[0049] Where M is greater than or equal to the first threshold, the K OFDM symbols include the first OFDM symbol:

[0050] K > 1 (or in the case of K > 1): The level of the last X chips of the first OFDM symbol is the same as the level of the first chip in the first OFDM symbol, or the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the preceding OFDM symbol; or, the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF, where X is a positive integer, and the last X chips of the first OFDM symbol are filler chips;

[0051] Alternatively, K=1 (or in the case of K=1): the level of the last X chips of the first OFDM symbol is the same as the level of the first chip of the first OFDM symbol; or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF.

[0052] When M is less than the first threshold, the K OFDM symbols include a second OFDM symbol, and the M chips in the second OFDM symbol are used to carry the clock capture section and / or PRDCH.

[0053] In another possible implementation, when M equals the first threshold, the K OFDM symbols include a second OFDM symbol, in which M chips are used to carry the clock capture section and / or PRDCH.

[0054] In one possible implementation, after receiving the first signal from the network device, if the terminal device determines that M is greater than or equal to a first threshold, the terminal device can perform a CP (Chip Component Discard) operation. Since the last X chips of the first OFDM symbol are padding chips, the terminal device can also perform a CP discard operation. This reduces the decoding complexity on the terminal device side. In another possible implementation, after receiving the first signal from the network device, if the terminal device determines that M is less than the first threshold, the terminal device can perform a CP discard operation.

[0055] Alternatively, in one possible implementation, after receiving the first signal from the network device, if the terminal device determines that M is greater than a first threshold, the terminal device can perform a CP discarding operation. Since the last X chips of the first OFDM symbol are padding chips, the terminal device can also perform a CP discarding operation. This reduces the decoding complexity on the terminal device side. In yet another possible implementation, after receiving the first signal from the network device, if the terminal device determines that M is less than or equal to the first threshold, the terminal device can perform a CP discarding operation.

[0056] In one possible implementation, the first OFDM symbol is any one of the K OFDM symbols; or, the first OFDM symbol is any one of the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion.

[0057] In another possible implementation, the first OFDM symbol is the first OFDM symbol among the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion.

[0058] In one possible implementation, the time length occupied by X chips is greater than or equal to the time length occupied by CP.

[0059] In one possible implementation, the value of X is 3 when the value of M is 32; or, the value of X is 2 when the value of M is 12, 16, or 24; or, the value of X is 1 when the value of M is 6, 8, or 12.

[0060] In one possible implementation, when the value of X is odd, the level of the preceding adjacent chip of the X chips of the first OFDM symbol is opposite to the level of the X chips, and the preceding chip of the X chips of the first OFDM symbol is a padding chip.

[0061] In one possible implementation, the first threshold is associated with the signal carried by a chip in a first OFDM symbol, the first OFDM symbol including: a chip for carrying a clock capture portion and / or a chip for carrying a PRDCH.

[0062] In one possible implementation, the first threshold is 6, 8, 12, 16, or 24.

[0063] The relevant content and beneficial effects of the third aspect and its possible implementation methods can be found in the foregoing description of the first aspect and its possible implementation methods, and will not be repeated here.

[0064] Fourthly, a communication method is provided, which can be applied to a receiving device. The receiving device can be a receiving equipment or a component within that receiving equipment (e.g., a module, communication module, circuit or chip responsible for communication functions such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core; it can also be a logic node, logic module, or software that implements the device's functions). For example, the receiving device is a terminal device, which can be a terminal equipment or a component within that terminal equipment (e.g., a module, communication module, circuit or chip responsible for communication functions such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core; it can also be a logic node, logic module, or software that implements the device's functions). For ease of description, the following example uses the method applied to a terminal device. For example, the terminal device is an ambient IoT (A-IoT) device. Another example is a tag.

[0065] The method includes: a terminal device receiving a first signal and detecting the first signal. The first signal includes K OFDM symbols, where K is a positive integer, and each of the K OFDM symbols includes M chips, where M is a positive integer.

[0066] Where M is greater than or equal to the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol among the K OFDM symbols is P, P < M, and P is an odd number. The number of chips used to carry PRDCH in the OFDM symbols other than the first OFDM symbol among the K OFDM symbols is M.

[0067] When M is less than the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol among the K OFDM symbols is N, N≤M, and N is an even number. The number of chips used to carry PRDCH in the OFDM symbols other than the first OFDM symbol among the K OFDM symbols is M.

[0068] In another possible implementation, when M equals the first threshold, the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is N, N≤M, where N is an even number, and the number of chips used to carry the PRDCH in the OFDM symbols other than the first OFDM symbol out of the K OFDM symbols is M.

[0069] In one possible implementation, after receiving the first signal from the network device, the terminal device can perform the operation of discarding the CP.

[0070] In one possible implementation, if M is greater than or equal to a first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture section, and the number of chips used to carry the clock capture section in the first OFDM symbol among the K OFDM symbols is odd.

[0071] In one possible implementation, if M is less than a first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture section, and the number of chips used to carry the clock capture section in the first OFDM symbol among the K OFDM symbols is an even number.

[0072] In one possible implementation, the first threshold is associated with the signal carried by the chips in K OFDM symbols, including chips for carrying the clock capture portion and / or chips for carrying the PRDCH.

[0073] In one possible implementation, the first threshold is 6, 8, 12, 16, or 24.

[0074] The relevant content and beneficial effects of the fourth aspect and its possible implementation methods can be found in the description of the second aspect and its possible implementation methods mentioned above, and will not be repeated here.

[0075] Fifthly, a communication device is provided, which can be the aforementioned network device or terminal device. The communication device may include a communication unit and a processing unit to perform any one of the first to fourth aspects, or any possible implementation of the first to fourth aspects. The communication unit is used to perform functions related to sending and receiving. The communication unit may be referred to as a transceiver unit. Optionally, the communication unit includes a receiving unit and a sending unit. In one design, the communication device is a communication chip, the processing unit may be one or more processors or processor cores, and the communication unit may be the input / output circuit, input / output interface, or antenna port of the communication chip.

[0076] In another design, the communication unit can be a transmitter and a receiver, or the communication unit can be a transmitter and a receiver.

[0077] Optionally, the communication device may also include modules that can be used to perform any one of the first to fourth aspects described above, or to perform any possible implementation of the first to fourth aspects.

[0078] Sixthly, a communication device is provided, which can be the aforementioned network device or terminal device. The communication device may include a processor and a memory to execute any one of the first to fourth aspects, or any possible implementation of the first to fourth aspects. Optionally, it may also include a transceiver, the memory for storing computer programs or instructions, and the processor for retrieving and running the computer programs or instructions from the memory. When the processor executes the computer programs or instructions in the memory, the communication device executes any one of the first to fourth aspects, or any possible implementation of the first to fourth aspects.

[0079] Optionally, there may be one or more processors and one or more memories.

[0080] Optionally, the memory can be integrated with the processor, or the memory can be set up separately from the processor.

[0081] Optionally, the transceiver may include a transmitter and a receiver.

[0082] A seventh aspect provides a communication device, which can be the aforementioned network device or terminal device. The communication device may include a processor to execute any one of the first to fourth aspects, or to execute any possible implementation of the first to fourth aspects. For example, the processor executes any one of the first to fourth aspects, or to execute any possible implementation of the first to fourth aspects, through logic circuits or by executing computer programs or instructions in memory. The processor is coupled to a memory. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0083] In one implementation, when the communication device is a network device or a terminal device, the communication interface can be a transceiver or an input / output interface. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0084] In another implementation, when the communication device is a chip or chip system, the communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be manifested as a processing circuit or logic circuit.

[0085] Eighthly, a system is provided that includes a terminal device.

[0086] In one possible implementation, the system may also include a network device.

[0087] In a ninth aspect, a chip system is provided, the chip system including at least one processor and an interface circuit, the interface circuit and the at least one processor being interconnected via a line, the processor executing a computer program (also referred to as code or instructions) to cause any one of the first to fourth aspects and any possible implementation of the first to fourth aspects to be executed.

[0088] In a tenth aspect, a computer program product is provided, comprising: a computer program (also referred to as code or instructions) that, when executed, causes a computer to perform any one of the first to fourth aspects described above, or to perform any possible implementation of the first to fourth aspects.

[0089] Eleventhly, a computer-readable storage medium is provided, which stores a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform any one of the first to fourth aspects described above, or to perform any possible implementation of the first to fourth aspects.

[0090] In a twelfth aspect, a processing apparatus is provided, comprising: an interface circuit and a processing circuit. The interface circuit may include an input circuit and an output circuit. The processing circuit is configured to receive signals through the input circuit and transmit signals through the output circuit, thereby enabling any one of the first to fourth aspects, or any possible implementation thereof, to be carried out.

[0091] In specific implementation, the aforementioned processing device can be a chip, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, gate circuit, flip-flop, and various logic circuits, etc. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as the input circuit and output circuit at different times. This application does not limit the specific implementation method of the processor and various circuits.

[0092] In one implementation, the communication device is a network device or a terminal device. The interface circuit can be an RF processing chip in the network device or terminal device, and the processing circuit can be a baseband processing chip in the network device or terminal device.

[0093] In another implementation, the communication device can be a component within a network device or terminal device, such as an integrated circuit product like a system-on-a-chip (SoC) or communication chip. The interface circuit can be an input / output interface, interface circuit, output circuit, input circuit, pins, or related circuits on the chip or chip system. The processing circuit can be the logic circuit on the chip. Attached Figure Description

[0094] Figure 1 is a possible schematic diagram of a signal transmitted between devices according to an embodiment of this application;

[0095] Figure 2 is a schematic diagram of a possible architecture of a communication system provided in an embodiment of this application;

[0096] Figure 3 is a schematic diagram of the operation of a backscattering system provided in an embodiment of this application;

[0097] Figures 4A and 4B are schematic diagrams of the communication system applicable to the embodiments of this application;

[0098] Figures 5A and 5B are schematic diagrams of the A-IoT structure;

[0099] Figure 6 is a possible schematic diagram of a signal transmitted between devices according to an embodiment of this application;

[0100] Figure 7 is a possible flowchart of another communication method provided in an embodiment of this application;

[0101] Figure 8 is a possible schematic diagram of another first signal provided in an embodiment of this application;

[0102] Figure 9 is a possible schematic diagram of another first signal provided in an embodiment of this application;

[0103] Figure 10 is a possible schematic diagram of another first signal provided in an embodiment of this application;

[0104] Figure 11 is a possible schematic diagram of another first signal provided in an embodiment of this application;

[0105] Figure 12 is a possible schematic diagram of another first signal provided in an embodiment of this application;

[0106] Figure 13 is a schematic diagram of signal-to-noise ratio (SNR) and block error rate (BLER) using various implementation methods provided in the embodiments of this application;

[0107] Figure 14 is a schematic diagram of a communication device provided in an embodiment of this application;

[0108] Figure 15 is a schematic diagram of another structure of the communication device provided in the embodiment of this application. Detailed Implementation

[0109] The following section will introduce the terms and related technologies involved in the embodiments of this application.

[0110] 1. Time-domain unit.

[0111] Temporal resources may include at least one of radio frames, subframes, slots, mini slots, or symbols. Symbols may include, for example, OFDM symbols.

[0112] A time-domain element (TDI) may include a radio frame, a subframe, a slot, a mini-slot, or a symbol. For example, a TDI may include an OFDM symbol. A TDI may also include resources composed of multiple radio frames, multiple subframes, multiple slots, multiple mini-slots, or multiple OFDM symbols. A radio frame may include multiple subframes, a subframe may include one or more slots, and a slot may include at least one symbol. Alternatively, a radio frame may include multiple slots, and a slot may include at least one symbol. It should be noted that in this embodiment, an OFDM symbol may also be simply referred to as a symbol.

[0113] Depending on the subcarrier spacing, the length of each symbol can be different, and therefore the time slot length can also be different. In the embodiments of this application, the time domain unit can also be replaced by: time domain resource unit or OFDM symbol, etc.

[0114] In this embodiment, one time-domain unit is used as an OFDM symbol for illustration. In other embodiments, the OFDM symbol can be replaced with other possible examples of OFDM symbols.

[0115] 2.CP.

[0116] The operation of adding a CP specifically involves copying the number of samples equal to the length of the CP at the end of each OFDM symbol to the beginning of each OFDM symbol. The CP can mitigate inter-symbol interference caused by multipath delay and can also enable time boundary alignment of the next time slot after symbols are combined into a time slot.

[0117] 3. A possible form of signal transmitted in an IoT system.

[0118] The following is a schematic diagram of the structure of a signal transmitted in an IoT system, with reference to Figure 1.

[0119] A-IoT systems are asynchronous systems. Before an A-IoT device receives a data signal, it needs to obtain the start of the data signal and the length of the chip within it. Therefore, before sending the data signal, the network side needs to send a time acquisition to the A-IoT device. For reader-to-device (R2D) communication, a single R2D transmission includes time acquisition and a data signal. The time acquisition includes a start-indicator signal and a clock acquisition signal, while the data signal is transmitted via the data channel. Time acquisition can also be called a time acquisition signal (TAS) or a time acquisition part (TAP).

[0120] For R2D transmission, the data channel is called the physical reader-to-device channel (PRDCH). Optionally, PRDCH can also be replaced by the ambient physical downlink shared channel (APDSCH). For ease of description, PRDCH is used as an example below. In this embodiment, PRDCH can also be replaced by other examples of data channels, such as APDSCH.

[0121] In this context, "start indicator signal" can be replaced with "start indicator part" (SIP), and "clock acquisition signal" can be replaced with "clock acquisition part" (CAP). For ease of description, SIP and CAP will be used as examples below. However, in this embodiment, SIP can also be replaced with other examples of the start indicator part, and CAP can also be replaced with other examples of the clock acquisition part.

[0122] For example, referring to Figure 1, the SIP precedes the CAP. There is no time interval between the SIP and CAP; that is, the end of the SIP marks the beginning of the CAP. Furthermore, the CAP precedes the data signal, and there is no time interval between them; that is, the end of the CAP marks the beginning of the data signal. It can be understood that in R2D transmission, the data signal is transmitted in the PRDCH, and the transmission of the data signal can also be described as PRDCH transmission, or data channel transmission, etc. Correspondingly, the beginning of the data signal can be described as the beginning of the data channel or the beginning of data transmission.

[0123] SIP can be used to determine or indicate the start of data transmission. Since the end of SIP marks the start of CAP, and the end of CAP marks the start of data signals, SIP can be used to determine the start of data transmission. It can also be described as: start indication information can be used to determine the start of CAP, or SIP can be used to determine the start of PRDCH.

[0124] CAP can be used to determine the chip length of a data signal and the start of a PRDCH. In the description of embodiments in this application, chip length can also be described as: chip duration, chip time length, or the OFDM symbol of the chip, etc. For example, the chip length of a PRDCH can also be described as the chip duration of the PRDCH, or the transmitted OFDM symbol of the PRDCH, etc. CAP can be used to determine the chip length in data transmission / data signal / data channel. Alternatively, the clock-acquisition part provides at least the chip synchronization of the subsequent physical channel transmission. The process by which an A-IoT device detects SIP and CAP and performs corresponding operations based on SIP and CAP. When the subcarrier spacing is fixed, the duration of a symbol is fixed. An OFDM symbol includes multiple chips, and the lengths of these multiple chips may be different.

[0125] Figure 2 illustrates an exemplary architecture diagram of a communication system 1000 applicable to an embodiment of this application. As shown in Figure 2, the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include an Internet 300. The wireless access network 100 may include at least one wireless access network device (110a and 110b in Figure 2) and at least one terminal device (120a-120j in Figure 2). The terminal device is wirelessly connected to the wireless access network device, and the wireless access network device is wirelessly or wiredly connected to the core network. The core network device and the wireless access network device may be independent physical devices, or the functions of the core network device and the logical functions of the wireless access network device may be integrated on the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the wireless access network device. Terminal devices and wireless access network devices may be interconnected via wired or wireless means. Figure 2 is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 2.

[0126] The network devices involved in the embodiments of this application include, for example, radio access network (RAN) devices. RAN devices can be base stations, evolved NodeBs (eNodeBs or eNBs), transmission reception points (TRPs), transmission points (TPs), base stations in 5G mobile communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems; they can also be modules or units that perform some of the functions of a base station, for example, they can be central units (CUs), distributed units (DUs), or radio units (RUs). The CU (Radio Control Unit) performs the functions of the radio resource control protocol and packet data convergence protocol (PDCP) of the base station, and can also perform the functions of the service data adaptation protocol (SDAP). The DU (Radio Link Control Unit) performs the functions of the radio link control layer and medium access control (MAC) layer of the base station, and can also perform some or all of the physical layer functions. For specific descriptions of the above-mentioned protocol layers, please refer to the relevant technical specifications of the 3rd Generation Partnership Project (3GPP). The CU and DU can be set up separately, or they can be included in the same network element, such as in the baseband unit (BBU). The MAC layer can also be the media access control layer. The RU (Radio Unit) can be included in radio frequency equipment or radio frequency units, such as in the remote radio unit (RRU), active antenna unit (AAU), or remote radio head (RRH). In different systems, CU, DU, or RU may also have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (ORAN) system, a CU can also be called an open CU (open-CU, O-CU), a DU can also be called an open DU (open-DU, O-DU), and a RU can also be called an open RU (open-RU, O-RU).In this application, any of the following units—CU (or CU control plane (CU-CP), CU user plane (CU-UP), DU, and RU)—can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU-CP can also be called open-CU-CP (O-CU-CP), and CU-UP can also be called open-CU-UP (O-CU-UP).

[0127] Wireless access network equipment can be a macro base station (as shown in Figure 2, 110a), a micro base station or an indoor station (as shown in Figure 2, 110b), or a relay device, relay node, or donor node, etc. The embodiments of this application do not limit the specific technology or equipment form used in the wireless access network equipment. For ease of description, the following description uses a base station as an example of wireless access network equipment.

[0128] Terminal devices can also be referred to as user equipment (UE), mobile stations, mobile terminal devices, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, airships, ships, robots, robotic arms, smart home devices, sensors, in-vehicle equipment, on-board units (OBU), roadside units (RSU), relay nodes with mobility capabilities, etc. The embodiments of this application do not limit the specific technologies or device forms used in the terminal devices.

[0129] The aforementioned terminal devices can establish connections with the operator's network through interfaces provided by the operator's network (such as N1), and use data and / or voice services provided by the operator's network. The terminal devices can also access the Domain Name System (DNS) through the operator's network, and use operator services deployed on the DNS, and / or services provided by third parties. These third parties can be service providers outside of the operator's network and the terminal devices, and can provide other data and / or voice services to the terminal devices. The specific form of these third parties can be determined according to the actual application scenario and is not limited here.

[0130] Base stations and terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminal equipment.

[0131] The roles of base stations and terminal devices can be relative. For example, the helicopter or drone 120i in Figure 2 can be configured as a mobile base station. For terminal devices 120j that access the wireless access network 100 through 120i, terminal device 120i is a base station; however, for base station 110a, 120i is a terminal device, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminal devices can be collectively referred to as communication devices. 110a and 110b in Figure 2 can be called communication devices with base station functions, and 120a-120j in Figure 2 can be called communication devices with terminal device functions.

[0132] Communication between base stations and terminal devices, between base stations, and between terminal devices can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0133] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal device can be executed by modules (such as chips or modems) within the terminal device, or by a device that includes terminal device functions.

[0134] In this application, the base station sends downlink signals or downlink information to the terminal device, with the downlink information carried on the downlink channel; the terminal device sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. In order to communicate with the base station, the terminal device needs to establish a radio connection with a cell controlled by the base station. The cell with which the terminal device has established a radio connection is called the serving cell of the terminal device. When the terminal device communicates with this serving cell, it is also subject to interference from signals from neighboring cells.

[0135] The technical solutions provided in the embodiments of this application can be applied to various communication systems, such as cellular systems related to the 3rd Generation Partnership Project (3GPP), such as Long Term Evolution (LTE) communication systems, 5th Generation (5G) mobile communication systems / New Radio (NR) communication systems, or future-oriented evolution systems, or other similar communication systems. Other similar communication systems include Wireless Fidelity (WiFi), Vehicle-to-Everything (V2X), Spark Link systems, Bluetooth systems, Near Field Communication (NFC) systems, and Internet of Things (IoT) systems, such as Ambient IoT (A-IoT / A-IoT), Narrow Band Internet of Things (NB-IoT), etc. Alternatively, the solutions provided in the embodiments of this application can also be applied to communication systems that integrate two or more of the above systems. It should be understood that IoT technology is widely used in various industries; for example, IoT technology can be applied to scenarios such as logistics, warehousing, industrial manufacturing, identity recognition, or environmental monitoring. IoT is implemented based on RFID technology. RFID technology is a contactless communication technology that uses radio frequency communication. Its principle is that the reader and the tag do not need to make contact and communicate data through radio waves.

[0136] In one possible implementation, the technical solution provided in this application is applicable to backscattering systems. A backscattering system generally consists of an exciter, a receiver, and a transmitter. Its communication link includes a downlink from the exciter to the reflector and an uplink from the reflector to the receiver. Figure 3 illustrates a backscattering system using a tag and a reader. The reader can send a carrier signal to the tag, which receives the carrier signal through an antenna. The solid line in Figure 3 represents the carrier signal sent by the reader, and the dashed line represents the reflected signal transmitted by the tag based on the carrier signal reflection. The tag can adjust the information to be transmitted in the reflected signal. Through this method, the tag uses a low-precision, low-power mid-to-low frequency ring oscillator or a completely oscillator-free method to receive downlink signals, further reducing the power consumption of the tag's downlink reception. Optionally, the carrier can also be understood as an excitation signal, which can be sent by other devices besides the reader or devices integrated into the reader (e.g., external nodes).

[0137] For example, please refer to Figure 4A, which illustrates a communication system to which this application embodiment applies. As shown in Figure 4A, the communication system includes a network device and an A-IoT device. The A-IoT device can be a standalone device, or it can be integrated with a terminal device, i.e., the A-IoT device is part of the terminal device. In this communication system, the network device can communicate with the A-IoT device. It should be noted that Figure 3 uses the example of a network device communicating with the A-IoT device. In possible scenarios, the device communicating with the A-IoT device can be other than the network device, such as a terminal device. For example, the A-IoT device can be a device with a peak power consumption of ~1 microwatt (μW), also referred to as device 1. Or the A-IoT device can be a device with a peak power consumption of ≤ several hundred μW. A device with a peak power consumption of ≤ several hundred μW that uses an externally provided carrier for backscattering is called device 2a, or a device that uses an internally generated carrier for transmission is called device 2b.

[0138] For example, please refer to Figure 4B, which illustrates another communication system applicable to embodiments of this application. As shown in Figure 4B, this communication system includes a network device, an intermediate node, and an A-IoT device, wherein the intermediate node can forward information between the network device and the A-IoT device. The relay node can be, for example, a terminal device, that is, the terminal device acts as an intermediate node between the network device and the A-IoT device. In this example, the A-IoT device transmits information to the terminal device, and the terminal device forwards the information to the network device through the Uu interface; or, the network device transmits information to the terminal device, and the terminal device then forwards the information to the A-IoT device; or, based on resources pre-authorized or pre-configured by the network device, the terminal device conducts bidirectional communication with the A-IoT device through the A-IoT air interface.

[0139] Intermediate nodes can also be devices other than terminal devices, such as network devices. This network device can be located outdoors, while the terminal device and the A-IoT device can be located indoors. Essentially, the outdoor network device communicates with the indoor A-IoT device through an indoor intermediate node. Optionally, the intermediate node can be called an intermediate UE (User Equipment). For another example, an intermediate node can be an integrated access and backhaul (IAB) node. An IAB node can act as an intermediary between the network device and the A-IoT device. The A-IoT device transmits information to the IAB node, and the IAB node forwards this information to the network device via the Uu interface; alternatively, the network device transmits information to the IAB node, and the IAB node then forwards the information to the A-IoT device. Based on pre-authorized or pre-configured resources of the network device, the IAB node can also communicate bidirectionally with the A-IoT device via the A-IoT air interface. For yet another example, an intermediate node can be a relay node. Relay nodes can act as intermediary nodes between network devices and A-IoT devices. A-IoT devices transmit information to the relay node, and the relay node forwards this information to the network device via the Uu interface; alternatively, network devices transmit information to the relay node, and the relay node then forwards the information to the A-IoT device. Based on pre-authorized or pre-configured resources of the network device, relay nodes can also conduct bidirectional communication with A-IoT devices via the A-IoT air interface.

[0140] Optionally, the energy required for the A-IoT device to transmit information is provided by an excitation signal, which can come from an exciter. This exciter can be a network device, a terminal device, or a device other than a network device or a terminal device. In possible scenarios, the functions of the device communicating with the A-IoT device (e.g., a reader / writer) can be further separated. Functionally, the reader / writer can be divided into a receiver and an exciter, which can be deployed on different network devices. For example, the receiver is deployed on a first network device, and the exciter on a second network device. The first network device performs the reader / writer's receiving function. The second network device performs the reader / writer's transmitting function. The receiver is also called a receiving end or receiving unit, and the exciter is also called an excitation end or excitation unit.

[0141] IoT systems can include a variety of devices, such as smart water meters, shared bicycles, and devices for sensing and data collection in smart cities, environmental monitoring, smart homes, and forest fire prevention. To increase the number of devices that can be accommodated in IoT scenarios, reducing the size of IoT devices is generally a trend. However, due to various factors, the size of IoT devices cannot be reduced to a minimum; for example, IoT devices require high-capacity batteries. Therefore, for IoT devices with limited size, it is not feasible to incorporate high-capacity batteries, and the goal is to reduce the power consumption of IoT devices to extend their battery life.

[0142] Compared to NR terminal devices (e.g., NR terminal devices of release (R) 15, R16, R17), A-IoT devices have at least one of the following characteristics:

[0143] 1) Maximum Bandwidth: The maximum bandwidth of an A-IoT device can be less than the maximum bandwidth of R15 and R16 terminal devices (e.g., 100MHz). The maximum bandwidth of an A-IoT device can also be less than the maximum bandwidth of the reduced capability (RedCap) in R17 terminal devices (e.g., 20MHz). For example, the maximum bandwidth of an A-IoT device is 1 resource block (RB), 1.44MHz, 1.5MHz, 2.88MHz, 3MHz, etc.

[0144] 2) Number of antennas supported: A-IoT devices support one transmit antenna and one receive antenna, or A-IoT devices support one transmit antenna and two receive antennas.

[0145] 3) The transmission channels of A-IoT devices and readers are not aligned with the start and / or boundaries of NR time slots, frames, symbols, etc.

[0146] 4) The transmission between A-IoT devices and readers uses a single-carrier waveform.

[0147] 5) The transmission channel from the reader to the A-IoT device is not aligned with the start and / or end boundaries of the NR's time slots, frames, etc.; the transmission channel from the reader to the A-IoT device is aligned with the start and / or end boundaries of the NR's OFDM symbols.

[0148] 6) The transmission from the reader to the A-IoT device uses OFDM waveform.

[0149] 7) A-IoT devices support at least one of the following modulation methods: binary on-off keying (OOK), frequency-shift keying (FSK), binary phase shift keying (BPSK), and minimum shift keying (MSK). FSK can also be called binary frequency shift keying (BFSK), 2FSK, or OOK-FSK.

[0150] IoT devices include those requiring batteries (also known as IoT devices with energy storage or active IoT devices), those without batteries (also known as IoT devices without energy storage or passive IoT devices), and those with limited energy storage (also known as semi-passive IoT devices). IoT devices with limited energy storage do not require manual battery replacement or charging. Active IoT devices can independently generate signals and have active radio frequency components for transmission. Passive IoT devices have no energy storage, cannot independently generate signals, and transmit based on backscatter communications. Semi-passive IoT devices have energy storage but cannot independently generate signals and transmit based on backscatter communications. Passive or semi-passive IoT devices can also be called A-IoT devices; A-IoT devices can provide services and communicate by harvesting energy from the environment.

[0151] A typical IoT device is a tag. Tags can also be called RFID tags, electronic tags, or IoT tags. In this embodiment, the tag can function as a terminal device to communicate with network devices. The term "tag" is merely an optional designation and may change; for example, "A-IoT tag" may be replaced with other names. This embodiment does not limit the name used. For ease of description, the term "tag" will continue to be used as an example below.

[0152] The tag uses a low-precision, low-power mid-to-low frequency ring oscillator or a completely oscillator-less receiver to receive downlink signals. When the tag is operating, the energy and / or carrier for communication is supplied by the reader, and communication is based on a reflected carrier.

[0153] A tag is a miniature wireless transceiver device, mainly consisting of a built-in antenna, coupling element, and chip. The tag's chip contains storage space that enables a reader to read or write tag data. After receiving radio frequency (RF) signals from the reader via its antenna, the tag can couple these signals through the coupling element. This coupling channel allows power to be supplied to the tag's chip, and the data stored in the chip can be fed back to the reader via the antenna. A communication network based on cellular network infrastructure, including readers and tags, can be called A-IoT.

[0154] There are various types of A-IoT devices, and this application does not limit the methods for classifying A-IoT device types. Several methods for classifying A-IoT device types are illustrated below.

[0155] In classification method 1, A-IoT devices can be divided into three categories: Type 1 (also known as device1), Type 2 (also known as device2a), and Type 3 (also known as device2b). Type 1 A-IoT devices do not support uplink or downlink amplification, and their uplink transmission relies on an externally provided carrier wave using backscatter, rather than generating its own signal. Type 2 A-IoT devices support either uplink or downlink amplification, and their uplink transmission relies on an externally provided carrier wave using backscatter, also without generating its own signal. Type 3 A-IoT devices support either uplink or downlink amplification, and their uplink transmission relies on an internally generated carrier wave.

[0156] Optionally, Type 1 A-IoT devices have an output power consumption of approximately 1 μW and some energy storage capacity. Type 2 A-IoT devices have a peak power of no more than several hundred μW. Type 3 A-IoT devices have a peak power of no more than several hundred μW.

[0157] Optionally, the initial sampling frequency offset (SFO) of Type 1 A-IoT devices is at most 10. X ppm, X can be 5, 4, 3, or 2. The maximum initial sampling clock skew for Type 2 A-IoT devices is 10. X2 ppm, X2 can be 5, 4, 3, or 2. The maximum initial sampling clock skew for Type 3 A-IoT devices is 10. X3 ppm, X3 can be 5, 4, 3 or 2.

[0158] As shown in Figure 5A, Type 1 A-IoT devices include:

[0159] 1. Antenna: The receiver / transmitter can share or be separated for receiving radio frequency (RF) energy.

[0160] 2. Matching network: Matches the impedance between the antenna and other components (including modules related to the RF energy harvester and receiver).

[0161] 3. RF energy harvester: including rectifiers used to convert radio frequency signals (AC) into DC.

[0162] 4. Energy storage device (e.g., capacitor): Stores the collected energy from the RF energy receiver.

[0163] 5. Power Management Unit (PMU): Manages the energy stored in the energy harvester and provides energy to active modules that require energy supply.

[0164] 6. Digital baseband logic: This includes functional modules such as encoders, decoders, and controllers.

[0165] 7. Memory: Includes two types of memory: 1) Non-volatile memory, such as electrically erasable programmable read-only memory (EEPROM, EEPROM); 2) Registers that temporarily store information, which can only store information when there is sufficient energy in the energy storage.

[0166] 8. Clock generator: Provides clock signals.

[0167] 9. Receive related modules, such as:

[0168] 1) RF bandpass filter (BPF): Improves frequency selectivity.

[0169] 2) RF envelope detector: Converts RF signals to baseband.

[0170] 3. Baseband low-pass filter (LPF): Filters out harmonics and high-frequency components, improving the signal quality input to the comparator.

[0171] 4) Comparator: determines the high / low (level) of the input signal.

[0172] 10. Transmit-related modules, such as: backscatter modulator: switch impedance to modulate the backscatter signal with the transmit signal from the baseband logic.

[0173] 11. Clock generator: Provides clock signals.

[0174] As shown in Figure 5B, Type 2 A-IoT devices include:

[0175] 1. Antenna: RF energy reception and receiver / transmitter can be shared or separated.

[0176] 2. Matching network: Matches the impedance between the antenna and other components (including modules related to the RF energy harvester and receiver).

[0177] 3. RF energy harvester: includes a rectifier that converts radio frequency signals (AC) into DC.

[0178] 4. Energy Management Unit (PMU): Manages the energy stored from the energy harvester and provides energy to the active modules that need energy supply.

[0179] 5. Digital baseband logic: This includes functional modules such as encoders, decoders, and controllers.

[0180] 6. Memory: Includes two types of memory: 1) Non-volatile memory, such as EEPROM. 2) Registers that temporarily store information, which can only store information when there is sufficient energy in the energy storage.

[0181] 7. Clock generator: Provides clock signals.

[0182] 8. Local oscillator (LO): Generates the carrier frequency for the transmitter or the carrier frequency offset for the intermediate frequency (IF) receiver.

[0183] 9. Receiving relevant modules, such as:

[0184] 1) RF BPF: Improves frequency selectivity.

[0185] 2) Mixer: Converts RF signals to intermediate frequency signals.

[0186] 3) Intermediate frequency (IF) amplifier (amf): amplifies intermediate frequency signals.

[0187] 4) Intermediate Frequency (IF) Filter: The intermediate frequency filter removes unwanted RF and LO signals.

[0188] 5) Intermediate frequency (IF) envelope demodulation (ED): Detecting the envelope from the intermediate frequency signal.

[0189] 6) Baseband circuit test board (bread board, BB) amplifier (amf): depending on the implementation, may or may not be present.

[0190] 7) Baseband BB LPF: Filters out harmonics and high-frequency components, improving the signal quality input to the comparator / analog-to-digital converter (ADC).

[0191] 8) Comparator / N-bit ADC.

[0192] 10. Launch-related modules, such as:

[0193] 1) Transmit modulation: Modulate baseband bits according to the modulation method. This part can be part of the baseband logic module.

[0194] 2) Digital-to-analog converter (DAC): Converts digital signals into analog signals.

[0195] 3) LPF: Filter out unwanted signals.

[0196] 4) Mixer: Upconverts baseband signals to the RF frequency range.

[0197] 5) Power amplifier (PA): If present, amplifies the transmitted signal.

[0198] 11. Energy storage device (e.g., capacitor): Stores the collected energy from the RF energy receiver.

[0199] In addition, the chip shown in Figure 5B also includes a low noise amplifier (LNA) and an energy harvester (other than RF).

[0200] In classification method 2, A-IoT devices can be divided into three categories: passive A-IoT devices, semi-passive A-IoT devices, and active A-IoT devices. Among them, passive A-IoT devices and semi-passive A-IoT devices can use reflection-based communication methods, while active A-IoT devices use actively generated carrier communication methods.

[0201] In classification method 3, A-IoT devices can also be divided into three categories: device A, device B, and device C. Device A has no energy storage and cannot generate signals independently; it uses backscattering to transmit signals. Device B has energy storage but cannot generate signals independently; it also uses backscattering to transmit signals, and the energy stored in device B can amplify the reflected signal. Device C has energy storage, can generate signals independently, and has active radio frequency components for transmission.

[0202] The A-IoT devices in this application embodiment can be classified according to classification method 1, classification method 2, or classification method 3, and this application embodiment is applicable to any category of A-IoT devices under classification method 1, classification method 2, or classification method 3. Alternatively, the A-IoT tags in this application embodiment may also have other classification methods or may not be classified at all; there are no restrictions on this.

[0203] In the embodiments of this application, "transmission" includes "sending" and / or "receiving." "Sending" and "receiving" indicate the direction of signal transmission. For example, "sending information to XX" can be understood as the destination of the information being XX, which can include direct transmission via the air interface or indirect transmission by other units or modules via the air interface. "Receiving information from YY" can be understood as the source of the information being YY, which can include direct reception from YY via the air interface or indirect reception from YY by other units or modules via the air interface. "Sending" can also be understood as the "output" of a chip interface, and "receiving" can also be understood as the "input" of a chip interface. In other words, sending and receiving can occur between devices, such as between access network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via a bus, wiring, or interface.

[0204] To improve communication performance, a CP (Clipping Path) is introduced into the signals transmitted between devices. However, the introduction of CP can cause sudden rising or falling edges in the signal. These sudden rising or falling edges can lead to false detections during device detection, and combined with the line code used, can cause false bit detections, thus degrading communication performance. This will be explained below with reference to Figure 6.

[0205] Please refer to Figure 6. Figure 6(a) exemplifies a possible structural form of an OOK signal, as shown in the figure. This signal includes OFDM symbol #1 and OFDM symbol #2. Figure 6(b) shows a schematic diagram of the signal structure obtained by the network device after adding CP to Figure 6(a). As shown in Figure 6(b), the operation of adding CP specifically includes copying the sample number of the CP length at the end of each OFDM symbol to the beginning of each OFDM symbol. Figure 6 uses Manchester encoding in R2D as an example. As can be seen from Figure 6(b), the level of the last chip in OFDM symbol #1 is OFF, and the level of the first chip in OFDM symbol #2 is OFF. The CP of OFDM symbol #2 is copied from the end of OFDM symbol #2. The level of the end of OFDM symbol #2 (i.e., the last chip) is ON. Therefore, the introduction of CP will cause a burst edge, i.e., a rising edge and a falling edge, between the last chip of OFDM symbol #1 and the first chip of OFDM symbol #2.

[0206] In a Manchester coding detection method, the terminal device uses the preceding edge of the last chip of an OFDM symbol as the tracking clock information, serving as a reference time. For example, the terminal device performs detection at (reference time + T) and (reference time + 2T), where T is the length of a chip. If the terminal device detects an edge at both (reference time + T) and (reference time + 2T), the current information bit is the same as the previous information bit. If the terminal device does not detect an edge at (reference time + T) but only at (reference time + 2T), the current information bit is inverted compared to the previous information bit. Referring to Figure 6(a), the terminal device uses the last falling edge of the OFDM symbol as the reference time. Without the introduction of CP, the terminal device does not detect an edge at (reference time + T) but detects an edge at (reference time + 2T), so the first information bit of OFDM symbol #2 is inverted compared to the previous information bit, for example, detected as bit "1". However, due to the introduction of CP, as shown in Figure 6(b), a false edge that should not exist appears (in this embodiment, a false edge means an edge generated due to the introduction of CP), causing the terminal device to detect the edge at time (reference time + T). In accordance with the aforementioned detection method, the terminal device will consider the first information bit of OFDM symbol #2 to be the same as the previous information bit, for example, it will be mistakenly detected as bit "0", thus causing errors in data transmission.

[0207] The above analysis shows that the introduction of CP will cause sudden rising or falling edges in the signal. This is because the clock sampling offset (SFO) of A-IoT devices is relatively large (e.g., SFO is 10).5 In the case of parts per million (PPM) (where PPM is an error measurement, 10% deviation), the demodulation device needs to perform clock tracking based on the rising or falling edges that occur according to the rules brought about by the line code, and detect information bits by the state of the edge (rising or falling edge) or the time length between edges. At this point, sudden rising or falling edges introduced by the CP can cause errors in the detection of the edge state or the time length between edges. Combined with the line code used, this can lead to false bit detections, resulting in a degraded communication performance.

[0208] In view of this, embodiments of this application provide several possible implementation schemes to reduce the interference of CP introduced on decoding, thereby reducing the false detection rate and improving communication performance. Embodiments of this application can also flexibly select implementation schemes based on the value of M, thus comprehensively considering the advantages and disadvantages of various implementation schemes and selecting a more reasonable implementation scheme under different circumstances, thereby improving communication performance. The following description is in conjunction with the accompanying drawings.

[0209] Based on the embodiments shown in at least one of Figures 2, 3, 4A, 4B, 5A, or 5B, and the other aforementioned content, embodiments of this application provide a possible communication method. For ease of understanding, this communication method is described from the perspective of the interaction between the transmitting end device and the receiving end device.

[0210] The transmitting device can be the transmitting device itself, or a component within the transmitting device (e.g., a module, communication module, circuitry or chip responsible for communication functions, such as a modem chip, also known as a baseband chip, or a system-on-a-chip (SoC) chip or system-in-package containing a modem core). The transmitting device can be a network device, which can be a network device or a component of that network device (e.g., a module, communication module, circuit or chip responsible for communication functions, such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core). It can also be a logical node, logical module, or software that implements the device's functions. For example, the network device includes a CU, DU, or RU. For ease of description, the following example uses a network device as the transmitting device. Optionally, the network device can be a card reader or a reader / writer, or the network device can have the functions of a card reader or a reader / writer.

[0211] The receiving device can be a receiving device or a component within that receiving device (e.g., a module, communication module, circuitry or chip responsible for communication functions such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core; it can also be a logic node, logic module, or software that implements the device's functions). For example, if the receiving device is a terminal device, it can be a terminal device or a component within that terminal device (e.g., a module, communication module, circuitry or chip responsible for communication functions such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core; it can also be a logic node, logic module, or software that implements the device's functions). The device's functional logic nodes, logic modules, or software. For ease of description, the following example uses the method applied to a terminal device. For example, the terminal device is an A-IoT device. Another example is a tag. There are no restrictions on the type of A-IoT device. For example, the A-IoT device in this embodiment can be a type 1 A-IoT device or a type 2 A-IoT device; there are no restrictions. For the type of A-IoT device, please refer to the preceding description. The network device can be the network device in Figure 4A or Figure 4B, or it can be a chip (system) in the network device in Figure 4A or Figure 4B. The network device has some or all of the functions of a reader / writer. When the solution of this embodiment is applied to the network architecture shown in Figure 4B, the network device can be a base station or an intermediate node.

[0212] In one possible implementation, both the A-IoT device and the reader / writer can be implemented based on cellular network infrastructure, or both can be devices within the cellular network. For example, the reader / writer's functionality can be implemented by a network device or a terminal device, and the A-IoT device can be implemented by a terminal device within the cellular network. For instance, the A-IoT device can be an extremely low-power, extremely low-complexity IoT terminal. When a terminal device has the functionality of an A-IoT device, then the terminal device can perform contactless data communication with a network device or another terminal device.

[0213] Please refer to Figure 7, which is a flowchart illustrating the communication method provided in an embodiment of this application. Figure 7 describes the method from the perspective of interaction between the terminal device and the network device. It should be understood that the communication method can also be implemented by other devices, such as a chip or communication device with communication capabilities. Furthermore, the processing performed by a single execution entity can be divided into multiple execution entities, which can be logically and / or physically separated. For example, the processing performed by the network device can be performed by at least one of multiple entities into which the network device is divided. As shown in Figure 7, the flow of this communication method includes the following step 701.

[0214] Step 701: The network device sends a first signal.

[0215] Correspondingly, the terminal device receives the first signal.

[0216] For example, before step 701, the network device may first determine (or generate, or obtain) the first signal, and then send the first signal. As another example, if the first signal includes data, the network device may process the data to obtain (or generate, or determine) the first signal. As yet another example, the terminal device receives the first signal and then detects it. As yet another example, if the first signal includes data, the terminal device receives the first signal and obtains the data from the first signal.

[0217] For example, the first signal includes a clock capture section and a PRDCH. Or the first signal includes a PRDCH. Or the first signal includes a start indication section, a clock capture section, and a PRDCH. A description of the clock capture section and the PRDCH can be found above and will not be repeated here.

[0218] The first signal includes K OFDM symbols, where K is a positive integer. Each of the K OFDM symbols includes M chips, where M is a positive integer. Each of the K OFDM symbols may include multiple chips. The level corresponding to each chip can be high or low, or the bits corresponding to each chip can be {1} or {0}, where {1} equals high level and {0} equals low level. Alternatively, the state corresponding to each chip can be ON or OFF, where ON equals high level and OFF equals low level. Alternatively, the level can be replaced with "OOK symbol", with ON replaced by OOK symbol 1 and OFF replaced by OOK symbol 0. In this embodiment, ON can also be written as "on" and OFF can also be written as "off". The length of an OFDM symbol is fixed and equal to the reciprocal of the subcarrier spacing. Here, the length of an OFDM symbol does not include the length of the cyclic prefix (CP). In this embodiment, the length of a symbol can be replaced by the duration of the symbol or by the time length. In an OFDM symbol comprising M chips, the length of each of the M chips is 1 / M of the length of the OFDM symbol. Alternatively, the length of the OFDM symbol is the length of the M chips, or the length of the OFDM symbol is M times the length of a single chip. The length of an OFDM symbol can be replaced with the length of a single OFDM symbol, and the length of a single chip can be replaced with the length of a single chip. Each OFDM symbol comprising M chips can also be interpreted as the value of M remaining unchanged within the OFDM symbol; this can be written as: "while M value is kept unchanged during the remaining OFDM symbols." Any two chips in each OFDM symbol across K OFDM symbols may have the same or different lengths, or each OFDM symbol may have multiple chip lengths.

[0219] In one possible implementation, the clock capture portion can be used to determine the chip length of the data signal. For example, the clock capture portion can carry information indicating the value of M. The first signal may or may not include a clock capture portion. For example, if the first signal includes a clock capture portion, the terminal device can obtain the value of M from the first signal. Alternatively, if the first signal does not include a clock capture portion, such as if the first signal includes a PRDCH, the terminal device can receive the clock capture portion before receiving the first signal and obtain the value of M from that clock capture portion. When the first signal includes a PRDCH, the terminal device can detect the PRDCH in the first signal based on the value of M. Or, if the first signal includes data, the terminal device can detect the first signal based on the value of M and obtain the data in the first signal.

[0220] In one possible implementation, the first signal includes a CP (Carrier Component). For example, the network device adds a CP to each of the K OFDM symbols. Thus, each OFDM symbol in the first signal has a corresponding CP added. This implementation can guarantee the subcarrier orthogonality of the first signal and other signals in the NR system, avoiding interference problems between the first signal and other signals in the NR system under in-band deployment. For example, the network device can generate each OFDM symbol according to Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) and add a CP to each OFDM symbol.

[0221] To reduce the interference of CP on decoding performance, this application provides two possible implementation methods through the following embodiments A1 and A2. For example, in embodiment A1, the K OFDM symbols include a first OFDM symbol, which may include padding chips. In embodiment A2, the K OFDM symbols include a second OFDM symbol, where M chips are used to carry the clock capture portion and / or PRDCH. For example, in embodiment A2, the second OFDM symbol in the first signal does not include padding chips.

[0222] In implementation A1, the K OFDM symbols include a first OFDM symbol, which may include padding chips.

[0223] For example, the last X chips of the first OFDM symbol are padding chips. X is a positive integer. In one possible implementation, the last X chips of the first OFDM symbol being padding chips can include / become / be understood as: the last X chips of the first OFDM symbol are padding chips, and the padding chips are not used to carry the clock acquisition part (CAP) and / or the physical reader device channel (PRDCH), or the padding chips are not used to carry the bits of CAP and / or PRDCH, or the padding chips are not used in carrying the data of CAP and / or PRDCH. In the embodiments of this application, padding chips can be abbreviated as "padding".

[0224] In one possible implementation, one or more padding chips may be added to the starting position of the first OFDM symbol. The implementation scheme A1 can also be described as / including / replaced by: inserting padding chips at the beginning and end positions of the OOK chip or inserting padding chips at the end of the OOK chip. This can be described in English as: "inset padding chips at both start and end OOK chips or only at end OOK chips".

[0225] In the solutions provided in this application, the network device can flexibly choose the implementation method that can be used according to the actual situation. For example, the network device uses the solution of implementation method A1 when the first condition is met, and uses the solution of implementation method A2 when the second condition is met.

[0226] The first and second conditions can be set based on the value of M or the type of signal. For example, the first condition may include M being greater than or equal to a first threshold, and the second condition may include M being less than the first threshold. Another example is that the first condition includes M being greater than the first threshold, and the second condition includes M being less than or equal to the first threshold. Yet another example is that the first condition may include the first signal being a first type of signal or a first-class signal, and the second condition may include the first signal being a second type of signal or a second-class signal. The second type of signal or second-class signal may be TAS or CAP. The first type of signal or first-class signal may be PRDCH. The following description uses the example of the first condition being M being greater than or equal to the first threshold and the second condition being M being less than the first threshold. In practical applications, "M being greater than or equal to the first threshold" in this embodiment can be replaced with other examples of the first condition, and "M being less than the first threshold" in this embodiment can be replaced with other examples of the second condition.

[0227] In one possible implementation, when the first signal includes a start indication portion, a clock capture portion, and a PRDCH, and the first OFDM symbol includes a chip for carrying the clock capture portion and a chip for carrying the PRDCH, the preceding OFDM symbol of the first OFDM symbol includes a chip for carrying the start indication portion. When the chip for carrying the start indication portion included in the preceding OFDM symbol of the first OFDM symbol ends at a level OFF, and the first chip of the first OFDM symbol is at a level ON, then the levels of the subsequent X filler chips of the first OFDM symbol are fixed at OFF. In this case, the end level OFF of the start indication portion includes the CP of the first OFDM symbol. Conversely, when the chip for carrying the start indication portion included in the preceding OFDM symbol of the first OFDM symbol ends at a level ON, and the first chip of the first OFDM symbol is at a level OFF, then the levels of the subsequent X filler chips of the first OFDM symbol are fixed at ON. In this case, the end level ON of the start indication portion includes the CP of the first OFDM symbol.

[0228] In this embodiment of the application, an OFDM symbol may include a chip for clock capture, a chip for carrying the clock capture portion, or a clock capture portion; any two of these three descriptions can be interchanged. The chip for carrying the clock capture portion and the chip for the clock capture portion can be interchanged. Similarly, an OFDM symbol may include a chip for PRDCH, a chip for carrying the PRDCH, or a PRDCH; any two of these three descriptions can be interchanged. The chip for carrying the PRDCH and the chip for the PRDCH can be interchanged. Likewise, an OFDM symbol may include a chip for start indication, a chip for carrying the start indication portion, or a start indication portion; any two of these three descriptions can be interchanged. The chip for carrying the start indication portion and the chip for the start indication portion can be interchanged.

[0229] K may be greater than 1 or equal to 1, and these two cases can correspond to different implementation methods, at least one of which can be satisfied. For example, in one possible implementation method, when M is greater than or equal to the first threshold, and K > 1, the first OFDM symbol satisfies at least one of the following implementation methods A1.1, A1.2, or A1.3. Alternatively, in one possible implementation method, when M is greater than or equal to the first threshold, and K = 1, the first OFDM symbol satisfies at least one of the following implementation methods A1.1 or A1.3.

[0230] In this embodiment, when M equals the first threshold, the OFDM symbol in the first signal can be implemented using either Implementation A1 or Implementation A2. Here, we will use Implementation A1 as an example. In this embodiment, ">" and "greater than", "<" and "less than", "=" and "equal to", "≥" and "greater than or equal to", and "≤" and "less than or equal to" can be interchanged. Related content in other locations can be found here and will not be repeated.

[0231] In implementation method A1.1, the voltage levels of the last X chips of the first OFDM symbol are the same as the voltage level of the first chip in the first OFDM symbol.

[0232] Figure 8 exemplifies one possible example of the first signal. Referring to Figure 8, which uses M=24, X=2, and OFDM#4 as the first OFDM symbol for illustration. Figure 8(a) exemplifies that the symbols of the first signal include OFDM#3 and OFDM#4. OFDM#3 and OFDM#4 are two symbols that are adjacent in the time domain. Figure 8(a) shows a schematic diagram of the signal structure without the network device adding CP to the first signal. Figure 8(b) shows a schematic diagram of the structure after the network device adds CP to the first signal. As shown in Figure 8(b), since the level of the first chip of OFDM#4 (the first OFDM symbol) is OFF, the levels of the next X chips of OFDM#4 (the first OFDM symbol) are also OFF. Furthermore, since the network device copies the levels on X chips when performing the CP addition operation before OFDM#4 (the first OFDM symbol), the level of the CP added by the terminal device is OFF. That is, the network device copies the levels on X chips as CP. Since the voltage levels of the X chips are the same as those of the first chip in the first OFDM symbol, the added CP will not include edges (rising and falling edges). Subsequent terminal devices can then remove the CP from the received first signal without leaving any edges in the CP (since there were originally no edges in the CP). This reduces the interference of the CP on decoding performance (see Figure 6 above for a related explanation; the absence of leftover edges in the CP avoids decoding errors caused by edge detection), thereby reducing the false positive rate during receiver detection and improving communication performance.

[0233] In implementation method A1.2, the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the OFDM symbol preceding the first OFDM symbol.

[0234] In this embodiment, the K OFDM symbols have a timing relationship in the time domain, and these K OFDM symbols can be sequentially adjacent in the time domain. The OFDM symbol preceding the first OFDM symbol refers to the OFDM symbol preceding the first OFDM symbol in the time domain direction. Figure 9 exemplarily illustrates a possible example of the first signal. For example, if the first OFDM symbol in Figure 9 is OFDM#4, then the OFDM symbol preceding the first OFDM symbol is OFDM#3.

[0235] Please refer to Figure 9, which illustrates the example with M=24, X=2, and OFDM#4 as the first OFDM symbol. Figure 9(a) exemplifies that the symbols of the first signal include OFDM#3 and OFDM#4. OFDM#3 and OFDM#4 are two symbols that are adjacent in the time domain. Figure 9(a) shows the structure of the signal without the network device adding CP to the first signal. Figure 9(b) shows the structure of the network device after adding CP to the first signal. As shown in Figure 9(b), since the level of the last chip of OFDM#3 (the OFDM symbol preceding the first OFDM symbol) is ON, the level of the last X chips of OFDM#4 (the first OFDM symbol) is ON. Furthermore, since the network device copies the level of X chips when it performs the CP addition operation before OFDM#4 (the first OFDM symbol), the level of the CP added by the terminal device is ON. That is, the network device copies the level of X chips as CP. Since the voltage levels of the X chips are the same as the voltage level of the last chip of the OFDM symbol preceding the first OFDM symbol, the added CP will not include edges (rising and falling edges). Subsequent terminal devices can remove the CP from the received first signal without leaving any edges in the CP (since there were originally no edges in the CP). This reduces the interference of the CP on decoding performance (see the relevant explanation in Figure 6 above; that is, without any remaining edges in the CP, decoding errors caused by edge detection can be avoided), thereby reducing the false positive rate during receiver detection and improving communication performance.

[0236] In implementation method A1.3, the voltage level of each of the last X chips of the first OFDM symbol is either ON or OFF.

[0237] In implementation method A1.3, for example, the level of the last X chips of the first OFDM symbol may be the same as or different from the level of the first chip in the first OFDM symbol. As another example, the level of the last X chips of the first OFDM symbol may be the same as or different from the level of the last chip of the preceding OFDM symbol. The level of each of the last X chips of the first OFDM symbol can be set independently, without considering other factors, such as a predefined value.

[0238] Since the voltage level of each of the X chips is either ON or OFF, when the network device copies one or more chips from the later part of the first OFDM symbol to the beginning as a CP (Clipping Point), the copied chips will not have edges. Subsequent terminal devices can then remove the CP from the received first signal, thereby reducing the interference of the CP on decoding performance, lowering the false detection rate at the receiver, and ultimately improving communication performance.

[0239] In one possible implementation, the first OFDM symbol is any one of the K OFDM symbols. Thus, each of the K OFDM symbols can execute the aforementioned scheme for the first OFDM symbol, thereby reducing the interference of the CP added to each of the K OFDM symbols on decoding performance, thereby lowering the false detection rate and improving communication performance.

[0240] In another possible implementation, the first OFDM symbol is any one of the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion. Thus, each of the remaining OFDM symbols, except those carrying the start indication portion, can execute the aforementioned scheme for the first OFDM symbol. This reduces the interference of the CP added to each of the K OFDM symbols on decoding performance, thereby lowering the false detection rate and improving communication performance.

[0241] In another possible implementation, the first OFDM symbol is the first OFDM symbol among the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion. For example, the K OFDM symbols in the time domain sequentially include OFDM symbol #11, OFDM symbol #12, and OFDM symbol #13. If S is 1, then the S OFDM symbols are OFDM symbol #11, and the OFDM symbols excluding the first S OFDM symbols are OFDM symbol #12 and OFDM symbol #13. The first OFDM symbol among the OFDM symbols excluding the first S OFDM symbols is OFDM symbol #12. Furthermore, the implementation of the remaining OFDM symbols excluding the first S OFDM symbols and the first OFDM symbol is not restricted, thereby increasing the flexibility of the scheme.

[0242] In one possible implementation, the value of X can also be related to the value of M. For example, the time length occupied by the X chips is related to the time length occupied by the CP. This allows for setting reasonable values ​​for X, thereby further improving communication performance. For instance, the time length occupied by the X chips is greater than or equal to the time length occupied by the CP. Thus, when the network device performs the operation of adding a CP, it can copy all or part of the levels from the X chips to the beginning of the first OFDM symbol as the CP, thereby avoiding copying chips outside the X chips as the CP. This further avoids the generation of edges (rising and / or falling edges) in the CP, thereby further reducing the interference of the CP on decoding performance, reducing the false positive rate during receiver detection, and thus improving communication performance. For another example, the X chips can be set according to a dedicated chip length, thereby minimizing the time-domain resources occupied by the X chips, reducing the overhead of the X chips, and thus improving transmission efficiency.

[0243] For example, when M is greater than 12, the value of X is 2 or 3. For example, when M is 32, the value of X is 3. Another example is when M is 16 or 24, the value of X is 2. Yet another example is when M is less than 12, the value of X is 1. For example, when M is 6 or 8, the value of X is 1. When M is 12, the value of X can be either 1 or 2. These examples allow the time length occupied by the X chips to be greater than or equal to the time length occupied by the CP. Therefore, when the network device performs the CP addition operation, it can copy all or part of the levels from the X chips to the beginning of the first OFDM symbol as the CP. This avoids copying chips outside the X chips as the CP, further avoiding the generation of edges (rising and / or falling edges) in the CP, thus further reducing the interference of the CP on decoding performance, thereby reducing the false detection rate at the receiver and improving communication performance.

[0244] In one possible implementation, when X is odd, the level of the preceding adjacent chip of the X chips in the first OFDM symbol is opposite to the level of the X chips, and the preceding chip of the X chips in the first OFDM symbol is a padding chip. For example, having the preceding chip of the X chips in the first OFDM symbol as a padding chip includes / is replaced by: the preceding chip of the X chips in the first OFDM symbol does not carry bits in the PRDCH. Since the preceding chip of the X chips in the first OFDM symbol is also used as a padding chip when X is odd, and the level of the preceding chip of the X chips can be the same as or opposite to the level of the X chips, when the level of the preceding chip of the X chips can be the same as or opposite to the level of the X chips, the duration of the ON or OFF level at the tail of the first OFDM symbol will not be too long, thereby reducing the bit error rate and improving communication performance.

[0245] Figure 10 illustrates a possible structure of a first signal. As shown in Figure 10, the first signal includes OFDM#5 and OFDM#6, for example, OFDM#6 is the first OFDM symbol. The value of X is 1. The level of the X chips is the same as the level of the first OFDM symbol of the first OFDM symbol, all being ON. The level of the preceding adjacent chip of the X chips of the first OFDM symbol is opposite to the level of the X chips, being OFF. This configuration satisfies the Manchester coding rules, ensuring that the duration of the ON or OFF level at the tail of the first OFDM symbol is not too long, thereby reducing the bit error rate and improving communication performance.

[0246] In one possible implementation, the first OFDM symbol includes / is: chips for carrying a clock capture portion (e.g., CAP) and / or chips for carrying a PRDCH. For example, the first OFDM symbol includes chips for carrying a clock capture portion and chips for carrying a PRDCH. Or the first OFDM symbol includes chips for carrying a PRDCH (e.g., the first OFDM symbol does not include chips for carrying a clock capture portion. Another example is that the first OFDM symbol only includes chips for carrying a PRDCH). A first threshold is associated with the signal carried by the chips in the first OFDM symbol. When the first OFDM symbol includes chips for carrying a clock capture portion and chips for carrying a PRDCH, X chips can belong to either filler chips or partial chips in the CAP. This allows for setting a reasonable first threshold, thereby reducing interference from the CP under different conditions. In one possible implementation, the first threshold is 6, 8, 12, 16, or 24. For example, if the signal carried by the chip in the first OFDM symbol includes PRDCH but does not include the clock capture portion, the first threshold is 6, 8, 12, 16, or 24.

[0247] In one possible implementation, when the first OFDM symbol includes a chip for carrying the clock capture portion and a chip for carrying the PRDCH, the value of the first threshold is less than the value of the first threshold when the first OFDM symbol only includes a chip for carrying the PRDCH. For example, when the first OFDM symbol includes the clock capture portion, the value of the first threshold is less than the value of the first threshold when the first OFDM symbol does not include the clock capture portion and only includes the PRDCH. For instance, when the first OFDM symbol includes the clock capture portion, the value of the first threshold is h#1. When the first OFDM symbol does not include the clock capture portion and only includes the PRDCH, the value of the first threshold is h#2. The value of h#1 is less than h#2. For example, when the first OFDM symbol includes the clock capture portion, the first threshold is set to 6. For example, when the first OFDM symbol does not include the clock capture portion and only includes the PRDCH, the first threshold is set to 8 or 12. For example, when the first OFDM symbol does not include the PRDCH and only includes the clock capture portion, the first threshold is set to 6 or 8. These implementations allow for a more reasonable setting of the first threshold.

[0248] In one possible implementation, when the first OFDM symbol includes chips for carrying the clock capture portion and chips for carrying the PRDCH, the value of M in the first OFDM symbol is equal to 24. For example, when the level pattern of the clock capture portion chips is [ON OFF ON OFF], the number of chips in the clock capture portion is 4. The last X chips in the first OFDM symbol are filler chips, where X equals 2. The first OFDM symbol includes 4 chips for the clock capture signal, 2 filler chips, and the remaining M-4-X=18 chips for carrying the PRDCH. In another possible implementation, when the first OFDM symbol only includes chips for carrying the clock capture portion and does not include the PRDCH, the value of M in the first OFDM symbol is equal to 6. For example, when the level pattern of the clock capture portion chips is [ON OFF ON OFF], the number of chips in the clock capture portion is 4. The last X chips in the first OFDM symbol are filler chips, where X equals 2. The first OFDM symbol includes four chips for the clock capture signal, followed by two padding chips (X=2), and no chips are used to carry the PRDCH.

[0249] As can be seen from the above, in implementation method A1, adding the CP operation does not result in a new edge in the signal. The subsequent terminal device can perform a CP removal operation on the received first signal, thereby reducing the interference of CP on decoding performance, thus reducing the false positive rate during receiver detection, and improving communication performance. However, in implementation method A1, when M is a small value (e.g., less than the first threshold), the duration occupied by a single chip is large, resulting in X chips occupying a large amount of time-domain resources. Since these X chips are padding chips (e.g., these X chips do not carry the clock capture portion and PRDCH), the data transmission efficiency is low. For example, when M is 4 and X is 2, the length of each chip is long, potentially leading to a 50% loss in transmission efficiency. To further improve communication performance, this application provides an implementation method in which the network device can flexibly select the implementation method based on the value of M. For example, when M is greater than or equal to the first threshold, the network device can choose to use implementation method A1, thus reducing the interference of CP on decoding performance, thereby reducing the false positive rate during receiver detection, and improving communication performance.

[0250] In implementation A1, in one possible implementation, after the terminal device receives the first signal from the network device, if it determines that M is greater than or equal to a first threshold, the terminal device can perform a skip / drop operation on the CP. Since the last X chips of the first OFDM symbol are padding chips, the terminal device can also perform an operation to discard the last X chips of the first OFDM symbol. This can reduce the decoding complexity on the terminal device side.

[0251] The following provides a possible operation of discarding CP performed on the terminal device side. In this embodiment, the operation of discarding CP by the terminal device may also be called other names, such as CP removal or CP elimination.

[0252] For example, in one possible implementation, the terminal device can use the last edge within each OFDM symbol as a reference time to locate the CP and remove the sampling points contained in the CP. Referring to Figure 6(b) above, for example, the terminal device uses the last edge in OFDM symbol #1 as the reference time. This reference time can also be called the reference clock. The terminal device already knows that the number of sampling points for a single OFDM symbol clock is T. The specific steps for removing the CP by the terminal device are as follows:

[0253] Step 1: The terminal device knows that the number of samples taken for an OFDM symbol clock is T, where T is a positive integer.

[0254] Step 2: The terminal device detects the last edge of the current OFDM symbol (e.g., OFDM symbol #1 in Figure 6(b)) and knows the starting position of the OFDM symbol. The terminal device counts from the starting position of the OFDM symbol to the last edge within the OFDM symbol, and the number of counted sampling points is T'.

[0255] Step 3: The terminal device counts (T-T') sampling points after the last edge (i.e., the reference time), and the obtained position is determined as the end time position of the current OFDM symbol (OFDM symbol #1) and the start position of the next OFDM symbol (including CP) (e.g., OFDM symbol #2 in Figure 6(b)).

[0256] Step 4: Using the starting position of the next OFDM symbol (e.g., OFDM symbol #2 in Figure 6(b)) as a reference, count T. CP Each sample point is removed (or discarded / not processed) from the T sample. CP The first sample point is used as the starting point for the next OFDM symbol (e.g., OFDM symbol #2 in Figure 6(b)). The T CP Each sample point represents the CP removed by the terminal device.

[0257] In one possible implementation, the terminal device can perform a CP removal operation for each OFDM symbol. Each CP removal operation can execute the above scheme. For example, before performing step four above, the terminal device can re-execute step one for the next OFDM symbol to start detecting the next OFDM symbol in order to remove the CP in the next OFDM symbol.

[0258] In another possible implementation, when removing padding chips from an OFDM symbol, the terminal device can determine the position of the padding chips according to a preset rule or a scheme provided by another device. For example, the terminal device can determine that the last X chips in the first OFDM symbol are padding chips, or determine that the last (X+1) chips in the first OFDM symbol are padding chips. The terminal device determines the position of the padding chips in the time domain using a sampling counting scheme, and then removes these padding chips. The relevant scheme is similar to the CP removal operation described above, and will not be elaborated further.

[0259] In this embodiment, the last X chips in the first OFDM symbol refer to the X chips located at the end of the first OFDM symbol in the time domain direction. The last (X+1) chips in the first OFDM symbol refer to the (X+1) chips located at the end of the first OFDM symbol in the time domain direction.

[0260] In implementation A2, the K OFDM symbols include a second OFDM symbol, and M chips in the second OFDM symbol are used to carry the clock capture section and / or PRDCH.

[0261] When M is less than the first threshold, the K OFDM symbols include a second OFDM symbol, and the M chips in the second OFDM symbol are used to carry the clock capture section and / or PRDCH.

[0262] In one possible implementation, the M chips in the second OFDM symbol used to carry the clock capture portion and / or PRDCH may include / be replaced by: the second OFDM symbol does not include padding chips. In another possible implementation, the chip carrying PRDCH in the embodiments of this application may include / be replaced by: the chip carrying the data signal (or data information) in the PRDCH.

[0263] In one possible implementation, the K OFDM symbols include a second OFDM symbol, in which M chips are used to carry the clock capture portion and / or PRDCH. Alternatively, in the K OFDM symbols, each OFDM symbol except the last OFDM symbol may have M chips used to carry the clock capture portion and / or PRDCH.

[0264] In one possible implementation, after receiving the first signal from the network device, if the terminal device determines that M is less than a first threshold, the terminal device can perform a CP discarding operation. Since the second OFDM symbol does not include padding chips, in this implementation, the terminal device does not need to perform a padding chip discarding operation. For a related scheme for the terminal device to perform the CP discarding operation, please refer to the example of the terminal device performing the CP discarding operation described in Implementation A1 above, which will not be repeated here. In this implementation, the terminal device does not need to perform a padding chip removal operation.

[0265] Figure 11 illustrates a possible structure of a first signal. As shown in Figure 11, the first signal includes OFDM#7 and OFDM#8, for example, OFDM#8 is a second OFDM symbol. Figure 11 is illustrated with an M of 4 as an example. The network device copies the level at the tail of the second OFDM symbol as the CP.

[0266] In implementation A2, one possible implementation is that the second OFDM symbol includes / is: chips for carrying the clock capture portion (e.g., CAP) and / or chips for carrying the PRDCH. For example, the second OFDM symbol includes chips for carrying the clock capture portion and chips for carrying the PRDCH. Or the second OFDM symbol includes chips for carrying the PRDCH (e.g., the second OFDM symbol does not include chips for carrying the clock capture portion. Another example is that the second OFDM symbol only includes chips for carrying the PRDCH). Or the second OFDM symbol includes chips for carrying the clock capture portion (e.g., the second OFDM symbol does not include chips for carrying the PRDCH. Another example is that the second OFDM symbol only includes chips for carrying the clock capture portion). A first threshold is associated with the signal carried by the chips in the second OFDM symbol. When the second OFDM symbol includes chips for carrying the clock capture portion and chips for carrying the PRDCH, X chips can belong to either filler chips or partial chips in the CAP. This allows for setting a reasonable first threshold, thereby reducing interference from the CP under different conditions. In one possible implementation, the first threshold is 6, 8, 12, 16, or 24. For example, if the second OFDM symbol includes a chip for carrying the PRDCH but does not include a chip for carrying the clock capture portion, the first threshold is 6, 8, 12, 16, or 24. As another example, the value of the first threshold is less when the second OFDM symbol includes the clock capture portion than when the second OFDM symbol does not include the clock capture portion and only includes the PRDCH. For example, when the second OFDM symbol includes the clock capture portion, the first threshold is set to 6 or 8; when the first OFDM symbol does not include the clock capture portion and only includes the PRDCH, the second threshold is set to 6, 8, 12, 16, or 24. The setting scheme for the first threshold can be found in the setting method of the aforementioned embodiment A1, and is similar, so it will not be described again.

[0267] In implementation A2, the K OFDM symbols include a second OFDM symbol, and M chips in the second OFDM symbol are used to carry the clock capture section and / or PRDCH. That is, the second OFDM symbol may not include padding chips. The terminal device can use the last edge within the OFDM symbol as a reference time to find the position of the CP and remove the sampling points contained in the CP, thereby reducing the interference of the CP on the decoding performance, thereby reducing the false detection rate at the receiver and improving communication performance. However, when M is a large value (e.g., greater than or equal to a first threshold), the duration occupied by a CP may be greater than the duration occupied by a chip. Therefore, the network device may need to copy multiple chips from the first OFDM symbol before the first OFDM symbol as CPs. The edges in these multiple chips may also be copied before the first OFDM symbol as CPs, resulting in the presence of edges in the CP. Due to clock errors, the terminal device may not be able to accurately remove CPs during the CP removal operation, resulting in the edges present in the CP being left in the signal as false edges, leading to errors in the decoding process. To address this issue, this application provides a solution where, when M is less than a first threshold, the network device can choose to use implementation method A2. This reduces the interference of CPs on decoding performance, thereby lowering the false detection rate at the receiver, and also improves data transmission efficiency. It can be seen that this implementation method, which flexibly selects the implementation method based on the value of M, can balance the false detection rate at the receiver and transmission efficiency, thereby improving overall communication performance.

[0268] In this embodiment, the case where M equals the first threshold can be flexibly set. For example, when M equals the first threshold, the network device can also execute the above-described implementation method A2. For example, when M is greater than the first threshold, the K OFDM symbols, including the first OFDM symbol, satisfy the following: When K > 1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip in the first OFDM symbol, or the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the preceding OFDM symbol; or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF; When K = 1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip of the first OFDM symbol, or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF. When M is less than or equal to the first threshold, the K OFDM symbols include a second OFDM symbol, and M chips in the second OFDM symbol are used to carry the clock capture section and / or PRDCH. Correspondingly, after receiving the first signal from the network device, if the terminal device determines that M is greater than the first threshold, the terminal device can perform a CP discarding operation, discarding the CP and the last X chips of the first OFDM symbol. After receiving the first signal from the network device, if the terminal device determines that M is less than or equal to the first threshold, the terminal device can perform a CP discarding operation. The remaining details are as described in the aforementioned scheme and will not be repeated here.

[0269] In step 701, in another possible implementation, to reduce the interference of CP on decoding performance, this application embodiment exemplifies two possible implementations through the following implementations B1 and B2. For example, in implementation B1, the number of chips used to carry the PRDCH in the first OFDM symbol of the K OFDM symbols is odd. In implementation B2, the number of chips used to carry the PRDCH in the first OFDM symbol of the K OFDM symbols is even.

[0270] In implementation B1, the number of chips used to carry the PRDCH in the first OFDM symbol of the K OFDM symbols is odd.

[0271] For example, the English description of the implementation scheme B1 can be: "odd number of chips of PRDCH is transmitted in the first OFDM symbols".

[0272] In the solutions provided in this application, the network device can flexibly choose the implementation method that can be used according to the actual situation. For example, the network device uses the solution of implementation method B1 when the first condition is met, and uses the solution of implementation method B2 when the second condition is met. The description of the first condition and the second condition can be found in the foregoing content and will not be repeated. The following description uses the example of the first condition including M being greater than or equal to the first threshold and the second condition including M being less than the first threshold. In practical applications, "M being greater than or equal to the first threshold" in this application embodiment can also be replaced with other examples of the first condition, and "M being less than the first threshold" in this application embodiment can also be replaced with other examples of the second condition.

[0273] For example, when M is greater than or equal to the first threshold, the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is P, where P < M and P is an odd number. The number of chips used to carry the PRDCH in the remaining OFDM symbols out of the K OFDM symbols (excluding the first OFDM symbol) is M. For example, in the scheme provided in the embodiments of this application, M is an even number, such as M being one of {2, 4, 6, 8, 12, 16, 24, 32}.

[0274] In one possible implementation, when M is greater than or equal to a first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture section, and the number of chips used to carry the clock capture section in the first OFDM symbol among the K OFDM symbols is odd. Since the sum of two odd numbers is even, the number of chips in the first OFDM symbol among the K OFDM symbols can be even, thus satisfying the requirement that M is defined as an even number.

[0275] Figure 12 illustrates a possible structure of a first signal, which includes OFDM#9 and OFDM#10. Figure 12(a) shows a possible structure of the first signal without a CP, and Figure 12(b) shows a possible structure of the first signal with a CP. As shown in Figure 12, since the number P of chips used to carry the PRDCH in the first OFDM symbol out of K OFDM symbols is odd, the voltage levels before and after the CP insertion point are opposite—one is ON, and the other is OFF. When the network device inserts a CP, regardless of whether the inserted chip is high, low, or includes an edge, the voltage level of that part will not have an additional edge. That is, in this scheme, adding a CP will not result in an additional edge. The subsequent terminal device can perform a CP removal operation on the received first signal, thereby reducing the interference of the CP on decoding performance, reducing the false detection rate at the receiver, and improving communication performance.

[0276] In one possible implementation, one (at least one, or either) OFDM symbol in the first signal includes / is: a chip for carrying a clock capture section (e.g., CAP) and / or a chip for carrying a PRDCH. For example, the first OFDM symbol of the first signal includes a chip for carrying CAP, the number of chips occupied by CAP is odd, for example, the number of chips occupied by CAP is 3, and a possible level pattern (or ON / OFF pattern) of CAP is {101}.

[0277] The first threshold is associated with the signal carried by the chips in the K OFDM symbols. This allows for setting a reasonable first threshold, thereby reducing interference from the CP under different conditions. In one possible implementation, the first threshold is 6, 8, 12, 16, or 24. For example, if the K OFDM symbols include chips for carrying the PRDCH but exclude chips for carrying the clock capture portion, the first threshold is 6, 8, 12, 16, or 24. As another example, the value of the first threshold is lower when the OFDM symbol of the first signal includes the clock capture portion than when the OFDM symbol of the first signal does not include the clock capture portion and only includes the PRDCH. For example, when the OFDM symbol of the first signal includes the clock capture portion, the first threshold is set to 6. For example, when the OFDM symbol of the first signal does not include the clock capture portion and only includes the PRDCH, the first threshold is set to 8 or 12. Related schemes can be found in the foregoing description; the schemes are similar and will not be repeated here. In one possible implementation, in implementation B1, after the terminal device receives the first signal from the network device, if it determines that M is greater than or equal to the first threshold, the terminal device can perform a CP discarding operation. For a relevant scheme for the terminal device to perform the CP discarding operation, please refer to the example of the terminal device performing the CP discarding operation described in implementation A1 above, and it will not be described again. In this implementation, the terminal device does not need to perform a padding chip removal operation.

[0278] In implementation B1, the number of chips used to carry the PRDCH in the first OFDM symbol out of the K OFDM symbols is odd. Therefore, when the network device adds a CP to the first signal, it can add the CP at the edge (rising or falling edge) of the signal. In this case, regardless of whether the level of the chip copied by the network device is high, low, or includes an edge portion, this portion of the level will not have an additional edge. That is, in this scheme, adding a CP will not result in an additional edge. Subsequently, the terminal device can perform a CP removal operation on the received first signal, thereby reducing the interference of CP on decoding performance, thereby reducing the false judgment rate during receiver detection, and thus improving communication performance. However, when M is a small value (e.g., less than the first threshold), the length of a chip is long, and the edge of the OFDM symbol is located in the time portion occupied by the CP. This edge may be at the beginning or end of the CP. Therefore, when the terminal device detects, the position of the edge in the time portion occupied by the CP is uncertain, and the terminal device may make a false judgment, which will lead to a decrease in communication performance. To reduce the impact of CP on decoding, this application provides an implementation method in which the network device can flexibly select the implementation method based on the value of M. For example, when M is greater than or equal to a first threshold, the network device can choose to use the above-described implementation method B1. In this way, the interference of CP on decoding performance can be reduced, thereby reducing the false detection rate at the receiving end and improving communication performance.

[0279] In implementation B2, the number of chips used to carry the PRDCH in the first OFDM symbol of the K OFDM symbols is an even number.

[0280] For example, if M is less than the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol out of K OFDM symbols is N, N≤M, and N is an even number. The number of chips used to carry PRDCH in the OFDM symbols other than the first OFDM symbol out of K OFDM symbols is M.

[0281] In one possible implementation, when M is less than a first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture section, and the number of chips used to carry the clock capture section in the first OFDM symbol among the K OFDM symbols is even. Since the sum of even numbers is even, the number of chips in the first OFDM symbol among the K OFDM symbols can be even, thus satisfying the requirement that M is defined as an even number.

[0282] In another possible implementation, the scheme of implementation B2 can be the same as that of implementation A2 described above.

[0283] In implementation B2, in one possible implementation, one (at least one, or any) OFDM symbol in the first signal includes / is: a chip for carrying a clock capture section (e.g., CAP) and / or a chip for carrying a PRDCH. For example, the first OFDM symbol of the first signal includes a chip for carrying CAP, the number of chips occupied by CAP is even, for example, the number of chips occupied by CAP is 4, and a possible level pattern (or ON / OFF pattern) of CAP is {1010}.

[0284] The first threshold is associated with the signal carried by the chip in the K OFDM symbols. This allows for setting a reasonable first threshold, thereby reducing interference from the CP under different conditions. These implementations can provide a more reasonable first threshold. In one possible implementation, the first threshold is 6, 8, 12, 16, or 24. For example, if the signal carried by the chip in the K OFDM symbols includes PRDCH but excludes the clock capture portion, the first threshold is 6, 8, 12, 16, or 24. As another example, the value of the first threshold is less when the OFDM symbol of the first signal includes the clock capture portion than when the OFDM symbol of the first signal excludes the clock capture portion and only includes PRDCH. For example, when the OFDM symbol of the first signal includes the clock capture portion, the first threshold is set to 6. For example, when the OFDM symbol of the first signal excludes the clock capture portion and only includes PRDCH, the first threshold is set to 8 or 12. Related schemes can be found in the foregoing description; the schemes are similar and will not be repeated here. In one possible implementation, in implementation B1, after the terminal device receives the first signal from the network device, if it determines that M is greater than or equal to the first threshold, the terminal device can perform a CP discarding operation. For a relevant scheme for the terminal device to perform the CP discarding operation, please refer to the example of the terminal device performing the CP discarding operation described in implementation A1 above, and it will not be described again. In this implementation, the terminal device does not need to perform a padding chip removal operation.

[0285] In implementation B2, the number of chips used to carry the PRDCH in the first OFDM symbol out of K OFDM symbols is even. The terminal device can use the last edge within the OFDM symbol as a reference time to find the position of the CP and remove the sampling points contained in the CP, thereby reducing the interference of the CP on the decoding performance, reducing the false detection rate at the receiver, and improving communication performance. In implementation B2, when M is a large value (e.g., greater than or equal to the first threshold), the duration occupied by a CP may be greater than the duration occupied by a chip. Therefore, the network device may need to copy multiple chips in an OFDM symbol before the OFDM symbol as CPs. The edges in these multiple chips may also be copied before the OFDM symbol as CPs, resulting in edges in the CP. Due to clock errors, the terminal device may not be able to remove the CP accurately when performing the CP removal operation, resulting in the edges in the CP being left in the signal, becoming false edges in the signal, which in turn causes errors in the decoding process of the terminal device. To further improve communication performance, this application provides an implementation method where, when M is less than a first threshold, the network device can choose to use the above-described implementation method B2, thereby reducing the false positive rate during receiver detection and improving communication performance. It can be seen that this implementation method, which flexibly selects the implementation method based on the value of M, can balance the false positive rate during receiver detection and transmission efficiency, thereby improving overall communication performance.

[0286] In the above embodiments, the case where M equals the first threshold can be flexibly set. For example, if M equals the first threshold, the network device can also execute the above embodiment B2. For example, if M is greater than the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol out of K OFDM symbols is P, and the number of chips used to carry PRDCH in the other OFDM symbols out of K OFDM symbols is M. If M is less than or equal to the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol out of K OFDM symbols is N, and the number of chips used to carry PRDCH in the other OFDM symbols out of K OFDM symbols is M. The remaining details can be found in the aforementioned scheme and will not be repeated here.

[0287] Figure 13 illustrates a schematic diagram of SNR and BLER using various implementation methods. The unit of SNR is decibel (dB). Figure 13(a) is illustrated with an example of M=6, and Figure 13(b) is illustrated with an example of M=24.

[0288] The scheme using only Alt M1 in Figure 13 can be understood as the terminal device performing a CP removal operation on the received data. For example, the network device sends a first signal through the scheme provided in the above-described embodiment A2 or embodiment B2, and the terminal device performs a CP removal operation to remove the CP in the first signal.

[0289] The scheme in Figure 13 using only Alt M2-1-1 can be understood as simply adding padding chips to the OFDM symbol using the scheme provided in Implementation A1 above, but the terminal device does not perform the CP removal operation on the received signal. The scheme in Figure 13 using both Alt M2-1-1 and Alt M1 can be understood as adding padding chips to the OFDM symbol using the scheme provided in Implementation A1 above, and the terminal device performs the CP removal operation on the received signal. Optionally, the terminal device may also perform the padding chip removal operation.

[0290] The scheme using only Alt M2-1-2 in Figure 13 can be understood as the network device setting the number of PRDCH-carrying chips in the first OFDM symbol of the first signal to an odd number using the scheme provided in Embodiment B1 above, but the terminal device does not perform the CP removal operation on the received signal. The scheme using both Alt M2-1-2 and Alt M1 in Figure 13 can be understood as the network device setting the number of PRDCH-carrying chips in the first OFDM symbol of the first signal to an odd number using the scheme provided in Embodiment B1 above, and the terminal device performing the CP removal operation on the received signal.

[0291] As shown in Figure 13(a), when the value of M is small, for example, when M is less than the first threshold and M = 6, the scheme using only Alt M1 (Implementation A2 or Implementation B2) (i.e., line #5) also has the best performance gain. Furthermore, this scheme does not require adding padding chips to the OFDM symbol, thus further improving data transmission efficiency.

[0292] As shown in Figure 13(b), when the value of M is large, for example, when M is greater than the first threshold and M = 24, the scheme using only Alt M1 (Implementation A2 or Implementation B2) has poor performance gain (i.e., line #6 in the figure; for example, under the same SNR, the BLER of this scheme is smaller). The scheme using AltM2-1-1 (Implementation A1) and AltM1 has better performance gain (i.e., line #7 in the figure), and the scheme using AltM2-1-2 (Implementation B1) and AltM1 has better performance gain (i.e., line #8 in the figure). That is, when the value of M is large, compared to the method of only performing Alt M1 without Alt M2-1-1 (line #6), the scheme combining Alt M2-1-1 and Alt M1 (line #7) has a 1-2 dB downlink transmission performance gain. In this case, the method of only performing Alt M1 CP removal (line #6) is the poorest performing scheme. For example, when M is a large value, compared to the method of removing CP only by Alt M1 without Alt M2-1-2 (line #6), the scheme combining Alt M2-1-2 and Alt M1 (line #8) has more downlink transmission performance gain. In this case, the method of removing CP only by Alt M1 (line #6) is a poor performance scheme.

[0293] As can be seen from the above, the solution provided in this application embodiment can flexibly select the specific setting scheme of the first signal according to the M value and other content, so that the transmission performance and transmission efficiency of the signal under each M value range can be taken into account, thereby improving the communication performance.

[0294] It is understood that, in order to achieve the functions in the above embodiments, the terminal device or network device may include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware, computer software, or a combination of hardware and computer software. Whether a particular function is executed in hardware, software, or a combination of software and hardware depends on the specific application scenario and design constraints of the technical solution.

[0295] Based on the same concept, Figures 14 and 15 are schematic diagrams of possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of network devices or terminal devices in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device may be the terminal device involved in Figure 7, a chip (system) inside the terminal device, a network device, or a chip (system) inside the network device.

[0296] As shown in Figure 14, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The communication device 1300 is used to implement the functions of the network device or terminal device in the method embodiment shown in Figure 7 above. The transceiver unit 1320 can also be referred to as a communication unit. The transceiver unit 1320 may include a sending unit and a receiving unit.

[0297] When the communication device 1300 is used to implement the function of the network device in the method embodiment shown in FIG7, in one possible implementation, the transceiver unit 1320 is used to send a first signal.

[0298] When the communication device 1300 is used to implement the function of the network device in the method embodiment shown in FIG7, in one possible implementation, the processing unit 1310 is used to add CP to the first signal.

[0299] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG7, in one possible implementation, the transceiver unit 1320 is used to receive the first signal.

[0300] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG7, in one possible implementation, the processing unit 1310 is used to perform a CP removal operation on the first signal.

[0301] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG7, in one possible implementation, if the OFDM symbol in the first signal includes a padding chip, the processing unit 1310 is also used to perform a padding chip removal operation on the first signal.

[0302] For a more detailed description of the processing unit 1310 and the transceiver unit 1320, please refer to the relevant description in the method embodiment shown in FIG7.

[0303] As shown in Figure 15, the communication device 1400 includes a processor 1410 and an interface circuit 1420. The processor 1410 and the interface circuit 1420 are coupled to each other. It can be understood that the interface circuit 1420 can be a transceiver or an input / output interface. The transceiver includes a transmitter and a receiver; the transmitter can be used to send information, and the receiver can be used to receive information. Other functions can be implemented by the processor. The input / output interface is used to input and / or output information; output can be understood as sending, and input can be understood as receiving. Other functions can be implemented by the processor. Optionally, the communication device 1400 may also include a memory 1430 for storing instructions executed by the processor 1410, or storing input data required by the processor 1410 to execute instructions, or storing data generated after the processor 1410 executes instructions.

[0304] When the communication device 1400 is used to implement the method shown in FIG7, the processor 1410 is used to implement the function of the processing unit 1310, and the interface circuit 1420 is used to implement the function of the transceiver unit 1320.

[0305] When the aforementioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal device in the above method embodiments. The terminal chip receives information from the base station, which can be understood as the information being first received by other modules in the terminal (such as an RF module or antenna), and then sent to the terminal chip by these modules. The terminal chip sends information to the base station, which can be understood as the information being first sent to other modules in the terminal (such as an RF module or antenna), and then sent to the base station by these modules.

[0306] When the aforementioned communication device is a chip applied to a base station, the base station chip implements the functions of the network device in the above method embodiments. The base station chip receives information from the terminal, which can be understood as the information being first received by other modules in the base station (such as an RF module or antenna), and then sent to the base station chip by these modules. The base station chip sends information to the terminal, which can be understood as the information being sent down to other modules in the base station (such as an RF module or antenna), and then sent to the terminal by these modules.

[0307] Based on the same concept, embodiments of this application provide a system, which includes a network device and a terminal device.

[0308] Based on the same concept, embodiments of this application provide a chip system, which includes at least one processor and an interface circuit. The interface circuit and at least one processor are interconnected by a line. The processor executes a computer program (also referred to as code or instructions) to enable any of the possible implementations in FIG7 to be executed.

[0309] Based on the same concept, this application provides a computer program product, which includes a computer program (also referred to as code or instructions) that, when run, causes a computer to perform any of the possible implementations shown in FIG7.

[0310] Based on the same concept, embodiments of this application provide a computer-readable storage medium storing a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform any of the possible implementations shown in FIG7.

[0311] In this application, entity A sends information to entity B, either directly or indirectly through other entities. Similarly, entity B receives information from entity A, either directly or indirectly through other entities. Entities A and B can be RAN nodes or terminals, or modules within RAN nodes or terminals. Information transmission and reception can be between RAN nodes and terminals, such as between a base station and a terminal; between two RAN nodes, such as between a CU and a DU; or between different modules within a single device, such as between a terminal chip and other modules of the terminal, or between a base station chip and other modules of the base station.

[0312] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0313] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, compact disc read-only memory (CD-ROM), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or terminal. The processor and storage medium can also exist as discrete components in the base station or terminal.

[0314] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer programs or instructions. When a computer program or instruction is loaded and executed on a computer, all or part of the processes or functions of the embodiments of this application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, a computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0315] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0316] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character " / " indicates a "division" relationship between the preceding and following related objects. "Including at least one of A, B, or C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0317] It is understood that the various numbers involved in the embodiments of this application (such as the numerical numbers "first" and "second", and the letter numbers "A1, A2", "B1, B2", "C1, C2", etc.) are only for the convenience of description and are not intended to limit the scope of the embodiments of this application. The order of the above-mentioned process numbers does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, include: Identify the first signal; The first signal is transmitted, the first signal comprising K orthogonal frequency division multiplexing (OFDM) symbols, where K is a positive integer, and each of the K OFDM symbols comprises M chips, where M is a positive integer; Wherein, if M is greater than or equal to the first threshold, the K OFDM symbols include the first OFDM symbol: When K > 1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip in the first OFDM symbol, or the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the preceding OFDM symbol; or, the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF, where X is a positive integer, and the last X chips of the first OFDM symbol are filler chips. Alternatively, in the case where K=1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip of the first OFDM symbol; or the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF. When M is less than the first threshold, the K OFDM symbols include a second OFDM symbol, and the M chips in the second OFDM symbol are used to carry the clock capture part and / or the physical reader to the device channel PRDCH.

2. The method as described in claim 1, characterized in that, Also includes: Add a cyclic prefix (CP) to each of the K OFDM symbols.

3. The method as described in claim 1 or 2, characterized in that, The first OFDM symbol is any one of the K OFDM symbols; or, The first OFDM symbol is any one of the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion; or, The first OFDM symbol is the first OFDM symbol among the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion.

4. The method according to any one of claims 1-3, characterized in that, The time length occupied by the X chips is greater than or equal to the time length occupied by the CP.

5. The method according to any one of claims 1-4, characterized in that, When the value of M is 32, the value of X is 3; or, When the value of M is 12, 16, or 24, the value of X is 2; or, When the value of M is 6, 8, or 12, the value of X is 1.

6. The method according to any one of claims 1-5, characterized in that, When the value of X is odd, the level of the preceding adjacent chip of the X chips of the first OFDM symbol is opposite to the level of the X chips, and the preceding chip of the X chips of the first OFDM symbol is a padding chip.

7. The method according to any one of claims 1-6, characterized in that, The first threshold is associated with the signal carried by the chip in the first OFDM symbol, which includes: a chip for carrying a clock capture signal and / or a chip for carrying a PRDCH.

8. The method according to any one of claims 1-7, characterized in that: The first threshold is 6, 8, 12, 16 or 24.

9. A communication method, characterized in that, include: A first signal is transmitted, the first signal comprising K orthogonal frequency division multiplexing (OFDM) symbols, where K is a positive integer, and each of the K OFDM symbols comprises M chips, where M is a positive integer; Wherein, when M is greater than or equal to the first threshold, the number of chips used to carry the physical reader-to-device channel (PRDCH) in the first OFDM symbol among the K OFDM symbols is P, where P < M, and P is an odd number; the number of chips used to carry the PRDCH in the OFDM symbols other than the first OFDM symbol among the K OFDM symbols is M. When M is less than the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol among the K OFDM symbols is N, where N ≤ M and N is an even number. The number of chips used to carry PRDCH in the OFDM symbols other than the first OFDM symbol among the K OFDM symbols is M.

10. The method as described in claim 9, characterized in that, When M is greater than or equal to the first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture signal, and the number of chips used to carry the clock capture signal in the first OFDM symbol among the K OFDM symbols is odd.

11. The method as described in claim 9, characterized in that, When M is less than the first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture signal, and the number of chips used to carry the clock capture signal in the first OFDM symbol among the K OFDM symbols is even.

12. The method according to any one of claims 9-11, characterized in that, The first threshold is associated with the signal carried by the chip in the K OFDM symbols, which include: chips for carrying clock capture signals and / or chips for carrying PRDCH.

13. The method according to any one of claims 9-12, characterized in that: The first threshold is 6, 8, 12, 16 or 24.

14. A communication method, characterized in that, include: Receive a first signal, the first signal comprising K orthogonal frequency division multiplexing (OFDM) symbols, where K is a positive integer, and each of the K OFDM symbols comprises M chips, where M is a positive integer; Detect the first signal; Wherein, if M is greater than or equal to the first threshold, the K OFDM symbols include the first OFDM symbol: When K > 1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip in the first OFDM symbol, or the level of the last X chips of the first OFDM symbol is the same as the level of the last chip of the preceding OFDM symbol; or, the level of each of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF, where X is a positive integer, and the last X chips of the first OFDM symbol are filler chips; When K=1: the level of the last X chips of the first OFDM symbol is the same as the level of the first chip of the first OFDM symbol; or the level of each chip of the last X chips of the first OFDM symbol is ON or the level of each chip is OFF. When M is less than the first threshold, the K OFDM symbols include a second OFDM symbol, and the M chips in the second OFDM symbol are used to carry clock capture signals and / or physical reader to device channel PRDCH.

15. The method as described in claim 14, characterized in that, The method further includes: If M is greater than or equal to the first threshold, remove the CP and the X chips from the first signal; or, If M is greater than or equal to the first threshold, CP in the first signal is removed.

16. The method as described in claim 14 or 15, characterized in that, The first OFDM symbol is any one of the K OFDM symbols; or, The first OFDM symbol is any one of the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion; or, The first OFDM symbol is the first OFDM symbol among the K OFDM symbols excluding the first S OFDM symbols, where S is a positive integer, and the S OFDM symbols are used to carry the start indication portion.

17. The method according to any one of claims 14-16, characterized in that, The time length occupied by the X chips is greater than or equal to the time length occupied by the CP.

18. The method according to any one of claims 14-17, characterized in that, When the value of M is 32, the value of X is 3; or, When the value of M is 12, 16, or 24, the value of X is 2; or, When the value of M is 6, 8, or 12, the value of X is 1.

19. The method according to any one of claims 14-18, characterized in that, When the value of X is odd, the level of the preceding adjacent chip of the X chips of the first OFDM symbol is opposite to the level of the X chips, and the preceding chip of the X chips of the first OFDM symbol is a padding chip.

20. The method according to any one of claims 14-19, characterized in that, The first threshold is associated with the signal carried by the chip in the first OFDM symbol, which includes: a chip for carrying a clock capture signal and / or a chip for carrying a PRDCH.

21. The method according to any one of claims 14-20, characterized in that: The first threshold is 6, 8, 12, 16 or 24.

22. A communication method, characterized in that, include: Receive a first signal, the first signal comprising K orthogonal frequency division multiplexing (OFDM) symbols, where K is a positive integer, and each of the K OFDM symbols comprises M chips, where M is a positive integer; Wherein, when M is greater than or equal to the first threshold, the number of chips used to carry the physical reader-to-device channel (PRDCH) in the first OFDM symbol among the K OFDM symbols is P, where P < M, and P is an odd number; the number of chips used to carry the PRDCH in the OFDM symbols other than the first OFDM symbol among the K OFDM symbols is M. When M is less than the first threshold, the number of chips used to carry PRDCH in the first OFDM symbol among the K OFDM symbols is N, where N ≤ M and N is an even number. The number of chips used to carry PRDCH in the OFDM symbols other than the first OFDM symbol among the K OFDM symbols is M.

23. The method as described in claim 22, characterized in that, When M is greater than or equal to the first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture signal, and the number of chips used to carry the clock capture signal in the first OFDM symbol among the K OFDM symbols is odd.

24. The method as described in claim 22, characterized in that, When M is less than the first threshold, the first OFDM symbol among the K OFDM symbols further includes a clock capture signal, and the number of chips used to carry the clock capture signal in the first OFDM symbol among the K OFDM symbols is even.

25. The method according to any one of claims 22-24, characterized in that, The first threshold is associated with the signal carried by the chip in the K OFDM symbols, which include: a clock capture signal and a PRDCH; or a chip for carrying the clock capture signal and / or a chip for carrying the PRDCH.

26. The method according to any one of claims 22-25, characterized in that: The first threshold is 6, 8, 12, 16 or 24.

27. A communication device, characterized in that, Includes modules for performing the method as described in any one of claims 1 to 26.

28. A communication device, characterized in that, It includes at least one processor, which implements the method as described in any one of claims 1 to 26 by means of logic circuits or by executing computer programs or instructions.

29. The communication device as claimed in claim 28, characterized in that, It also includes a memory for storing the computer program or instructions.

30. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1 to 26.

31. A computer program product, characterized in that, The computer program product stores a computer program, the computer program including program instructions, which, when executed by a computer, cause the computer to perform the method as described in any one of claims 1 to 26.

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