Signal design for backscatter communication

Abstract

An example discloses a method of transmitting data bits by a wireless device by communicating or absorbing an incoming signal, the method comprising: for a data bit having a value of zero, obtaining a first pattern comprising a number of chips having a predetermined duration; obtaining, for a data bit having a value of one, a second pattern comprising a number of chips having a predetermined duration; and passing or absorbing the incoming signal according to the first mode or the second mode during each chip, where the first mode and the second mode are selected to have an equal number of chips during which the incoming signal is absorbed. Further, examples disclose a method of receiving data bits.

Description

Technical Field

[0001] Various examples generally relate to transmitting data using backscatter communications. Background Art

[0002] Modern data transmission relies heavily on wireless communication. Traditional radio communication requires the transmitting device to use components such as digital-to-analog converters (DACs), mixers, oscillators, and power amplifiers to generate radio signals, and the receiving device is required to use components of low-noise amplifiers, mixers, oscillators, and analog-to-digital converters (ADCs) to receive radio signals. Typically, the devices involved in wireless communication are battery-powered, and the aforementioned components for wireless communication consume a large amount of energy provided by the battery. Therefore, the battery will have to be recharged or replaced regularly. With the increase in the number of battery-powered devices involved in wireless communication, this may no longer be feasible. For example, one trillion Internet of Things (IoT) devices with a 10-year battery life in the world already means that 27.4 billion batteries will have to be replaced every day. However, in several use cases, even a 10-year battery life cannot be achieved with known technology.

[0003] Furthermore, battery recycling remains inadequate. In 2018, 191,000 tonnes of portable batteries were sold in the EU, but less than half of that amount (i.e. 88,000 tonnes of used portable batteries) were collected as waste for recycling. Given the limited natural resources required for battery production, the demand for new batteries must also be reduced. Summary of the invention

[0004] Hence, there may be a need for data transmission involving less power consumption. Said need has been solved by the subject matter of the independent claims. Advantageous embodiments are described in the dependent claims.

[0005] An example discloses a method for transmitting data bits by passing or absorbing an incoming signal by a wireless device, the method comprising: for a data bit having a value of zero, obtaining a first pattern including a number of code chips having a predetermined duration; for a data bit having a value of one, obtaining a second pattern including a number of code chips having the predetermined duration; and during each code chip, passing or absorbing the incoming signal according to the first pattern or the second pattern, wherein the first pattern and the second pattern are selected to have an equal number of code chips during which the incoming signal is absorbed.

[0006] In addition, an example discloses a method for receiving, by a communication node, data bits transmitted by a wireless device by passing or absorbing an incoming signal, the method comprising: obtaining a third pattern including a number of code chips having a predetermined duration, wherein, if the corresponding code chip of the first pattern associated with a data bit with a value of zero and the corresponding code chip of the second pattern associated with a data bit with a value of one are equal, then the code chip of the third pattern is zero, wherein if the corresponding code chip of the first pattern is greater than the corresponding code chip of the second pattern, then the code chip of the third pattern has a positive sign, wherein if the corresponding code chip of the first pattern is less than the corresponding code chip of the second pattern, then the code chip of the third pattern has a negative sign; and decoding a received pattern representing the data bit based on the third pattern.

[0007] Additionally, examples disclose a wireless device comprising circuitry configured to perform the above method of transmitting data bits and a communication node comprising circuitry configured to perform the above method of receiving data bits. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Backscatter communications are schematically illustrated;

[0009] Figure 2 schematically illustrates a transmission circuit for backscatter communication;

[0010] Figure 3 The transmission mode is schematically shown;

[0011] Figure 4 The modulated channels are schematically shown;

[0012] Figure 5 schematically illustrates a receiving circuit for backscatter communication;

[0013] Figure 6 schematically illustrates a synchronization circuit for backscatter communications;

[0014] Figure 7 Schematically illustrates a receiving circuit for multi-device backscatter communication;

[0015] Figure 8 The relationship between the signal-to-interference ratio and the spreading factor is schematically shown;

[0016] Fig. 9 schematically illustrates transmission data bits; and

[0017] Fig.10 The received data bits are schematically shown. DETAILED DESCRIPTION

[0018] Some examples of the present disclosure generally provide multiple circuits or other electrical devices. All references to circuits and other electrical devices and the functions provided by each are not intended to be limited to the contents shown and described herein. Although specific labels can be assigned to the various circuits or other electrical devices disclosed, such labels are not intended to limit the operating range of circuits and other electrical devices. Based on the desired specific type of electrical implementation, such circuits and other electrical devices can be combined and / or separated from each other in any way. It should be recognized that any circuit or other electrical device disclosed herein may include any number of microcontrollers, graphics processor units (GPUs), integrated circuits, memory devices (e.g., FLASH, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or other suitable variants thereof) and software that works together to perform the operations disclosed herein. In addition, any one or more of the electrical devices may be configured to execute a program code, which is contained in a non-transitory computer-readable medium programmed to perform any number of functions disclosed.

[0019] Hereinafter, examples of the present disclosure will be described in detail with reference to the accompanying drawings. It should be understood that the following description of the embodiments should not be construed as limiting. The scope of the present disclosure is not intended to be limited by the examples or drawings described below, which are considered to be illustrative only.

[0020] The drawings are to be considered as schematic representations, and the elements shown in the drawings are not necessarily shown to scale. Instead, the various elements are represented so that their functions and general purposes become apparent to those skilled in the art. Any connection or coupling between the functional blocks, devices, components or other physical or functional units shown in the drawings or described herein may also be achieved by indirect connection or coupling. Coupling between components may also be established by wireless connection. Functional blocks may be implemented with hardware, firmware, software or a combination thereof.

[0021] Figure 1A typical modern communication environment 100 is shown, including a wireless device 120 and a receiver device 130. The wireless device 120 includes circuitry implemented by a processor 121, a non-volatile memory 122, and an interface 123, which can access and control one or more antennas 124. Similarly, the receiver device 130 includes circuitry implemented by a processor 131, a non-volatile memory 132, and an interface 133, which can access and control one or more antennas 134. As explained previously, modern data transmission relies heavily on wireless communications. Therefore, many RF sources 110 may be present in a typical environment. RF sources may include TV towers, cellular base stations, Bluetooth transmitters, and Wi-Fi access points.

[0022] Modulating and / or reflecting already existing ambient RF signals can allow substantial power savings, rather than using energy-intensive components to generate and transmit radio waves. This approach is also known as backscattering communication (BSC).

[0023] like Figure 1 As shown, the receiver device 130 can receive the signal via the interference channel h j In addition, the receiver device 130 can receive the ambient RF signal via another channel h provided by the wireless device 120. f h b The wireless device 120 can receive the ambient RF signal by backscatter modulation (i.e., by controlling h b ) to affect the channel h f h b In particular, the wireless device 120 may reflect or absorb the f Incoming ambient signals received.

[0024] Figure 2 2 shows a possible circuit 200 of a wireless device 120. The wireless device 120 communicates via a channel h with an antenna 224. f The signal s(t) arriving at the wireless device 120 is received. In response to the data bit d, the wireless device 120 responds to the pattern p d It is provided that the antenna 224 is connected to the ground 225 (ie, p d (t) = 0) or connected to the load 226 (i.e., p d (t) = 1) to reflect or absorb the incoming signal h _ f(t)s(t). Therefore, the wireless device 120 can transmit the signal ηp d (t)h f (t)s(t), where the term η indicates the reflection efficiency. The mode p can be selected based on the data bit value of the data bit d. d(t).

[0025] For modulation applied to Figure 2 The circuitry of the wireless device 120 for loading the antenna 224 is shown to consist of only a switch 227 and a load (ie, impedance) 226. Thus, the circuitry can be of low complexity and very energy efficient.

[0026] Figure 3 A first pattern p0(t) associated with a data bit value of zero and a second pattern p1(t) associated with a data bit value of one are shown. Both patterns include L chips. The term "chip" may refer to a certain time interval. A chip has a predetermined duration T c Therefore, the total duration of the pattern, which can also be called the bit time, is T b =LT c The first transmission mode p0(t) and the second transmission mode p1(t) are selected to have an equal number of chips with level zero (level 0). This means that the number of chips with level one (level 1) is also the same for the first transmission mode p0(t) and the second transmission mode p1(t). The first mode p0(t) and / or the second mode p1(t) may be constructed as an on-off keying (OOK) sequence with level one and level zero.

[0027] Figure 4 It shows that under the assumption of unmodulated channel h i (t) changes in bit time T b =LT c The modulation factor m(t) experienced by the receiver device 130 in the case where the period is negligible. The modulation factor m(t) is shown for the case where the wireless device 103 applies the first mode p0(t) and the case where the wireless device 103 applies the second mode p1(t).

[0028] The modulation factor m(t) can be expressed as

[0029] m(t)=h i (t)+η·h f (t)h b (t)p d (t)

[0030] Among them, h i represents the unmodulated interference channel, η is the reflection efficiency of the wireless device 120, and h f (t) is the channel between the ambient source 110 and the wireless device 120, h b (t) is the channel between the wireless device 120 and the receiver device 130, and p d (t) is the mode used by the wireless device 120.

[0031] Therefore, the receiver device 130 may receive the following signal

[0032] r(t)=(h i (t)+η·h f (t)h b (t)p d (t))s(t)

[0033] Figure 5 1 shows a method in which the receiver device 130 receives the data bit d transmitted by the wireless device 120. Specifically, Figure 5 The decoding is shown by the receiver device 130 ( Figure 1 )The received signal r(t).

[0034] At 501, the time duration T c The received signal r(t) is sampled to obtain a received pattern r(n) representing a data bit d. At 502, the elements of the received pattern r(n) may be transformed to obtain only positive values ​​(e.g., the elements may be squared or the absolute value of the elements may be determined), and then at block 503, multiplied by corresponding elements of a third pattern q(n). If Then the elements of the third pattern q(n) can be defined as follows:

[0035]

[0036] Otherwise, the negation is defined as above.

[0037] This may produce a fourth pattern y(n). At 504, the sum of all L members of the fourth pattern y(n) may be calculated:

[0038]

[0039] At 505, the result may be compared to zero to obtain the value of the data bit:

[0040]

[0041] If the sum is less than zero, the data bit value may be decoded as zero. Correspondingly, if the sum is greater than zero, the data bit value may be decoded as one.

[0042] In particular, for the first transmission mode p0(t) and the second transmission mode p1(t), the same number of chips with level zero is selected, which allows a particularly simple method for decoding the received signal. In particular, it may allow the need for an estimate of the detection threshold of a maximum likelihood (ML) detector at the receiver device to be eliminated. For this purpose, it may also allow the pilot information to be omitted. All of this may contribute to a very simple and low-power detection scheme.

[0043] The proposed transmission of a single data bit across L chips may allow for substantial processing gain at the receiver device, which helps overcome the high interference levels associated with backscatter communications.The processing gain may be adjusted appropriately by selecting the value of L.

[0044] In some examples, transmission patterns p0(t) and p1(t) may be selected to have a peak-to-valley autocorrelation ratio of at least L / 2. This may allow the use of transmission patterns with the same bit time T b =L·T c (ie, the same number of L chips) of patterns p0(t) and p1(t).

[0045] Figure 6 The schematic diagram shows a circuit that can be used by a receiver device for bit synchronization. At 601, a predetermined time duration T c The received signal r(t) is sampled to obtain a received pattern r(n) representing a data bit d. At 602, the elements of the received pattern r(n) may be transformed to obtain only positive values ​​(e.g., the elements may be squared or the absolute values ​​of the elements may be determined). At 603, the matched filter p may be d (L-1-n) is applied to the received pattern y(n). After the filter is applied, the peak may be detected (604) to obtain the bit synchronization signal bit sync.

[0046] A plurality of wireless devices capable of transmitting data bits d using backscattering techniques may be required. A third transmission pattern p2(t) and a fourth transmission pattern p3(t) having L chips are used for another wireless device, wherein the peak-to-valley cross-correlation ratio with the first transmission pattern p0(t) and the second transmission pattern p1(t) is at least Identification of different wireless devices and multiple access may be allowed.

[0047] Figure 7 A method for receiving data bits d transmitted by a plurality of wireless devices by a receiver device is shown, which method is similar to that of reference Figure 5 Describe the method.

[0048] In summary, examples disclosed herein may allow energy-efficient transmission of data using ambient RF signals s(t) even when the corresponding RF sources are unpredictable and uncontrollable.

[0049] At 701, the time duration T c The received signal r(t) is sampled to obtain a received pattern r(n) representing a data bit d received from one of the plurality of wireless devices. At 702, the elements of the received pattern r(n) may be transformed to obtain only positive values ​​(e.g., the elements may be squared or the absolute values ​​of the elements may be determined), and then at 703, compared to the third pattern q k (n), where k∈1...K. If Then the elements of the third pattern qk(n) can be defined as follows:

[0050]

[0051] Otherwise, the inverse is defined as above.

[0052] This may lead to a fourth mode y k (n). The sum of all L members of the fourth mode may be calculated at 704:

[0053]

[0054] The result can be compared to zero to obtain the data bit d k Values:

[0055]

[0056] If the sum is less than zero, the data bit value may be decoded as zero. Correspondingly, if the sum is greater than zero, the data bit value may be decoded as one.

[0057] Similarly, if the modes used in different receiver devices are chosen so that their peak-to-trough cross-correlation ratio is at least Transmission patterns of the same length L can then be used to address different receiver devices.

[0058] Examples may allow different p to be used for wireless device identification and receiver device addressing d For example, the mode p of the corresponding receiving device can be used to address d，rx (n) to encode bit information b0, b1, ..., b N One or more information bits b0…b i-1 , and can be transmitted through a unique p for the corresponding wireless device d，tx (n) to encode all other information bits bi ...b N .

[0059] Figure 8 The results of theoretical calculations verified by simulation are shown, showing the relationship between the signal-to-interference ratio and the required spreading factor for three different original bit error rates (0.1, 0.01 and 0.001) assuming a non-fading environment. The spreading factor corresponds to each transmission mode p d (t) is a predetermined number L of chips.

[0060] For example, in an environment with a signal-to-interference ratio of -20 dB, each transmission mode p d (t) About 1300 chips may be sufficient to achieve a bit error rate of 0.01.

[0061] The backscatter communication techniques described herein may be particularly useful in relatively static environments.

[0062] The ambient signal for the BSC may have a different carrier frequency. When the carrier frequency of the ambient RF signal expected to be used for the BSC is lower than 2.5 GHz, the predetermined duration T of the chip is selected to be less than 180 ms. c (T c When the carrier frequency of the ambient RF signal expected to be used for the BSC is below 7 GHz, the predetermined duration T of the chip is selected to be less than 60 ms. c (T c When the carrier frequency of the ambient RF signal expected to be used for the BSC is below 17 GHz, the predetermined duration T of the chip is selected to be less than 24 ms. c (T c When the carrier frequency of the ambient RF signal expected to be used for the BSC is below 30 GHz, the predetermined duration T of the chip is selected to be less than 13 ms. c (T c When the carrier frequency of the ambient RF signal expected to be used for the BSC is below 40 GHz, the predetermined duration T of the chip is selected to be less than 9 ms. c (T c When the carrier frequency of the ambient RF signal expected to be used for the BSC is below 65 GHz, the predetermined duration T of the chip is selected to be less than 6 ms. c (T c When the carrier frequency of the ambient RF signal expected to be used for the BSC is below 65 GHz, the predetermined duration T of the chip is selected to be less than 5 ms. c (T c<5ms) may be particularly useful.

[0063] The predetermined duration T of the chip c Larger values ​​of may require fewer switching of the radio, resulting in lower energy consumption of the wireless device.

[0064] If a very short delay spread as specified by 3GPP is expected, a predetermined duration T greater than 10 ns is selected. c (T c If a short delay spread as specified by 3GPP is expected, a predetermined duration T greater than 30 ns is selected. c (T c If the nominal delay spread specified by 3GPP is expected, a predetermined duration T greater than 100 nS is selected. c (T c If a long delay spread as specified by 3GPP is expected, a predetermined duration T greater than 300 ns is selected. c (T c If a very long delay spread as specified by 3GPP is expected, a predetermined duration T greater than 1000 ns is selected. c (T c <300ns) may be useful.

[0065] Scheduled duration T c Smaller values ​​of can allow the backscattered signal to be spread more over the available bandwidth, resulting in more efficient use of the available spectrum.

[0066] Preferably, the predetermined duration T c is chosen to be much longer than the delay spread of the channel used for the BSC, and much shorter than the coherence time of the channel.

[0067] For example, the predetermined duration T c can be chosen to satisfy the following

[0068] 0.5μs<<T c <<200msec

[0069] Such a predetermined duration T c It may be suitable in scenarios when the environment is represented by the standardized Extended Pedestrian A (EPA) channel model. In the EPA model, the Doppler spread is 5 Hz, corresponding to a coherence time of about 200 ms and a delay spread of less than 500 ns.

[0070] Fig. 9 A method is shown in which a wireless device transmits (particularly reflects or retransmits) or absorbs an incoming signal (particularly an incoming ambient signal) to transmit data.

[0071] At 901, the method provides that, for a data bit having a value of zero, obtaining a c ) of a first pattern (p0) of a number (L) of chips. At 902, the method provides for obtaining, for a data bit having a value of one, a first pattern (p0) having a predetermined duration (T c ) of a second pattern (p1) of a number (L) of chips. In another example, the method may provide for obtaining the second pattern (p1) before obtaining the first pattern (p0).

[0072] Obtaining the first pattern and / or the second pattern may include obtaining the pattern from a codebook. For example, obtaining the first pattern and / or the second pattern may include reading the pattern from a memory of the wireless device. Obtaining the first pattern and / or the second pattern may also include obtaining (e.g., receiving) a message indicating the pattern associated with the corresponding data bit value from another communication device. The message may be broadcast or specifically addressed to the wireless device.

[0073] At 903, the method provides for passing or absorbing incoming signals according to a first pattern or a second pattern during each chip.For example, if the value of the data bit to be transmitted is zero, the wireless device will pass and absorb incoming signals according to the first pattern.

[0074] The first mode and the second mode are selected to have an equal number of chips during which the incoming signal is absorbed.

[0075] Transmitting can include reflecting or forwarding an incoming signal. For example, a reference Figure 2 Forwarding can refer to situations where an incoming signal can pass through a wireless device (e.g., through a transparent screen).

[0076] Fig.10 A method is shown of receiving, by a receiver device, data bits transmitted by a wireless device by passing (particularly reflecting or forwarding) or absorbing an incoming signal (particularly an incoming ambient signal).

[0077] At 1001, the method provides for obtaining a system including a system having a predetermined duration (T c ) of the third mode (q) having a number (L) of code chips.

[0078] If the corresponding chips of a first pattern (p0) associated with a data bit having a value of zero (0) and a second pattern (p1) associated with a data bit having a value of one (1) are equal, the chips of a third pattern (q) are zero. If the corresponding chips of the first pattern are greater than the corresponding chips of the second pattern (p1), the chips of the third pattern (q) have a positive sign. If the corresponding chips of the first pattern (p0) are less than the corresponding chips of the second pattern (p1), the chips of the third pattern (q) have a negative sign.

[0079] At 1002, the method provides for decoding a received pattern (r) representing a data bit based on the third pattern (q).

[0080] In summary, at least the following examples are as described above:

[0081] Example 1. A method of transmitting data bits by a wireless device by passing, in particular reflecting or forwarding, or absorbing an incoming signal, in particular an incoming ambient signal, the method comprising:

[0082] For a data bit having a value of zero (0), obtaining (901) a first pattern (p_0), in particular from a codebook, the first pattern comprising a number (L) of chips having a predetermined duration (T c )

[0083] For a data bit having a value of one (1), obtaining (902) a second pattern (p1), in particular from the codebook, the second pattern (p1) comprising a number (L) of chips having the predetermined duration (T c ) and

[0084] During each chip, passing or absorbing (903) the incoming signal according to the first pattern (p0) or the second pattern (p1),

[0085] wherein the first pattern (p0) and the second pattern (p1) are selected to have an equal number (M < L) of chips during which the incoming signal is absorbed.

[0086] Example 2. The method according to Example 1,

[0087] wherein the first pattern (p0) and the second pattern (p1) are different.

[0088] Example 3. The method according to Example 1 or 2,

[0089] wherein the number (M < L) of chips during which the incoming signal is absorbed is less than six eighths (6 / 8), in particular less than five eighths (5 / 8), and more particularly less than four eighths (4 / 8) of the number (L) of chips of the first pattern (p0).

[0090] Example 4. The method according to any one of Examples 1 to 3,

[0091] wherein the number of chips (M < L) during absorption of the incoming signal is greater than two-eighths (2 / 8), in particular greater than three-eighths (3 / 8), and more particularly greater than four-eighths (4 / 8) of the number of chips (L) of the first mode (p0).

[0092] Example 5. The method according to any one of Examples 1 to 4,

[0093] wherein the number of chips (N < L) that are different between the first mode (p0) and the second mode (p1) is greater than three-eighths (3 / 8), in particular greater than five-eighths, and more particularly greater than seven-eighths (7 / 8) of the number of chips (L) of the first mode (p0).

[0094] Example 6. The method according to any one of Examples 1 to 5,

[0095] wherein the predetermined duration (T c ) is longer than 10 ns, in particular longer than 30 ns, in particular longer than 100 ns, in particular longer than 300 ns, in particular longer than 1000 ns.

[0096] Example 7. The method according to any one of Examples 1 to 6,

[0097] wherein the predetermined duration (T c ) is longer than the delay spread of the channel according to the standardized Extended Pedestrian A (EPA) channel model.

[0098] Example 8. The method according to any one of Examples 1 to 7,

[0099] wherein the predetermined duration (T c ) is shorter than 200 ms, in particular shorter than 180 ms, in particular shorter than 60 ms, in particular shorter than 24 ms, in particular shorter than 13 ms, in particular shorter than 9 ms, in particular shorter than 6 ms, in particular shorter than 5 ms.

[0100] Example 9. The method according to any one of Examples 1 to 8,

[0101] wherein the predetermined duration (T c ) is shorter than the coherence time of the channel according to the standardized Extended Pedestrian A (EPA) channel model.

[0102] Example 10. The method according to any one of Examples 1 to 9,

[0103] Therein, the number of chips in the first mode (p0) is greater than 400, in particular greater than 1000, in particular greater than 1300, in particular greater than 2000.

[0104] Example 11. A method for receiving, by a receiver device, data bits transmitted by a wireless device by passing, in particular reflecting or forwarding, or absorbing an incoming signal, in particular an incoming ambient signal, the method comprising:

[0105] - obtaining (1001) a third pattern (q), said third pattern (q) comprising a predetermined duration (T c ) number of (L) chips,

[0106] wherein the chip of the third pattern (q) is zero if the corresponding chips of the first pattern (p0) associated with a data bit having a value of zero (0) and the second pattern (p1) associated with a data bit having a value of one (1) are equal,

[0107] wherein the chips of the third mode (q) have a positive sign if the corresponding chips of the first mode (p0) are greater than the corresponding chips of the second mode (p1),

[0108] wherein if the corresponding chip of the first mode (p0) is smaller than the corresponding chip of the second mode (p1), the chip of the third mode (q) has a negative sign,

[0109] - decoding (1002) a received pattern (r) representing said data bits based on said third pattern (q).

[0110] Example 12. The method according to Example 11,

[0111] Therein, decoding (1002) the received pattern (r) based on the third pattern (q) comprises multiplying the third pattern (q) with the received pattern (r) to obtain a fourth pattern (y).

[0112] Example 13. The method according to Example 12,

[0113] Therein, decoding (1002) the received mode (r) comprises summing the chips of the fourth mode (y) to obtain a sum.

[0114] Example 14. The method according to Example 13,

[0115] Therein, decoding (1002) the reception pattern (r) comprises deriving whether the sum is greater than zero or less than zero to obtain a data bit value of a received data bit (d).

[0116] Example 15. A method according to any one of Examples 11 to 14,

[0117] Wherein, obtaining (1001) the third mode (q) includes

[0118] - obtaining said first mode (p0),

[0119] - obtaining said second pattern (p1), and

[0120] - deriving said third pattern (q) from said first pattern (p0) and said second pattern (p1).

[0121] Example 16. A method according to any one of Examples 11 to 15,

[0122] Therein, the method comprises receiving, by the receiver device, another data bit transmitted by another wireless device by passing, in particular reflecting or forwarding, or absorbing an incoming signal, in particular an ambient signal, the method comprising:

[0123] - obtaining a component having the predetermined duration (T c ) of another third mode (q2) of number (L) chips,

[0124] Wherein, if another first pattern (p 2，0 ) and another second pattern (p ) associated with another data bit having a value of one (1) 2，1 ) are equal, then the code chip of the other third mode (q2) is zero,

[0125] If the corresponding code chip of the other first mode (p2, 0) is larger than the corresponding code chip of the second mode (p 2，1 ), then the code chips of the other third mode (q2) have a positive sign,

[0126] Wherein, if the other first mode (p 2，0 ) is smaller than the corresponding code chip of the other second mode (p 2，1 ), then the code chips of the other third mode (q2) have a negative sign,

[0127] - decoding said received pattern (r) representing said data bits based on said further third pattern (q2),

[0128] Wherein, the other first mode (p 2，0 ) and / or the other second mode (p 2，1 ) and the peak-to-valley cross-correlation of the first mode (p0) and / or the second mode (p1) is at least

[0129] Example 17. A wireless device (120) comprising a control circuit, wherein the control circuit is configured to perform a method according to any one of Examples 1 to 10.

[0130] Example 18. A receiver device (130) comprising a control circuit, wherein the control circuit is configured to perform a method according to any one of Examples 11 to 15.

Claims

1. A method for a wireless device to transmit data bits by passing or absorbing an incoming signal, the method comprising: For a data bit having a value of zero (0), obtaining (901) includes having a predetermined duration (T c ) of the first pattern (p0) of number (L) chips, For a data bit having a value of one (1), obtaining (902) includes having the predetermined duration (T c ) of a second mode (p1) of number (L) chips, and During each chip period, passing or absorbing (903) the incoming signal according to the first pattern (p0) or the second pattern (p1), wherein the first pattern (p0) and the second pattern (p1) are selected to have an equal number (M < L) of chip periods during which the incoming signal is absorbed.

2. The method according to claim 1, in, the first pattern (p0) and the second pattern (p1) are different.

3. The method according to claim 1 or 2, in, the number (M < L) of chip periods during which the incoming signal is absorbed is less than six eighths (6 / 8), particularly less than five eighths (5 / 8), and more particularly less than four eighths (4 / 8) of the number (L) of chip periods of the first pattern (p0).

4. The method according to any one of claims 1 to 3, in, the number (M < L) of chip periods during which the incoming signal is absorbed is greater than two eighths (2 / 8), particularly greater than three eighths (3 / 8), and more particularly greater than four eighths (4 / 8) of the number (L) of chip periods of the first pattern (p0).

5. The method according to any one of claims 1 to 4, in, the number (N < L) of chip periods in which the first pattern (p0) and the second pattern (p1) are different is greater than three eighths (3 / 8), particularly greater than five eighths (5 / 8), and more particularly greater than seven eighths (7 / 8) of the number (L) of chip periods of the first pattern (p0).

6. The method according to any one of claims 1 to 5, in, The predetermined duration (T c ) is longer than 10ns, in particular longer than 30ns, in particular longer than 100ns, in particular longer than 300ns, in particular longer than 1000ns.

7. The method according to any one of claims 1 to 6, in, The predetermined duration (T c ) is longer than the delay spread of the channel according to the standardized Extended Pedestrian A (EPA) channel model.

8. The method according to any one of claims 1 to 7, in, The predetermined duration (T c ) is shorter than 200ms, in particular shorter than 180ms, in particular shorter than 60ms, in particular shorter than 24ms, in particular shorter than 13ms, in particular shorter than 9ms, in particular shorter than 6ms, in particular shorter than 5ms.

9. The method according to any one of claims 1 to 8, in, The predetermined duration (T c ) is shorter than the coherence time of the channel according to the standardized extended pedestrian A (EPA) channel model.

10. The method according to any one of claims 1 to 9, in, the number of chip periods of the first pattern (p0) is greater than 400, particularly greater than 1000, particularly greater than 1300, and particularly greater than 2000.

11. A method for a receiver device to receive data bits transmitted by a wireless device by passing or absorbing an incoming signal, the method comprising: - obtaining (1001) a third pattern (q), said third pattern (q) comprising a predetermined duration (T c ) number of (L) chips, wherein if the corresponding chip periods of the first pattern (p0) associated with a data bit having a value of zero (0) and the second pattern (p1) associated with a data bit having a value of one (1) are equal, the chip periods of the third pattern (q) are zero, wherein if the corresponding chip periods of the first pattern (p0) are greater than the corresponding chip periods of the second pattern (p1), the chip periods of the third pattern (q) have a positive sign, wherein if the corresponding chip periods of the first pattern (p0) are less than the corresponding chip periods of the second pattern (p1), the chip periods of the third pattern (q) have a negative sign, - Decoding (1002) a received pattern (r) representing the data bit based on the third pattern (q).

12. The method according to claim 11, in, Decoding (1002) the received pattern (r) based on the third pattern (q) comprises multiplying the third pattern (q) with the received pattern (r) to obtain a fourth pattern (y).

13. The method according to claim 12, in, Decoding (1002) the receiving mode (r) includes The chips of the fourth mode (y) are summed to obtain a sum.

14. The method according to claim 13, in, Decoding (1002) the received pattern (r) comprises deriving whether the sum is greater than zero or less than zero to obtain a data bit value of a received data bit (d).

15. The method according to any one of claims 11 to 14, in, Obtaining (1001) the third mode (q) comprises - obtaining said first mode (p0), - obtaining said second pattern (p1), and - deriving said third pattern (q) from said first pattern (p0) and said second pattern (p1).

16. The method according to any one of claims 11 to 15, in, The method comprises receiving, by the receiver device, another data bit transmitted by another wireless device by passing or absorbing an incoming signal, the method comprising: - obtaining a component having the predetermined duration (T c ) of another third mode (q2) of number (L) chips, Wherein, if another first pattern (p 2,0 ) and another second pattern (p ) associated with another data bit having a value of one (1) 2,1 ) are equal, then the code chip of the other third mode (q2) is zero, Wherein, if the other first mode (p 2,0 ) is greater than the corresponding code chip of the second mode (p 2,1 ), then the code chips of the other third mode (q2) have a positive sign, Wherein, if the other first mode (p 2,0 ) is smaller than the corresponding code chip of the other second mode (p 2,1 ), then the code chips of the other third mode (q2) have a negative sign, - decoding said received pattern (r) representing said data bits based on said further third pattern (q2), Wherein, the other first mode (p 2,0 ) and / or the other second mode (p 2,1 ) and the peak-to-valley cross-correlation of the first mode (p0) and / or the second mode (p1) is at least 17. A wireless device (120) comprising a control circuit, wherein: The control circuit is configured to perform the method according to any one of claims 1 to 10.

18. A receiver device (130) comprising a control circuit, wherein: The control circuit is configured to perform the method according to any one of claims 11 to 15.

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