WO2022218120A1 - 一种信号同步方法以及相关设备 - Google Patents

一种信号同步方法以及相关设备 Download PDF

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Publication number
WO2022218120A1
WO2022218120A1 PCT/CN2022/082651 CN2022082651W WO2022218120A1 WO 2022218120 A1 WO2022218120 A1 WO 2022218120A1 CN 2022082651 W CN2022082651 W CN 2022082651W WO 2022218120 A1 WO2022218120 A1 WO 2022218120A1
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Prior art keywords
frame
frame synchronization
data frames
data
group
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PCT/CN2022/082651
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English (en)
French (fr)
Inventor
陈俊
唐瑜键
曲韦霖
汪孙节
吴毅凌
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华为技术有限公司
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Publication of WO2022218120A1 publication Critical patent/WO2022218120A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2656—Frame synchronisation, e.g. packet synchronisation, time division duplex [TDD] switching point detection or subframe synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes

Definitions

  • the embodiments of the present application relate to the field of communications, and in particular, to a signal synchronization method and related devices.
  • the synchronization technology includes frame synchronization and bit synchronization.
  • the frame synchronization technology means that the receiving end determines the starting position of the data frame according to the frame synchronization code contained in the data frame sent by the transmitting end.
  • a frame synchronization technique in the uplink from the reflector to the receiver, is that the reflector sends a preamble including a frame synchronization code to the receiver, and the frame synchronization code adopts FM0 coding or Miller subcarrier modulation coding, and then using amplitude shift keying (ASK) or binary phase shift keying (BPSK) modulation including the preamble of the frame synchronization code, limiting the code to only It is binary.
  • ASK amplitude shift keying
  • BPSK binary phase shift keying
  • the frame synchronization code adopts binary sequence coding methods such as FM0 coding or Miller subcarrier modulation coding
  • the modulation method adopts ASK or BPSK
  • the autocorrelation characteristics of the modulated frame synchronization waveform are poor.
  • the peak will be disturbed by side lobes, and the starting position of the non-delayed data frame corresponding to the peak is not easy to identify, and it is difficult to determine the starting position of the data frame position, which is not conducive to the successful detection and synchronization of the upstream signal by the receiver at low signal-to-noise ratio.
  • the embodiments of the present application provide a signal synchronization method and related equipment, which can enable the receiver to more accurately synchronize and detect the frame synchronization code, further determine the starting position of the data frame, and improve the receiver's performance under low signal-to-noise ratio. demodulation performance.
  • a backscatter system includes a reflector, an exciter, and a receiver.
  • the reflector generates a baseband signal in the circuit, the baseband signal carries N data frames, and each data frame in the N data frames includes at least one set of frame synchronization codes.
  • the function of the frame synchronization code is to identify the starting position of each data frame in the N data frames carried in the baseband signal. Barker codes are used for each group of frame synchronization codes in at least one group of frame synchronization codes.
  • the reflector Before the reflector is modulated, it needs to receive the RF carrier sent by the exciter.
  • the reflector uses the baseband signal to perform backscatter modulation on the incident carrier signal of the reflector, and realizes the target mode modulation by controlling the load impedance of the reflector antenna to obtain a modulated signal.
  • the target mode modulation includes ASK modulation or BPSK modulation, and the modulated signal carries N data frames, each of the N data frames carried in the modulated signal includes at least one group of frame synchronization codes;
  • the reflector backscatters the modulated signal, so that the receiver determines the starting position of each of the N data frames according to at least one set of frame synchronization codes included in each of the N data frames carried in the modulated signal .
  • the Barker code has good autocorrelation characteristics for the frame synchronization code, so that the receiver can detect the frame synchronization code more accurately, further determine the starting position of the data frame, and improve the performance of the frame synchronization code. Receiver demodulation performance at low signal-to-noise ratio.
  • the embodiments of the present application provide a first implementation manner of the first aspect:
  • the structure of the data frame can be various.
  • each data frame includes only one group of Barker codes as the frame synchronization code
  • one of the ways to set the frame synchronization code is to set each group of frame synchronization codes in each data frame. in the frame header.
  • Barker codes when each data frame only includes one group of Barker codes as frame synchronization codes, a better frame synchronization rate is achieved with less overhead;
  • the sequence whose code is a frame synchronization code can be used as a pilot sequence to solve the phase ambiguity problem generated in the BPSK modulation method.
  • the embodiments of the present application provide a second implementation manner of the first aspect:
  • the structure of the data frame can be various.
  • each data frame only includes one group of Barker codes as the frame synchronization code
  • one way to set the frame synchronization code is that each data frame also includes M subframes, and each data frame also includes M subframes.
  • the framing synchronization code is set in the frame header of the first subframe in the M subframes.
  • the embodiment of the present application provides a third implementation manner of the first aspect:
  • the structure of the data frame can be various.
  • each data frame includes multiple groups of Barker codes as the frame synchronization code
  • one of the ways to set the frame synchronization code is that each data frame also includes M subframes.
  • the frame synchronization code is set in the frame header of each of the M subframes.
  • the embodiment of the present application provides a fourth implementation manner of the first aspect:
  • each data frame includes multiple groups of Barker codes as frame synchronization codes
  • one of the ways to set the frame synchronization codes is that each data frame also includes M subframes, which are not included in each data frame.
  • a frame synchronization code is set in one subframe, but several subframes are selected from M subframes, and the frame synchronization code is located in the frame header of each subframe in the several subframes.
  • the embodiment of the present application provides a fifth implementation manner of the first aspect:
  • the data frame can include not only the frame synchronization code, but also the bit synchronization code equal to the number of the frame synchronization code.
  • the synchronization code includes at least 13 clock signals.
  • the embodiment of the present application provides the sixth implementation manner of the first aspect:
  • the number of bit synchronization codes in the data frame may be different from the frame synchronization codes, and the bit synchronization code is only set in the first subframe in the data frame, and the bit synchronization code is not set in other subframes.
  • a backscatter system includes a reflector, an exciter, and a receiver.
  • the reflector generates a baseband signal in the circuit, the baseband signal carries N data frames, and each data frame in the N data frames includes at least one set of frame synchronization codes.
  • the function of the frame synchronization code is to identify the starting position of each data frame in the N data frames carried in the baseband signal.
  • Each group of frame synchronization codes in the at least one group of frame synchronization codes adopts the target sequence generated by the Barker code after Manchester encoding.
  • the reflector Before the reflector is modulated, it needs to receive the RF carrier sent by the exciter.
  • the reflector uses the baseband signal to perform backscatter modulation on the incident carrier signal of the reflector, and realizes the target mode modulation by controlling the load impedance of the reflector antenna to obtain a modulated signal.
  • the target mode modulation includes ASK modulation or BPSK modulation, and the modulated signal carries N data frames, each of the N data frames carried in the modulated signal includes at least one group of frame synchronization codes;
  • the reflector backscatters the modulated signal, so that the receiver determines the starting position of each of the N data frames according to at least one set of frame synchronization codes included in each of the N data frames carried in the modulated signal .
  • the target sequence obtained by the Barker code after Manchester encoding can ensure that the frame synchronization code signal segment has no DC component, and can avoid the influence of the filtering operation of the demodulation device on the frame synchronization code signal segment. It will cause frame synchronization data loss.
  • the embodiments of the present application provide a first implementation manner of the second aspect:
  • the structure of the data frame can be various.
  • each data frame includes only one group of target sequences obtained by Manchester encoding of Barker codes as the frame synchronization code
  • one of the ways to set the frame synchronization code is to use each group of frames.
  • the synchronization code is set in the frame header of each data frame.
  • Barker codes due to the good autocorrelation characteristics of Barker codes, when each data frame only includes one set of target sequences obtained by Manchester coding of Barker codes as frame synchronization codes, it can achieve better performance with less overhead. At the same time, when the target sequence obtained by Manchester encoding of the Barker code is used as the frame synchronization code, the frame synchronization code is used as the pilot sequence to solve the phase ambiguity problem generated in the BPSK modulation method.
  • the embodiments of the present application provide a second implementation manner of the second aspect:
  • the structure of the data frame can be various.
  • each data frame includes only one group of target sequences obtained by Manchester encoding of the Barker code as the frame synchronization code
  • one of the ways to set the frame synchronization code is to set the frame synchronization code in each data frame.
  • M subframes are also included, and each group of frame synchronization codes is set in the frame header of the first subframe in the M subframes.
  • the embodiment of the present application provides a third implementation manner of the second aspect:
  • the structure of the data frame can be various.
  • each data frame includes multiple groups of target sequences obtained by Manchester coding of the Barker code as the frame synchronization code
  • one of the ways to set the frame synchronization code is that each data frame also M subframes are included, and each group of frame synchronization codes is set in the frame header of each subframe in the M subframes.
  • the embodiment of the present application provides a fourth implementation manner of the second aspect:
  • the structure of the data frame can be various.
  • each data frame includes multiple groups of target sequences obtained by Manchester coding of the Barker code as the frame synchronization code
  • one of the ways to set the frame synchronization code is that each data frame also M subframes are included, a frame synchronization code is not set in each subframe, but several subframes are selected from the M subframes, and the frame synchronization code is located in the frame header of each subframe in the several subframes.
  • the embodiment of the present application provides a fifth implementation manner of the second aspect:
  • the data frame can include not only the frame synchronization code, but also the bit synchronization code.
  • the setting of the bit synchronization code can take many ways, which can be the same as or different from the setting method of the frame synchronization code.
  • Each group of bit synchronization codes includes at least 13 clock signal.
  • the embodiment of the present application provides the sixth implementation manner of the second aspect:
  • the number of bit synchronization codes in the data frame may be different from the frame synchronization codes, and the bit synchronization code is only set in the first subframe in the data frame, and the bit synchronization code is not set in other subframes.
  • a backscatter system includes a reflector, an exciter, and a receiver.
  • the reflector generates a baseband signal in the circuit, the baseband signal carries N data frames, and each data frame in the N data frames includes at least one set of frame synchronization codes.
  • the function of the frame synchronization code is to identify the starting position of each data frame in the N data frames carried in the baseband signal.
  • Each group of frame synchronization codes in at least one group of frame synchronization codes adopts Golay complementary sequences.
  • the reflector Before the reflector is modulated, it needs to receive the RF carrier sent by the exciter.
  • the reflector uses the baseband signal to backscatter the incident carrier signal of the reflector, and realizes quadrature phase shift keying (QPSK) modulation by controlling the load impedance of the reflector antenna to obtain a modulated signal, a modulated signal Including in-phase (In-phase, I) branch modulation signal and quadrature (quadrature, Q) branch modulation signal.
  • QPSK quadrature phase shift keying
  • the reflector backscatters the modulated signal, so that after receiving the modulated signal, the receiver synchronizes according to at least one group of frames included in each of the N data frames carried in the demodulated I-channel signal and the Q-channel signal
  • the code determines the starting position of each of the N data frames.
  • the obtained frame synchronization code has ideal autocorrelation characteristics.
  • the embodiments of the present application provide a first implementation manner of the third aspect:
  • the structure of the data frame can be various.
  • one of the ways to set the frame synchronization code is to set each group of frame synchronization codes in each data frame. in the frame header of the frame.
  • the embodiments of the present application provide a second implementation manner of the third aspect:
  • the structure of the data frame can be various.
  • each data frame only includes one group of Gray complementary sequences as the frame synchronization code
  • one of the ways to set the frame synchronization code is that each data frame also includes M subframes.
  • Each group of frame synchronization codes is set in the frame header of the first subframe in the M subframes.
  • the embodiment of the present application provides a third implementation manner of the third aspect:
  • the structure of the data frame can be various.
  • each data frame includes multiple sets of Gray complementary sequences as the frame synchronization code
  • one way to set the frame synchronization code is that each data frame also includes M subframes.
  • the framing synchronization code is set in the frame header of each of the M subframes.
  • the embodiment of the present application provides a fourth implementation manner of the third aspect:
  • the structure of the data frame can be various.
  • each data frame includes multiple sets of Gray complementary sequences as the frame synchronization code
  • one of the ways to set the frame synchronization code is that each data frame also includes M subframes, which are not included in the frame synchronization code.
  • a frame synchronization code is set in each subframe, but several subframes are selected from the M subframes, and the frame synchronization code is located in the frame header of each subframe in the several subframes.
  • the embodiment of the present application provides a fifth implementation manner of the third aspect:
  • the data frame can include not only the frame synchronization code, but also the bit synchronization code.
  • the setting of the bit synchronization code can take many ways, which can be the same as or different from the setting method of the frame synchronization code.
  • Each group of bit synchronization codes includes at least 13 clock signal.
  • each clock signal in the bit synchronization code adopts a QPSK constellation point.
  • the embodiment of the present application provides the sixth implementation manner of the third aspect:
  • the number of bit synchronization codes in the data frame may be different from the frame synchronization codes, and the bit synchronization code is only set in the first subframe in the data frame, and the bit synchronization code is not set in other subframes.
  • a fourth aspect of the embodiments of the present application provides a reflector, and the reflector has the functions of the reflector in the first aspect, the second aspect and the third aspect.
  • This function can be implemented by hardware or by executing corresponding software by hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • a fifth aspect of the embodiments of the present application provides a reflector, including a processor, a memory, an input and output device, and a bus;
  • the processor, the memory, and the input and output devices are connected to the bus;
  • the processor is configured to execute the method described in any one of the above-mentioned first to third aspects.
  • a sixth aspect of an embodiment of the present application provides a computer storage medium, where a program is stored in the computer-readable storage medium, and when the computer executes the program, the computer performs any one of the aforementioned first to third aspects. method described.
  • a seventh aspect of the embodiments of the present application provides a computer program product.
  • the computer program product When the computer program product is executed on a computer, the computer executes the method described in any one of the foregoing first to second aspects.
  • the reflector acquires a baseband signal, the baseband signal carries N data frames, each data frame in the N data frames includes P groups of frame synchronization codes, and each group of frame synchronization codes
  • the code is Barker code.
  • the frame synchronization code adopts Barker code, which has good autocorrelation characteristics, so that the receiver can detect the frame synchronization code more accurately, and further determine the starting position of the data frame. Demodulation performance at noise ratio.
  • Figure 1 is a schematic diagram of the architecture of a bistatic backscatter communication system
  • Figure 2 is a schematic diagram of the architecture of a monostatic backscatter communication system
  • FIG. 3 is a schematic flowchart of a signal synchronization method in an embodiment of the present application.
  • FIG. 4 is another schematic flowchart of a signal synchronization method in an embodiment of the present application.
  • FIG. 5 is a schematic diagram of an application scenario of Manchester encoding in an embodiment of the present application.
  • FIG. 6 is another schematic flowchart of a signal synchronization method in an embodiment of the present application.
  • FIG. 7 is a schematic diagram of an application scenario of a QPSK constellation point in an embodiment of the present application.
  • FIG. 8 is a schematic diagram of the autocorrelation characteristic of a 10-bit Gray complementary sequence in an embodiment of the present application.
  • FIG. 9 is a schematic structural diagram of a data frame in an embodiment of the present application.
  • FIG. 10 is another schematic structural diagram of a data frame in an embodiment of the present application.
  • FIG. 11 is another schematic structural diagram of a data frame in an embodiment of the present application.
  • FIG. 12 is another schematic structural diagram of a data frame in an embodiment of the present application.
  • FIG. 13 is a schematic structural diagram of a reflector in an embodiment of the application.
  • FIG. 14 is another schematic structural diagram of the reflector in the embodiment of the present application.
  • Embodiments of the present application provide a signal synchronization method and related equipment, which are used to enable the receiver to more accurately detect the frame synchronization code, further determine the starting position of the data frame, and improve the receiver's resolution under low signal-to-noise ratio. adjust performance.
  • Backscatter communication system means that the information transmitting device adjusts the matching between its receiving antenna and the antenna load impedance according to the transmitted information, so as to reflect the incident radio frequency signal to varying degrees, and the information receiving device demodulates by detecting the reflected signal.
  • the backscattering device/reflector itself does not generate RF signals, so there is no need to use RF oscillators (oscillators), power amplifiers (power amplifiers) and other devices, so the power consumption of the device can be greatly reduced.
  • Backscatter communication systems have a wide range of applications in today's rapidly developing society. As early as World War II, backscatter communication systems were used in radar systems to distinguish friendly aircraft from enemy aircraft. In daily travel, the electronic toll collection (ETC) set at the highway intersection is another major application of the backscatter communication system.
  • ETC electronic toll collection
  • the modulation method in the backscatter communication system generally adopts amplitude shift keying (ASK) or binary phase shift keying (BPSK), and the frame synchronization code adopts bi-phase space code (bi-phase code). space coding, FM0) or Miller code (Miller code) for signal transmission and synchronization.
  • ASK amplitude shift keying
  • BPSK binary phase shift keying
  • frame synchronization code adopts bi-phase space code (bi-phase code). space coding, FM0) or Miller code (Miller code) for signal transmission and synchronization.
  • the backscatter communication system Compared with large-scale communication systems such as the public land mobile network (PLMN), the backscatter communication system has a simple structure, extremely low cost of terminal equipment and no high-precision clock reference source, and the quality of the transmitted signal is poor.
  • the frame synchronization code is encoded by FM0 or Miller
  • the autocorrelation characteristics are poor, and the sidelobe of the autocorrelation waveform is smaller than the peak value, which will affect the recognition of the peak value of the autocorrelation waveform by the receiving device, resulting in the peak value of the autocorrelation waveform.
  • the recognition accuracy is poor, which is not conducive to the synchronization and detection of the signal by the receiver under low signal-to-noise ratio.
  • a new signal synchronization technique is urgently needed to improve the accuracy of signal synchronization and detection in backscatter communication systems.
  • FIG. 1 The embodiments of the present application can be applied to a bi-static backscatter communication system as shown in FIG. 1 :
  • the bistatic backscatter communication system includes an exciter 101 , a reflector 102 and a receiver 103 .
  • the transmission link from the exciter 101 to the reflector 102 is the downlink, and the transmission link from the reflector 102 to the receiver 103 is the uplink.
  • the exciter 101 is used to send an excitation signal to the reflector 102 to provide the reflector with a radio frequency carrier signal and energy.
  • the reflector 102 is configured to perform a corresponding operation according to the signaling in the excitation signal after receiving the excitation signal sent by the exciter 101 , modulate the signal and send it to the receiver 103 .
  • the reflector 102 changes the load of the antenna based on the information bits to be sent, so that the information bits can be modulated onto the incident carrier wave, so as to realize the wireless transmission of uplink data.
  • the receiver 103 is used to demodulate the signal sent by the reflector 102 .
  • the reader/writer 201 is a device that integrates the transceiver 101 and the receiver 103 in the transceiver separation architecture of the backscatter communication system shown in FIG. 1 .
  • the functions of the reader/writer 201 include all the functions of the exciter 101 and the receiver 103.
  • the reader/writer 201 sends an excitation signal to the tag 202 to provide the tag 202 with power.
  • the tag 202 is composed of an antenna and a chip. Each tag has a unique electronic code and is attached to the object to identify the target object, commonly known as an electronic tag or a smart tag.
  • the tag 202 includes all the functions of the reflector 102 .
  • the reflector obtains the baseband signal carrying the frame synchronization code and the bit synchronization code, modulates the radio frequency carrier sent by the exciter by using the baseband signal, and obtains the modulated signal carrying the frame synchronization code and the bit synchronization code, and reverses the signal. Backscattering the modulated signal enables the receiver to synchronize, detect and demodulate the modulated signal.
  • the baseband signal may carry different frame synchronization codes and bit synchronization codes and target different
  • the frame synchronization code and the bit synchronization code use different modulation methods, which are described below:
  • the frame synchronization code carried in the baseband signal is the Barker code and the bit synchronization code is K clock signals
  • ASK or BPSK modulation is used to obtain a modulated signal carrying the Barker code as the frame synchronization code:
  • the reflector uses the Barker code as the frame synchronization code, and at least 13 clock signals as the bit synchronization code, and encapsulates the bit synchronization code, the frame synchronization code, the target data and the check code in a data frame.
  • the modulated signal is obtained after ASK modulation or BPSK modulation is used, and the modulated signal is backscattered, so that the receiver can synchronize, detect and demodulate the modulated signal.
  • the reflector acquires target data.
  • the reflector generates the target data on its own circuit that needs to be transmitted wirelessly.
  • target data may be encoded by FM0, and may also be encoded by other forms, such as Miller encoding, or Manchester encoding, which is not specifically limited here.
  • the reflector obtains a bit synchronization code, where the bit synchronization code includes K clock signals, and K is greater than or equal to 13.
  • the reflector acquires the bit synchronization code, the bit synchronization code includes at least 13 clock signals, and the frequency of the bit synchronization code is used by the receiver to lock the signal frequency and demodulate the received signal according to the signal frequency.
  • the reflector obtains a frame synchronization code, and the frame synchronization code is a Barker code.
  • the reflector obtains the frame synchronization code, which is used to identify the starting position of a data frame.
  • the frame synchronization code adopts Barker code. Barker codes have good autocorrelation properties and are easy to synchronize in a low signal-to-noise ratio environment. Barker codes can be 2-bit, 3-bit, 4-bit, 5-bit, 7-bit, 11-bit and 13-bit Barker codes, the longer the better. Table 1 below shows the 11-bit Barker code sequence:
  • the reflector obtains the check code.
  • the reflector obtains a check code for the receiver to judge whether the demodulated data has errors, and the check code generally adopts a cyclic redundancy check (CRC).
  • CRC cyclic redundancy check
  • the number of bits of the check code can be selected by yourself, and CRC-6 or CRC-16 can be used.
  • the reflector encapsulates the bit synchronization code, the frame synchronization code, the target data and the check code in a data frame.
  • the reflector After the reflector generates the bit synchronization code, frame synchronization code, target data and check code in its own circuit, it can encapsulate the bit synchronization code, frame synchronization code, target data and check code into a data frame that can be transmitted.
  • the reflector acquires a baseband signal, where the baseband signal carries N data frames.
  • the N data frames to be sent are used as baseband signals.
  • the reflector receives the radio frequency carrier sent by the exciter.
  • the reflector itself does not generate an RF carrier signal, and the reflector receives the RF carrier signal sent by the exciter.
  • step 307 when the reflector itself has a power supply, the baseband signal can be generated independently, that is, after step 306 in step 307, when the reflector has no power supply, the baseband signal needs to be generated with the help of the radio frequency carrier sent by the exciter, that is, step 307 is in Before step 306, step 307 may be after step 306, or may be after step 305 and before step 306, which is not specifically limited here.
  • the reflector uses the baseband signal to perform ASK modulation or BPSK modulation on the radio frequency carrier to obtain a modulated signal.
  • the baseband signal is used to backscatter the incident carrier signal of the reflector, and ASK modulation or BPSK modulation is realized by controlling the load impedance of the reflector antenna to obtain a modulated signal, which carries N data frames.
  • the reflector backscatters the modulated signal.
  • the reflector After the reflector completes the modulation to obtain the modulated signal, it will backscatter the modulated signal, so that the receiver can synchronize, detect and demodulate the modulated signal according to the bit synchronization code and frame synchronization code in the modulated signal.
  • the frame synchronization code adopts Barker code
  • the bit synchronization code adopts at least 13 clock signals. More accurately determine the starting position of each data frame; the use of bit synchronization code includes at least 13 clock signals, which can last longer, making it easier for the receiver to receive the clock signal in the event of delay or packet loss, determine The frequency of the clock signal is thus demodulated.
  • the frame synchronization code carried in the baseband signal is the target sequence obtained by the Manchester encoding of the Barker code, and the bit synchronization code is K clock signals
  • ASK or BPSK modulation is used to obtain the target sequence that carries the target sequence as the frame synchronization code.
  • the reflector uses the target sequence obtained after the Barker code is Manchester encoded as the frame synchronization code, and at least 13 clock signals are used as the bit synchronization code.
  • the reflector acquires target data.
  • the reflector acquires a bit synchronization code, where the bit synchronization code includes K clock signals, and K is greater than or equal to 13.
  • Steps 401 to 402 in this embodiment are similar to steps 301 to 302 in the embodiment shown in FIG. 3 , and details are not repeated here.
  • the reflector acquires a frame synchronization code, where the frame synchronization code is a target sequence obtained by Manchester encoding of the Barker code.
  • the target sequence obtained by the Manchester encoding of the Barker code is used as the frame synchronization code.
  • the Barker code is preferably a 13-bit Barker code, and the 13-bit Barker code is shown in Table 2 below:
  • the reflector obtains the check code.
  • the reflector encapsulates the bit synchronization code, the frame synchronization code, the target data and the check code in a data frame.
  • the reflector acquires a baseband signal, where the baseband signal carries N data frames.
  • the reflector receives the radio frequency carrier sent by the exciter.
  • the reflector uses the baseband signal to perform ASK modulation or BPSK modulation on the radio frequency carrier to obtain a modulated signal.
  • the reflector backscatters the modulated signal.
  • Steps 404 to 409 in this embodiment are similar to steps 304 to 309 in the embodiment shown in FIG. 3 , and details are not repeated here.
  • the target sequence obtained by the Barker code through Manchester encoding can be used as the frame synchronization code to ensure that the frame synchronization code signal segment has no DC component, which can avoid the demodulation equipment.
  • the reflector uses the Gray complementary sequence as the frame synchronization code and the QPSK constellation point as the bit synchronization code, and encapsulates the bit synchronization code, frame synchronization code, target data and check code in a data frame. Then, the modulated signal is obtained after QPSK modulation, and the modulated signal is backscattered so that the receiver can synchronize, detect and demodulate the modulated signal.
  • the reflector acquires target data.
  • Step 601 in this embodiment is similar to step 301 in the embodiment shown in FIG. 3 , and details are not repeated here.
  • the reflector obtains a bit synchronization code, where the bit synchronization code is a QPSK constellation point.
  • Each clock signal in the bit synchronization code can be encoded by two constellation points in a diagonal relationship among the four QPSK constellation points.
  • the selection of the constellation points in this embodiment is shown in Figure 7:
  • each clock signal can have 4 bit synchronization code sequences, as shown in Table 4 below:
  • sequence 1 1+j,-1-j sequence 2 -1-j,1+j sequence 3 -1+j, 1-j sequence 4 1-j,-1+j
  • the reflector obtains a frame synchronization code, where the frame synchronization code is a Gray complementary sequence.
  • the reflector obtains the frame synchronization code used to determine the starting position of the data frame, and the frame synchronization code adopts the Gray complementary sequence.
  • a 10-bit Gray complementary sequence is selected, as shown in Table 5 below:
  • Gray's complementary sequence (10bit) 1+j,1+j,-1-j,1+j,-1+j,1+j,-1+j,-1+j,1-j,1-j
  • the reflector obtains the check code.
  • the reflector encapsulates the bit synchronization code, the frame synchronization code, the target data and the check code in a data frame.
  • the reflector acquires a baseband signal, where the baseband signal carries N data frames.
  • the reflector receives the radio frequency carrier sent by the exciter.
  • Steps 604 to 607 in this embodiment are similar to steps 304 to 307 in the embodiment shown in FIG. 3 , and details are not repeated here.
  • the reflector uses the baseband signal to perform QPSK modulation on the radio frequency carrier to obtain a modulated signal.
  • the baseband signal is used to backscatter the incident carrier signal of the reflector, and the QPSK modulation is realized by controlling the load impedance of the reflector antenna to obtain a modulated signal, which carries N data frames.
  • the amplitudes of the autocorrelation value of the I-channel signal and the autocorrelation waveform of the Q-channel signal when the offset is not 0 are opposite to each other. Therefore, after adding the autocorrelation value of the I-channel signal and the Q-channel signal autocorrelation value
  • the sub-bands of the autocorrelation waveform are all 0, which has ideal autocorrelation characteristics.
  • the reflector backscatters the modulated signal.
  • Step 609 in this embodiment is similar to step 309 in the embodiment shown in FIG. 3 , and details are not repeated here.
  • the receiver is demodulated to obtain the I and Q baseband signals, and the autocorrelation value of the I road-based signal and the autocorrelation value of the Q road-based signal are correlated. After adding, the ideal autocorrelation characteristics are obtained.
  • the data frame may or may not include subframes
  • the frame synchronization code and the bit synchronization code may be set in the data frame or subframe
  • the frame synchronization code and the bit synchronization code may be set in a subframe
  • the The frame synchronization code and the bit synchronization code are set in multiple subframes, which are described below:
  • Subframes are not included in the data frame.
  • each data frame does not include subframes, and the frame synchronization code and the bit synchronization code are directly set in the data frame.
  • the frame synchronization code and the bit synchronization code in this embodiment may be 2 bits, 3 bits, 4 bits, 5 bits, 7 bits, 11 bits and 13-bit Barker code and at least 13 clock signals as described in step 302 in the embodiment shown in FIG. 3;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the target sequence and at least 13 clock signals obtained by Manchester encoding the Barker code as described in step 403 in the embodiment shown in FIG. 4 ;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the Golay complementary sequence described in step 603 and the QPSK constellation point described in step 602 in the embodiment shown in FIG. 6 .
  • the frame structure in this embodiment is described below by taking the bit synchronization code as 24 clock signals and the frame synchronization code as an 11-bit Barker code as an example, please refer to FIG. 9 :
  • each data frame does not include subframes
  • the frame header of each data frame includes 24 clock signals and an 11-bit Barker code
  • the frame end includes a check code
  • the data frame includes multiple subframes, and the frame synchronization code and the bit synchronization code are set in the first subframe.
  • each data frame includes N subframes, and each subframe includes data and a check code, wherein the bit synchronization code and the frame synchronization code are set in the frame header of the first subframe, and in the non-first subframe Only set the data and check code, do not set the frame synchronization code and bit synchronization code.
  • the frame synchronization code and the bit synchronization code in this embodiment may be 2 bits, 3 bits, 4 bits, 5 bits, 7 bits, 11 bits and 13-bit Barker code and at least 13 clock signals as described in step 302 in the embodiment shown in FIG. 3;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the target sequence and at least 13 clock signals obtained by Manchester encoding the Barker code as described in step 403 in the embodiment shown in FIG. 4 ;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the Golay complementary sequence described in step 603 and the QPSK constellation point described in step 602 in the embodiment shown in FIG. 6 .
  • the data frame in this embodiment is described below by taking the bit synchronization code as 48 clock signals and the frame synchronization code as a 13-bit Barker code as an example, please refer to FIG. 10 :
  • Each data frame includes N subframes, the frame header of the first subframe includes 48 clock signals and a 13-bit Barker code, and each non-first subframe only includes data and a check code at the end of the frame.
  • the data frame includes multiple subframes, and a frame synchronization code and a bit synchronization code are set in each subframe.
  • each data frame includes N subframes, a bit synchronization code and a frame synchronization code are set in the header of each subframe, a check code is set at the end of each subframe, and the bit synchronization code in the first subframe
  • the included clock signal is more than the clock signal included in the bit synchronization code in the non-first subframe.
  • the frame synchronization code and the bit synchronization code in this embodiment may be 2 bits, 3 bits, 4 bits, 5 bits, 7 bits, 11 bits and 13-bit Barker code and at least 13 clock signals as described in step 302 in the embodiment shown in FIG. 3;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the target sequence and at least 13 clock signals obtained by Manchester encoding the Barker code as described in step 403 in the embodiment shown in FIG. 4 ;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the Golay complementary sequence described in step 603 and the QPSK constellation point described in step 602 in the embodiment shown in FIG. 6 .
  • bit synchronization code in the first subframe is 48 clock signals
  • bit synchronization code in the non-first subframe is 12 clock signals
  • frame synchronization code in each subframe is a 13-bit Barker code.
  • the frame header of subframe 1 includes 48 clock signals and a 13-bit Barker code
  • the frame header of each subframe in subframes 2 to N includes 12 clock signals and a 13-bit Barker code.
  • Each of subframes 1 to N includes data and a check code.
  • setting the frame synchronization code in each subframe is conducive to determining the starting position of the subframe during subframe-level retransmission, and setting the bit synchronization code in each subframe can calibrate the clock according to the change of the bit synchronization code in each subframe. information to improve synchronization accuracy and demodulation performance.
  • the data frame includes multiple subframes, and a frame synchronization code is set in a part of the subframes.
  • each data frame includes N subframes, the bit synchronization code and the frame synchronization code are set in the first subframe, and the frame synchronization code is set in a selected part of the subframes in other subframes.
  • the frame synchronization code and the bit synchronization code in this embodiment may be 2 bits, 3 bits, 4 bits, 5 bits, 7 bits, 11 bits and 13-bit Barker code and at least 13 clock signals as described in step 302 in the embodiment shown in FIG. 3;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the target sequence and at least 13 clock signals obtained by Manchester encoding the Barker code as described in step 403 in the embodiment shown in FIG. 4 ;
  • the frame synchronization code and the bit synchronization code in this embodiment may also be the Golay complementary sequence described in step 603 and the QPSK constellation point described in step 602 in the embodiment shown in FIG. 6 .
  • bit synchronization code in the first subframe is 48 clock signals
  • frame synchronization code in the first subframe is a 13-bit Barker code
  • frame synchronization code in the non-first subframe is a 13-bit Barker code.
  • the frame header of subframe 1 contains 48 clock signals and a 13-bit Barker code. Select the non-first subframe numbered 2 ⁇ K+1 (K is a positive integer) and set the 13-bit Barker code as the frame synchronization code.
  • the reflector in the embodiment of the present application is introduced below.
  • a structure of the reflector in the embodiment of the present application includes an acquisition unit 1301 , an antenna unit 1302 and a modulation unit 1303 .
  • the obtaining unit 1301 is used to obtain a baseband signal, the baseband signal carries N data frames, each data frame in the N data frames includes a P group frame synchronization code, and the P group frame synchronization code is used to identify each data in the N data frames.
  • the starting position of the frame, each group of frame synchronization codes in the P group of frame synchronization codes is Barker code, and P is an integer greater than or equal to 1;
  • the P frame synchronization code is located at the frame header of each data frame.
  • the frame synchronization code of the P group is located in the frame header of the first subframe in the M subframes, and M is an integer greater than 1.
  • each group of frame synchronization codes in the P groups of frame synchronization codes is located at the frame header of each subframe in the M subframes.
  • the P group of frame synchronization codes are located at the frame header of each of the P subframes, and the M subframes include P subframes.
  • each group of the P group bit synchronization code includes K clock signals, and K is greater than or equal to 13.
  • the antenna unit 1302 is used to receive the radio frequency carrier sent by the exciter
  • the antenna unit 1302 is used for backscattering the modulated signal, so that the receiver can determine the starting position of each data frame in the N data frames according to the P frame synchronization codes.
  • the obtaining unit 1301 is further configured to obtain a baseband signal, the baseband signal carries N data frames, each data frame in the N data frames includes a P group frame synchronization code, and the P group frame synchronization code is used to identify each of the N data frames.
  • the starting position of the data frame, each group of frame synchronization codes in the P group of frame synchronization codes is the target sequence, and the target sequence is the bit sequence obtained by Manchester encoding the Barker code, and P is an integer greater than or equal to 1;
  • the P frame synchronization code is located at the frame header of each data frame.
  • the frame synchronization code of the P group is located in the frame header of the first subframe in the M subframes, and M is an integer greater than 1.
  • each group of frame synchronization codes in the P groups of frame synchronization codes is located at the frame header of each subframe in the M subframes.
  • the P group of frame synchronization codes are located at the frame header of each of the P subframes, and the M subframes include P subframes.
  • each group of the P group bit synchronization code includes K clock signals, and K is greater than or equal to 13.
  • the antenna unit 1302 is used to receive the radio frequency carrier sent by the exciter
  • the modulation unit 1303 is further configured to perform target mode modulation on the radio frequency carrier according to the baseband signal to obtain a modulated signal, the target mode modulation includes amplitude shift keying ASK modulation or binary phase shift keying BPSK modulation, and the modulated signal carries N data frames ;
  • the antenna unit 1302 is used for backscattering the modulated signal, so that the receiver can determine the starting position of each data frame in the N data frames according to the P frame synchronization codes.
  • the obtaining unit 1301 is further configured to obtain a baseband signal, the baseband signal carries N data frames, each data frame in the N data frames includes a P group frame synchronization code, and the P group frame synchronization code is used to identify each of the N data frames.
  • the starting position of the data frame, each group of frame synchronization codes in the P group of frame synchronization codes is a Gray complementary sequence, and P is an integer greater than or equal to 1;
  • the P frame synchronization code is located at the frame header of each data frame.
  • the frame synchronization code of the P group is located in the frame header of the first subframe in the M subframes, and M is an integer greater than 1.
  • each group of frame synchronization codes in the P groups of frame synchronization codes is located at the frame header of each subframe in the M subframes.
  • the P group of frame synchronization codes are located at the frame header of each of the P subframes, and the M subframes include P subframes.
  • each group of the P group bit synchronization code includes K clock signals, and K is greater than or equal to 13.
  • the antenna unit 1302 is used to receive the radio frequency carrier sent by the exciter
  • the modulation unit 1303 is further configured to perform quadrature phase shift keying (QPSK) modulation on the radio frequency carrier according to the baseband signal to obtain a modulated signal, and the modulated signal carries N data frames;
  • QPSK quadrature phase shift keying
  • the antenna unit 1302 is used for backscattering the modulated signal, so that the receiver can determine the starting position of each data frame in the N data frames according to the P frame synchronization codes.
  • FIG. 14 is a schematic structural diagram of a reflector provided by an embodiment of the present application.
  • the reflector 1400 may include one or more central processing units (CPUs) 1401 and a memory 1405, and the memory 1405 stores one or more above applications or data.
  • CPUs central processing units
  • memory 1405 stores one or more above applications or data.
  • the memory 1405 may be volatile storage or persistent storage.
  • a program stored in memory 1405 may include one or more modules, each of which may include a series of instructions to operate on the server.
  • the central processing unit 1401 may be arranged to communicate with the memory 1405 to execute a series of instruction operations in the memory 1405 on the reflector 1400.
  • the reflector 1400 may also include one or more power supplies 1402, one or more wired or wireless network interfaces 1403, one or more input and output interfaces 1404, and/or, one or more operating systems, such as Windows ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.
  • one or more operating systems such as Windows ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.
  • the central processing unit 1401 can perform the operations performed by the reflector in the foregoing embodiments shown in FIG. 3 to FIG. 8 , and details are not repeated here.
  • the disclosed system, apparatus and method may be implemented in other manners.
  • the apparatus embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.
  • the above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.
  • the integrated unit if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium.
  • the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.
  • the aforementioned storage medium includes: U disk, removable hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

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Abstract

本申请实施例公开了一种信号同步方法以及相关设备，用于使接收器可以更加准确地检测帧同步码，提高接收器在低信噪比下的解调性能。本申请实施例方法包括：反射器获取基带信号，其中每组帧同步码为巴克码，反射器接收激励器发送的射频载波，根据基带信号对射频载波进行ASK调制或BPSK调制，得到携带以巴克码作为帧同步码的已调信号，所述反射器反向散射已调信号，使接收器根据帧同步码确定每个数据帧的起始位置。

Description

一种信号同步方法以及相关设备
本申请要求于2021年04月13日提交中国专利局、申请号为CN202110396083.0、发明名称为“一种信号同步方法以及相关设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及通信领域，尤其涉及一种信号同步方法以及相关设备。
背景技术
为了使整个通信系统准确、有序、可靠地工作，收发双方必须有一个统一的时间标准，该时间标准依靠定时系统去完成收发双方时间的一致性，即实现了时间上的同步。同步技术包括帧同步和位同步，帧同步技术是指接收端根据发送端发送的包含在数据帧中的帧同步码确定数据帧的起始位置。
在反向散射(backscatter)系统中，在反射器到接收器的上行链路中，一种帧同步技术是反射器向接收器发送包括帧同步码的前导码(preamble)，帧同步码采用FM0编码或Miller副载波调制编码，然后采用幅移键控(amplitude shift keying，ASK)或二进制相移键控(binary phase shift keying，BPSK)的调制包括帧同步码的前导码，限制了码只能是二元，得到数据帧后发送给接收器，接收器根据帧同步码确定数据帧的起始位置。
但是，当帧同步码采用FM0编码或Miller副载波调制编码等二元序列编码方式，调制方式采用ASK或BPSK时，调制后的帧同步波形的自相关特性较差，若数据帧传输发生延时，自相关特性较差的帧同步波形的自相关波形中，峰值处会被旁瓣干扰，峰值处对应的无延时的数据帧的起始位置不易被识别，进而难以确定数据帧的起始位置，不利于接收器在低信噪比下对上行信号进行成功的检测和同步。
发明内容
本申请实施例提供了一种信号同步方法以及相关设备，能够使接收器可以更加准确得同步和检测到帧同步码，进一步确定数据帧的起始位置，提高接收器在低信噪比下的解调性能。
本申请实施例第一方面提供了一种信号同步方法：
反向散射系统包括反射器、激励器和接收器。其中，反射器在电路中产生基带信号，基带信号携带N个数据帧，N个数据帧中每个数据帧包括至少一组帧同步码。帧同步码的作用是标识基带信号中携带的N个数据帧中每个数据帧的起始位置。至少一组帧同步码中每组帧同步码都采用巴克码。
反射器在调制前，需要接收激励器发送的射频载波。
反射器使用基带信号对反射器入射载波信号做反向散射调制，通过控制反射器天线的负载阻抗实现目标方式调制，得到已调信号，目标方式调制包括ASK调制或BPSK调制，已调信号携带N个数据帧，已调信号中携带的N个数据帧中每个数据帧包括至少一组帧同步码；
反射器反向散射已调信号，使接收器根据已调信号中携带的N个数据帧中每个数据帧包括的至少一组帧同步码确定N个数据帧中每个数据帧的起始位置。
可以理解的是，当调制方式采用ASK或BPSK时，帧同步码采用巴克码具有良好的自相关特性，使接收器可以更加准确地检测到帧同步码，进一步确定数据帧的起始位置，提高接收器在低信噪比下的解调性能。
基于第一方面，本申请实施例提供了第一方面的第一种实施方式：
数据帧的结构可以有多种，当每个数据帧中只包括1组巴克码作为帧同步码时，其中一种设置帧同步码的方式是，将每组帧同步码设置在每个数据帧的帧头中。
可以理解的是，由于巴克码具有良好的自相关特性，当每个数据帧仅包括1组巴克码作为帧同步码时，以较小的开销实现了更优的帧同步率；同时，以巴克码为帧同步码的序列可以作为导频序列，解决BPSK调制方式中产生的相位模糊问题。
基于第一方面或第一方面第一种实施方式，本申请实施例提供了第一方面的第二种实施方式：
数据帧的结构可以有多种，当每个数据帧中只包括1组巴克码作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，将每组帧同步码设置在M个子帧中位于首位的首子帧的帧头中。
基于第一方面至第一方面第二种实施方式中任一种，本申请实施例提供了第一方面的第三种实施方式：
数据帧的结构可以有多种，当每个数据帧中包括多组巴克码作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，将每组帧同步码设置在M个子帧中每个子帧的帧头中。
基于第一方面至第一方面第三种实施方式中任一种，本申请实施例提供了第一方面的第四种实施方式：
数据帧的结构可以有多种，当每个数据帧中包括多组巴克码作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，并不在每一个子帧中设置帧同步码，而是在M个子帧中挑选若干个子帧，帧同步码位于若干个子帧中的每个子帧的帧头中。
基于第一方面至第一方面第四种实施方式中任一种，本申请实施例提供了第一方面的第五种实施方式：
数据帧中不仅可以包括帧同步码，还可以包括与帧同步码数量相等的位同步码，位同步码的设置可以采取多种方式，可以与帧同步码的设置方式相同或不同，每组位同步码中包括至少13个时钟信号。
可以理解的是，更长的位同步码可以使接收器更准确地提取并跟踪反射器时钟，对接收器的比特同步锁定时间要求更加宽松。
基于第一方面至第一方面第五种实施方式，本申请实施例提供了第一方面的第六种实施方式：
数据帧中位同步码的数量可以与帧同步码不同，仅在数据帧中的首子帧内设置位同步码，在其他子帧中不设置位同步码。
本申请实施例第二方面提供了一种信号同步方法：
反向散射系统包括反射器、激励器和接收器。其中，反射器在电路中产生基带信号， 基带信号携带N个数据帧，N个数据帧中每个数据帧包括至少一组帧同步码。帧同步码的作用是标识基带信号中携带的N个数据帧中每个数据帧的起始位置。至少一组帧同步码中每组帧同步码都采用由巴克码经过曼彻斯特(manchester)编码后生成的目标序列。
反射器在调制前，需要接收激励器发送的射频载波。
反射器使用基带信号对反射器入射载波信号做反向散射调制，通过控制反射器天线的负载阻抗实现目标方式调制，得到已调信号，目标方式调制包括ASK调制或BPSK调制，已调信号携带N个数据帧，已调信号中携带的N个数据帧中每个数据帧包括至少一组帧同步码；
反射器反向散射已调信号，使接收器根据已调信号中携带的N个数据帧中每个数据帧包括的至少一组帧同步码确定N个数据帧中每个数据帧的起始位置。
可以理解的是，巴克码经过曼彻斯特编码得到的目标序列，作为帧同步码可以保证帧同步码信号段没有直流分量，可以避免解调设备的滤波操作对帧同步码信号段的影响，滤波操作不会造成帧同步数据损失。
基于第二方面，本申请实施例提供了第二方面的第一种实施方式：
数据帧的结构可以有多种，当每个数据帧中只包括1组将巴克码经过曼彻斯特编码得到的目标序列作为帧同步码时，其中一种设置帧同步码的方式是，将每组帧同步码设置在每个数据帧的帧头中。
可以理解的是，由于巴克码具有良好的自相关特性，当每个数据帧仅包括1组将巴克码经过曼彻斯特编码得到的目标序列作为帧同步码时，以较小的开销实现了更优的帧同步率；同时，将巴克码经过曼彻斯特编码得到的目标序列作为帧同步码时，将帧同步码作为导频序列可以解决BPSK调制方式中产生的相位模糊问题。
基于第二方面或第二方面第一种实施方式，本申请实施例提供了第二方面的第二种实施方式：
数据帧的结构可以有多种，当每个数据帧中只包括1组将巴克码经过曼彻斯特编码得到的目标序列作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，将每组帧同步码设置在M个子帧中位于首位的首子帧的帧头中。
基于第二方面至第二方面第二种实施方式中任一种，本申请实施例提供了第二方面的第三种实施方式：
数据帧的结构可以有多种，当每个数据帧中包括多组将巴克码经过曼彻斯特编码得到的目标序列作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，将每组帧同步码设置在M个子帧中每个子帧的帧头中。
可以理解的是，每个子帧中设置帧同步码有利于子帧级重传时确定子帧的起始位置，提高解调的精确度。
基于第二方面至第二方面第三种实施方式中任一种，本申请实施例提供了第二方面的第四种实施方式：
数据帧的结构可以有多种，当每个数据帧中包括多组将巴克码经过曼彻斯特编码得到的目标序列作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子 帧，并不在每一个子帧中设置帧同步码，而是在M个子帧中挑选若干个子帧，帧同步码位于若干个子帧中的每个子帧的帧头中。
基于第二方面至第二方面第四种实施方式中任一种，本申请实施例提供了第二方面的第五种实施方式：
数据帧中不仅可以包括帧同步码，还可以包括位同步码，位同步码的设置可以采取多种方式，可以与帧同步码的设置方式相同或不同，每组位同步码中包括至少13个时钟信号。
可以理解的是，更长的位同步码可以使接收器更准确地提取并跟踪反射器时钟，对接收器的比特同步锁定时间要求更加宽松。
基于第二方面至第二方面第五种实施方式，本申请实施例提供了第二方面的第六种实施方式：
数据帧中位同步码的数量可以与帧同步码不同，仅在数据帧中的首子帧内设置位同步码，在其他子帧中不设置位同步码。
本申请实施例第三方面提供了一种信号同步方法：
反向散射系统包括反射器、激励器和接收器。其中，反射器在电路中产生基带信号，基带信号携带N个数据帧，N个数据帧中每个数据帧包括至少一组帧同步码。帧同步码的作用是标识基带信号中携带的N个数据帧中每个数据帧的起始位置。至少一组帧同步码中每组帧同步码都采用格雷互补序列(Golay complementary sequences)。
反射器在调制前，需要接收激励器发送的射频载波。
反射器使用基带信号对反射器入射载波信号做反向散射调制，通过控制反射器天线的负载阻抗实现正交相移键控(quadrature phase shift keying，QPSK)调制，得到已调信号，已调信号包括同相(In-phase,I)支路调制信号和正交(quadrature，Q)支路调制信号。
反射器反向散射已调信号，使接收器在接收到已调信号后，根据解调的I路信号和Q路信号中携带的N个数据帧中每个数据帧包括的至少一组帧同步码确定N个数据帧中每个数据帧的起始位置。
可以理解的是，使用格雷互补序列作为帧同步码，并进行QPSK调制后，得到的帧同步码具有理想的自相关特性。
基于第三方面，本申请实施例提供了第三方面的第一种实施方式：
数据帧的结构可以有多种，当每个数据帧中只包括1组格雷互补序列作为帧同步码时，其中一种设置帧同步码的方式是，将每组帧同步码设置在每个数据帧的帧头中。
可以理解的是，由于格雷互补序列具有良好的自相关特性，当每个数据帧仅包括1组格雷互补序列作为帧同步码时，以较小的开销实现了更优的帧同步率；同时，以格雷互补序列为帧同步码的序列可以作为导频序列，解决QPSK调制方式中产生的相位模糊问题。
基于第三方面或第三方面第一种实施方式，本申请实施例提供了第三方面的第二种实施方式：
数据帧的结构可以有多种，当每个数据帧中只包括1组格雷互补序列作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，将每组帧同步码设置在M 个子帧中位于首位的首子帧的帧头中。
基于第三方面至第三方面第二种实施方式中任一种，本申请实施例提供了第三方面的第三种实施方式：
数据帧的结构可以有多种，当每个数据帧中包括多组格雷互补序列作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，将每组帧同步码设置在M个子帧中每个子帧的帧头中。
基于第三方面至第三方面第三种实施方式中任一种，本申请实施例提供了第三方面的第四种实施方式：
数据帧的结构可以有多种，当每个数据帧中包括多组格雷互补序列作为帧同步码时，其中一种设置帧同步码的方式是，每个数据帧还包括M个子帧，并不在每一个子帧中设置帧同步码，而是在M个子帧中挑选若干个子帧，帧同步码位于若干个子帧中的每个子帧的帧头中。
基于第三方面至第三方面第四种实施方式中任一种，本申请实施例提供了第三方面的第五种实施方式：
数据帧中不仅可以包括帧同步码，还可以包括位同步码，位同步码的设置可以采取多种方式，可以与帧同步码的设置方式相同或不同，每组位同步码中包括至少13个时钟信号。
当调制方式为QPSK调制，帧同步码为格雷互补序列时，位同步码中每个时钟信号采用QPSK星座点。
可以理解的是，更长的位同步码保证接收器可提取并跟踪反射器时钟，对接收器的比特同步锁定时间要求更加宽松。
基于第三方面至第三方面第五种实施方式，本申请实施例提供了第三方面的第六种实施方式：
数据帧中位同步码的数量可以与帧同步码不同，仅在数据帧中的首子帧内设置位同步码，在其他子帧中不设置位同步码。
本申请实施例第四方面提供了一种反射器，该反射器具有实现上述第一方面、第二方面和第三方面中反射器的功能。该功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。该硬件或软件包括一个或多个与上述功能对应的模块。
本申请实施例第五方面提供了一种反射器，包括处理器、存储器、输入输出设备以及总线；
处理器、存储器、输入输出设备与总线相连；
处理器用于执行上述第一方面至第三方面中任一项所述的方法。
本申请实施例第六方面提供了一种计算机存储介质，该计算机可读存储介质中保存有程序，当所述计算机执行所述程序时，执行前述第一方面至第三方面中任一项所述的方法。
本申请实施例第七方面提供了一种计算机程序产品，当该计算机程序产品在计算机上执行时，计算机执行前述第一方面至第二方面中任一项所述的方法。
从以上技术方案可以看出，本申请实施例具有以下优点：反射器获取基带信号，基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，每组帧同步码为巴克 码，反射器接收激励器发送的射频载波后，根据基带信号对射频载波进行ASK调制或BPSK调制，反射器反向散射已调信号，使接收器根据P组帧同步码确定所述N个数据帧中每个数据帧的起始位置。当调制方式采用ASK或BPSK时，帧同步码采用巴克码具有良好的自相关特性，使接收器可以更加准确地检测到帧同步码，进一步确定数据帧的起始位置，提高接收器在低信噪比下的解调性能。
附图说明
图1为双基地反向散射通信系统架构示意图；
图2为单基地反向散射通信系统架构示意图；
图3为本申请实施例中信号同步方法的一个流程示意图；
图4为本申请实施例中信号同步方法的另一流程示意图；
图5为本申请实施例中曼彻斯特编码的应用场景示意图；
图6为本申请实施例中信号同步方法的另一流程示意图；
图7为本申请实施例中QPSK星座点的应用场景示意图；
图8为本申请实施例中10比特格雷互补序列的自相关特性示意图；
图9为本申请实施例中数据帧的一个结构示意图；
图10为本申请实施例中数据帧的另一结构示意图；
图11为本申请实施例中数据帧的另一结构示意图；
图12为本申请实施例中数据帧的另一结构示意图；
图13为本申请实施例中反射器的一个结构示意图；
图14为本申请实施例中反射器的另一结构示意图。
具体实施方式
本申请实施例提供了一种信号同步方法以及相关设备，用于使接收器可以更加准确地检测到帧同步码，进一步确定数据帧的起始位置，提高接收器在低信噪比下的解调性能。
反向散射(backscatter)通信系统是指信息发送设备根据发送信息调整其接收天线和天线负载阻抗之间的匹配，从而对入射射频信号进行不同程度的反射，而信息接收设备通过检测反射信号解调信息，以达到信息交换目的的一种通信系统。反向散射设备/反射器自身不产生射频信号，因此不需要使用射频振荡器(oscillator)、功率放大器(power amplifier)等器件，因此可以极大降低设备的功耗。反向散射通信系统在当今科技快速发展的社会中有着广泛的应用。早在二战时期，反向散射通信系统就应用在雷达系统中，用于区分己方飞机和敌方飞机。在日常出行中，高速路口处设置的电子不停车收费系统(electronic toll collection，ETC)，是反向散射通信系统的另一大应用。
反向散射通信系统中的调制方式一般采用幅移键控(amplitude shift keying，ASK)或二进制相移键控(binary phase shift keying，BPSK)，帧同步码采用双相间空号编码(bi-phase space coding，FM0)或密勒码(Miller code)进行信号的传输和同步。
相较于公共陆地移动网(public land mobile network，PLMN)等大型通信系统，反向散射通信系统结构简单，终端设备成本极低且没有高精度的时钟参考源，所传输信号的质量较差。帧同步码经过FM0编码或Miller编码后，自相关特性较差，自相关波形的旁瓣 相较于峰值差别较小，会影响接收设备对自相关波形峰值的识别，从而导致自相关波形峰值的识别精度较差，不利于接收器在低信噪比下对信号的同步和检测。急需一种新的信号同步技术提高反向散射通信系统中信号同步和检测的精度。
本申请实施例可以应用于如图1所示的双基地(bi-static)反向散射通信系统：
双基地反向散射通信系统包括激励器101、反射器102和接收器103。激励器101到反射器102的传输链路是下行链路，反射器102到接收器103的传输链路是上行链路。
激励器101用于向反射器102发送激励信号，为反射器提供射频载波信号和能量。
反射器102用于在接收激励器101发送的激励信号后，根据激励信号中的信令执行相应的操作，将信号进行调制后发送给接收器103。反射器102基于要发送的信息比特改变天线的负载，使得其信息比特可以调制到入射的载波上，实现上行数据的无线传输。
接收器103用于解调反射器102发送的信号。
本申请实施例还可以应用于如图2所示的单基地(mono-static)反向散射通信系统：
读写器201是集成了图1所示的反向散射通信系统的收发分离架构中的激励器101和接收器103的收发一体的设备。读写器201的功能包括激励器101和接收器103的全部功能，读写器201向标签202发送激励信号，为标签202提供电力。
标签202由天线及芯片组成，每个标签具有唯一的电子编码，附着在物体上标识目标对象，俗称电子标签或智能标签，标签202包括反射器102的全部功能。
结合上述介绍，下面对本申请实施例中的信号同步方法进行介绍：
本申请实施例中，反射器获取携带帧同步码和位同步码的基带信号，使用基带信号对激励器发出的射频载波调制后，得到携带帧同步码和位同步码的已调信号，并反向散射该已调信号，使接收机对已调信号进行同步、检测和解调。
需要说明的是，本申请实施例中，为了使携带帧同步码和位同步码的已调信号具有良好的同步检测性能，基带信号中可以携带不同的帧同步码和位同步码并针对不同的帧同步码和位同步码采用不同的调制方式，下面分别进行说明：
一、当基带信号中携带的帧同步码为巴克码，位同步码为K个时钟信号时，采用ASK或BPSK调制，得到携带巴克码作为帧同步码的已调信号：
请参阅图3，本实施例中，反射器将巴克码作为帧同步码，至少13个时钟信号作为位同步码，将位同步码、帧同步码、目标数据和校验码封装在一个数据帧中后，采用ASK调制或BPSK调制后得到已调信号，并反向散射该已调信号，使接收器对已调信号进行同步、检测和解调。
301、反射器获取目标数据。
反射器在自身电路上产生需要进行无线传输的目标数据。
需要说明的是，目标数据可以采用FM0编码，也可以采用其他形式的编码，例如Miller编码，还可以采用曼彻斯特编码，具体此处不做限定。
302、反射器获取位同步码，位同步码包括K个时钟信号，K大于等于13。
反射器获取位同步码，位同步码包括至少13个时钟信号，位同步码的频率用于接收器锁定信号频率，并根据信号频率解调接收的信号。
303、反射器获取帧同步码，帧同步码为巴克码。
反射器获取帧同步码，帧同步码用于标识一个数据帧的起始位置。帧同步码采用巴克码。巴克码具有良好的自相关特性，在低信噪比环境下易于同步。巴克码可以采用2比特、3比特、4比特、5比特、7比特、11比特和13比特的巴克码，越长效果越好。下表1所示为11比特的巴克码序列：
表1
Figure PCTCN2022082651-appb-000001
304、反射器获取校验码。
反射器获取用于接收器判断解调的数据是否存在错误的校验码，校验码一般采用循环冗余校验码(cyclic redundancy check，CRC)。校验码的位数可以自行选择，可以采用CRC-6或CRC-16。
305、反射器将位同步码、帧同步码、目标数据和校验码封装在一个数据帧中。
反射器在自身电路生成了位同步码、帧同步码、目标数据和校验码后，可以将位同步码、帧同步码、目标数据和校验码封装成可以进行传输的数据帧。
306、反射器获取基带信号，基带信号携带N个数据帧。
反射器在完成单个数据帧的封装后，将需要发送的N个数据帧作为基带信号。
307、反射器接收激励器发送的射频载波。
反射器自身不生成射频载波信号，反射器会接收激励器发送的射频载波信号。
需要说明的是，当反射器自身有电源时，可以独立产生基带信号，即步骤307在步骤306之后，当反射器没有电源时，需要借助激励器发送的射频载波产生基带信号，即步骤307在步骤306之前，步骤307可以在步骤306之后，也可以在步骤305之后步骤306之前，具体此处不做限定。
308、反射器使用基带信号对射频载波进行ASK调制或BPSK调制，得到已调信号。
使用基带信号对反射器入射载波信号做反向散射调制，通过控制反射器天线的负载阻抗实现ASK调制或BPSK调制，得到已调信号，已调信号携带N个数据帧。
309、反射器反向散射已调信号。
反射器在完成调制得到已调信号后，会将已调信号反向散射出去，使接收器根据已调信号中的位同步码和帧同步码对已调信号进行同步、检测和解调。
可以理解的是，本实施例中，在ASK或BPSK的调制方式下，帧同步码采用巴克码，位同步码采用包括至少13个时钟信号，巴克码的自相关特性较好，使接收器可以更精确地确定每个数据帧的起始位置；位同步码采用包括至少13个时钟信号，可以持续更长的时间，使接收器更易于在发生延迟或丢包的情况下接收时钟信号，确定时钟信号的频率从而进行 解调。
二、当基带信号中携带的帧同步码为巴克码经过曼彻斯特编码后的得到的目标序列，位同步码为K个时钟信号时，采用ASK或BPSK调制，得到携带目标序列作为帧同步码的已调信号：
请参阅图4，本实施例中，反射器将巴克码经过曼彻斯特编码后得到的目标序列作为帧同步码，至少13个时钟信号作为位同步码，将位同步码、帧同步码、目标数据和校验码封装在一个数据帧中后，采用ASK调制或BPSK调制后得到已调信号，将已调信号散射后使接收器对已调信号进行同步、检测和解调。
401、反射器获取目标数据。
402、反射器获取位同步码，位同步码包括K个时钟信号，K大于等于13。
本实施例中步骤401至402与图3所示实施例中步骤301至302类似，具体此处不再赘述。
403、反射器获取帧同步码，帧同步码为巴克码经过曼彻斯特编码得到的目标序列。
本实施例中，将巴克码经过曼彻斯特编码后得到的目标序列作为帧同步码。巴克码优选13比特的巴克码,13比特的巴克码如下表2所示：
表2
Figure PCTCN2022082651-appb-000002
请参阅图5，曼彻斯特编码的原理是将每个码元均用两个不同相位的电平信号表示，也就是一个周期的方波，但比特0和比特1的相位正好相反。
在巴克码中不存在数据0，所以将巴克码中的-1按照数据0的方式编码，得到26位的目标序列作为帧同步码，如下表3所示：
表3
Figure PCTCN2022082651-appb-000003
404、反射器获取校验码。
405、反射器将位同步码、帧同步码、目标数据和校验码封装在一个数据帧中。
406、反射器获取基带信号，基带信号携带N个数据帧。
407、反射器接收激励器发送的射频载波。
408、反射器使用基带信号对射频载波进行ASK调制或BPSK调制，得到已调信号。
409、反射器反向散射已调信号。
本实施例中步骤404至409与图3所示实施例中步骤304至309类似，具体此处不再赘述。
可以理解的是，本实施例中，在ASK或BPSK的调制方式下，巴克码经过曼彻斯特编码得到的目标序列，作为帧同步码可以保证帧同步码信号段没有直流分量，可以避免解调设备的滤波操作对帧同步码信号段的影响，滤波操作不会造成帧同步数据损失；位同步码采用包括至少13个时钟信号，可以持续更长的时间，使接收器更易于在发生延迟或丢包的情况下接收时钟信号，确定时钟信号的频率从而进行解调。
三、当基带信号中携带的帧同步码为格雷互补序列(Golay complementary sequences)，位同步码为QPSK星座点时，采用QPSK调制，得到携带格雷互补序列作为帧同步码的已调信号：
请参阅图6，本实施例中，反射器以格雷互补序列作为帧同步码，QPSK星座点作为位同步码，将位同步码、帧同步码、目标数据和校验码封装在一个数据帧中后，采用QPSK调制后得到已调信号，将已调信号反向散射后使接收器对已调信号进行同步、检测和解调。
601、反射器获取目标数据。
本实施例中步骤601与图3所示实施例中步骤301类似，具体此处不再赘述。
602、反射器获取位同步码，位同步码为QPSK星座点。
位同步码中每个时钟信号可以采用4个QPSK星座点中的呈对角关系的两个星座点进行编码，本实施例中星座点的选择如图7所示：
选择I路信号(横轴)和Q路信号(纵轴)形成坐标系中的第一象限和第三象限中的星座点1+j和-1-j作为位同步码中的每个时钟信号，也可以选择第二象限和第四象限中的星座点-1+j和1-j，每个时钟信号可以有4种位同步码序列，如下表4所示：
表4
序列1 1+j,-1-j
序列2 -1-j,1+j
序列3 -1+j，1-j
序列4 1-j,-1+j
603、反射器获取帧同步码，帧同步码为格雷互补序列。
反射器获取用于确定数据帧起始位置的帧同步码，帧同步码采用格雷互补序列。本实施例中选择10比特的格雷互补序列，如下表5所示：
表5
格雷互补序列(10bit)
1+j,1+j,-1-j,1+j,-1+j,1+j,-1+j,-1+j,1-j,1-j
604、反射器获取校验码。
605、反射器将位同步码、帧同步码、目标数据和校验码封装在一个数据帧中。
606、反射器获取基带信号，基带信号携带N个数据帧。
607、反射器接收激励器发送的射频载波。
本实施例中步骤604至607与图3所示实施例中步骤304至307类似，具体此处不再赘述。
608、反射器使用基带信号对射频载波进行QPSK调制，得到已调信号。
使用基带信号对反射器入射载波信号做反向散射调制，通过控制反射器天线的负载阻抗实现QPSK调制，得到已调信号，已调信号携带N个数据帧。
I路信号和Q路信号中以格雷互补序列作为帧同步码的自相关特性以及I路信号的自相关值和Q路信号的自相关值相加之后的帧同步码的自相关特性如图8所示：
I路信号的自相关值与Q路信号的自相关波形在偏移不为0时的幅度互为相反数，因此将I路信号的自相关值和Q路信号的自相关值相加之后的自相关波形的副辦均为0，具有理想的自相关特性。
609、反射器反向散射已调信号。
本实施例中步骤609与图3所示实施例中步骤309类似，具体此处不再赘述。
可以理解的是，使用格雷互补序列作为帧同步码，并进行QPSK调制后，使接收器解调得到I、Q基带信号，并将I路基信号的自相关值和Q路基信号的自相关值相加后，得到理想的自相关特性。
结合上述图3至图8中对本申请实施例中信号同步方法的介绍，下面对本申请实施例中信号同步方法中如步骤305、步骤405和步骤605中所述的由帧同步码、位同步码、目标数据和校验码所组成的数据帧的结构进行介绍：
本申请实施例中数据帧可以包括或不包括子帧，可以在数据帧或子帧中设置帧同步码和位同步码，可以在一个子帧中设置帧同步码和位同步码，也可以在多个子帧中设置帧同步码和位同步码，下面分别进行介绍：
1.数据帧中不包含子帧。
本实施例中，每个数据帧不包含子帧，帧同步码和位同步码直接设置在数据帧中。
需要说明的是，本实施例中的帧同步码和位同步码可以为如图3所示实施例中步骤303所述的2比特、3比特、4比特、5比特、7比特、11比特和13比特的巴克码和如图3所示实施例中步骤302所述的至少13个时钟信号；
本实施例中的帧同步码和位同步码也可以为如图4所示实施例中步骤403中所述的将巴克码经过曼彻斯特编码得到的目标序列和至少13个时钟信号；
本实施例中的帧同步码和位同步码还可以为如图6所示实施例中步骤603所述的格雷互补序列和步骤602所述的QPSK星座点。
下面以位同步码为24个时钟信号，帧同步码为11比特巴克码为例介绍本实施例中的帧结构，请参阅图9：
本实施例中，每个数据帧不包含子帧，每个数据帧的帧头包含24个时钟信号和11比 特的巴克码，帧尾包含校验码。
2.数据帧中包括多个子帧，在首子帧中设置帧同步码和位同步码。
本实施例中，每个数据帧包括N个子帧，每个子帧中都包括数据和校验码，其中在首子帧的帧头中设置位同步码和帧同步码，在非首子帧中仅设置数据和校验码，不设置帧同步码和位同步码。
需要说明的是，本实施例中的帧同步码和位同步码可以为如图3所示实施例中步骤303所述的2比特、3比特、4比特、5比特、7比特、11比特和13比特的巴克码和如图3所示实施例中步骤302所述的至少13个时钟信号；
本实施例中的帧同步码和位同步码也可以为如图4所示实施例中步骤403中所述的将巴克码经过曼彻斯特编码得到的目标序列和至少13个时钟信号；
本实施例中的帧同步码和位同步码还可以为如图6所示实施例中步骤603所述的格雷互补序列和步骤602所述的QPSK星座点。
下面以位同步码为48个时钟信号，帧同步码为13比特的巴克码为例对本实施例中的数据帧进行介绍，请参阅图10：
每个数据帧包括N个子帧，首子帧的帧头包括48个时钟信号和13比特的巴克码，每个非首子帧中仅包括数据和位于帧尾的校验码。
3.数据帧中包括多个子帧，在每个子帧中设置帧同步码和位同步码。本实施例中，每个数据帧包括N个子帧，在每个子帧头中设置位同步码和帧同步码，在每个子帧的子帧尾设置校验码，首子帧中的位同步码包括的时钟信号多于非首子帧中位同步码所包括的时钟信号。
需要说明的是，本实施例中的帧同步码和位同步码可以为如图3所示实施例中步骤303所述的2比特、3比特、4比特、5比特、7比特、11比特和13比特的巴克码和如图3所示实施例中步骤302所述的至少13个时钟信号；
本实施例中的帧同步码和位同步码也可以为如图4所示实施例中步骤403中所述的将巴克码经过曼彻斯特编码得到的目标序列和至少13个时钟信号；
本实施例中的帧同步码和位同步码还可以为如图6所示实施例中步骤603所述的格雷互补序列和步骤602所述的QPSK星座点。
下面以首子帧中的位同步码为48个时钟信号，非首子帧位同步码为12个时钟信号，每个子帧中的帧同步码都为13比特的巴克码为例对本实施例中数据帧结构进行介绍，请参阅图11：
子帧1的帧头包含48个时钟信号和13比特巴克码，子帧2至子帧N中每个子帧的帧头包含12个时钟信号和13比特巴克码。子帧1至子帧N中每个子帧都包含数据和校验码。
可以理解的是，每个子帧中设置帧同步码有利于子帧级重传时确定子帧的起始位置，每个子帧中设置位同步码可以根据每个子帧中位同步码的变化校准时钟信息，提高同步精度和解调性能。
4.数据帧中包括多个子帧，在其中一部分子帧中设置帧同步码。本实施例中，每个数据帧包括N个子帧，在首子帧中设置位同步码和帧同步码，在其他子帧中选择一部分子帧 中设置帧同步码。
需要说明的是，本实施例中的帧同步码和位同步码可以为如图3所示实施例中步骤303所述的2比特、3比特、4比特、5比特、7比特、11比特和13比特的巴克码和如图3所示实施例中步骤302所述的至少13个时钟信号；
本实施例中的帧同步码和位同步码也可以为如图4所示实施例中步骤403中所述的将巴克码经过曼彻斯特编码得到的目标序列和至少13个时钟信号；
本实施例中的帧同步码和位同步码还可以为如图6所示实施例中步骤603所述的格雷互补序列和步骤602所述的QPSK星座点。
下面以首子帧中位同步码为48个时钟信号，首子帧中帧同步码为13比特巴克码，非首子帧中帧同步码为13比特巴克码为例，对本实施例中数据帧结构进行介绍，请参阅图12：
子帧1的帧头包含48个时钟信号和13比特巴克码，选择编号为2×K+1(K为正整数)的非首子帧中设置13比特巴克码作为帧同步码，得到的数据帧中，在编号为2×K的子帧由与首子帧相同的数据和校验码组成，编号为2×K+1的子帧由帧同步码和与首子帧相同的数据和校验码组成。
结合上述对本申请实施例中信号同步方法的介绍，下面对本申请实施例中的反射器进行介绍。
请参阅图13，本申请实施例中反射器的一个结构包括获取单元1301、天线单元1302和调制单元1303。
获取单元1301，用于获取基带信号，基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，P组帧同步码用于标识N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为巴克码，P为大于等于1的整数；
当P等于1时，P组帧同步码位于每个数据帧的帧头。
当P等于1，N个数据帧中每个数据帧包括M个子帧时，P组帧同步码位于M个子帧中的首子帧的帧头，M为大于1的整数。
当N个数据帧中每个数据帧包括M个子帧，P等于M时，P组帧同步码中每组帧同步码位于M个子帧中每个子帧的帧头。
当N个数据帧中每个数据帧包括M个子帧，P大于1且小于M时，P组帧同步码位于P个子帧中每个子帧的帧头，M个子帧包括P个子帧。
当基带信号携带P组位同步码时，P组位同步码中每组位同步码包括K个时钟信号，K大于等于13。
天线单元1302，用于接收激励器发送的射频载波；
调制单元1303，用于根据基带信号对射频载波进行目标方式调制，得到已调信号，目标方式调制包括幅移键控ASK调制或二进制相移键控BPSK调制，已调信号携带N个数据帧；
天线单元1302，用于反向散射已调信号，使接收器根据P组帧同步码确定N个数据帧中每个数据帧的起始位置。
获取单元1301，还用于获取基带信号，基带信号携带N个数据帧，N个数据帧中每个 数据帧包括P组帧同步码，P组帧同步码用于标识N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为目标序列，目标序列为将巴克码经过曼彻斯特编码后得到的比特序列，P为大于等于1的整数；
当P等于1时，P组帧同步码位于每个数据帧的帧头。
当P等于1，N个数据帧中每个数据帧包括M个子帧时，P组帧同步码位于M个子帧中的首子帧的帧头，M为大于1的整数。
当N个数据帧中每个数据帧包括M个子帧，P等于M时，P组帧同步码中每组帧同步码位于M个子帧中每个子帧的帧头。
当N个数据帧中每个数据帧包括M个子帧，P大于1且小于M时，P组帧同步码位于P个子帧中每个子帧的帧头，M个子帧包括P个子帧。
当基带信号携带P组位同步码时，P组位同步码中每组位同步码包括K个时钟信号，K大于等于13。
天线单元1302，用于接收激励器发送的射频载波；
调制单元1303，还用于根据基带信号对射频载波进行目标方式调制，得到已调信号，目标方式调制包括幅移键控ASK调制或二进制相移键控BPSK调制，已调信号携带N个数据帧；
天线单元1302，用于反向散射已调信号，使接收器根据P组帧同步码确定N个数据帧中每个数据帧的起始位置。
获取单元1301，还用于获取基带信号，基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，P组帧同步码用于标识N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为格雷互补序列，P为大于等于1的整数；
当P等于1时，P组帧同步码位于每个数据帧的帧头。
当P等于1，N个数据帧中每个数据帧包括M个子帧时，P组帧同步码位于M个子帧中的首子帧的帧头，M为大于1的整数。
当N个数据帧中每个数据帧包括M个子帧，P等于M时，P组帧同步码中每组帧同步码位于M个子帧中每个子帧的帧头。
当N个数据帧中每个数据帧包括M个子帧，P大于1且小于M时，P组帧同步码位于P个子帧中每个子帧的帧头，M个子帧包括P个子帧。
当基带信号携带P组位同步码时，P组位同步码中每组位同步码包括K个时钟信号，K大于等于13。
天线单元1302，用于接收激励器发送的射频载波；
调制单元1303，还用于根据基带信号对射频载波进行正交相移键控QPSK调制，得到已调信号，已调信号携带N个数据帧；
天线单元1302，用于反向散射已调信号，使接收器根据P组帧同步码确定N个数据帧中每个数据帧的起始位置。
图14是本申请实施例提供的一种反射器结构示意图，该反射器1400可以包括一个或一个以上中央处理器(central processing units，CPU)1401和存储器1405，该存储器 1405中存储有一个或一个以上的应用程序或数据。
其中，存储器1405可以是易失性存储或持久存储。存储在存储器1405的程序可以包括一个或一个以上模块，每个模块可以包括对服务器中的一系列指令操作。更进一步地，中央处理器1401可以设置为与存储器1405通信，在反射器1400上执行存储器1405中的一系列指令操作。
反射器1400还可以包括一个或一个以上电源1402，一个或一个以上有线或无线网络接口1403，一个或一个以上输入输出接口1404，和/或，一个或一个以上操作系统，例如Windows ServerTM，Mac OS XTM，UnixTM,LinuxTM，FreeBSDTM等。
该中央处理器1401可以执行前述图3至图8所示实施例中反射器所执行的操作，具体此处不再赘述。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统，装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统，装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
所述集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的全部或部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。

Claims (14)

  1. 一种信号同步方法，其特征在于，包括：
    反射器获取基带信号，所述基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，所述P组帧同步码用于标识所述N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为巴克码，所述P为大于等于1的整数；
    所述反射器接收激励器发送的射频载波；
    所述反射器根据所述基带信号对所述射频载波进行目标方式调制，得到已调信号，所述目标方式调制包括幅移键控ASK调制或二进制相移键控BPSK调制，所述已调信号携带所述N个数据帧；
    所述反射器反向散射所述已调信号，使接收器根据所述P组帧同步码确定所述N个数据帧中每个数据帧的起始位置。
  2. 根据权利要求1所述的信号同步方法，其特征在于，所述P等于1，所述P组帧同步码位于所述每个数据帧的帧头。
  3. 根据权利要求1所述的信号同步方法，其特征在于，所述P等于1，所述N个数据帧中每个数据帧包括M个子帧，所述P组帧同步码位于M个子帧中的首子帧的帧头，所述M为大于1的整数。
  4. 根据权利要求1所述的信号同步方法，其特征在于，所述N个数据帧中每个数据帧包括所述M个子帧，所述P等于所述M，P组帧同步码中每组帧同步码位于M个子帧中每个子帧的帧头。
  5. 根据权利要求1所述的信号同步方法，其特征在于，所述N个数据帧中每个数据帧包括所述M个子帧，所述P大于1且小于所述M，所述P组帧同步码位于P个子帧中每个子帧的帧头，所述M个子帧包括所述P个子帧。
  6. 根据权利要求1至5中任一项所述的信号同步方法，其特征在于，所述基带信号携带P组位同步码，P组位同步码中每组位同步码包括K个时钟信号，所述K为大于12的整数。
  7. 根据权利要求1至5中任一项所述的信号同步方法，其特征在于，所述基带信号携带一组位同步码，所述一组位同步码位于所述M个子帧中的首子帧中。
  8. 一种信号同步方法，其特征在于，包括：
    反射器获取基带信号，所述基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，所述P组帧同步码用于标识所述N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为目标序列，所述目标序列为将巴克码经过曼彻斯特编码后得到的比特序列，所述P为大于等于1的整数；
    所述反射器接收激励器发送的射频载波；
    所述反射器根据所述射频载波对所述基带信号进行目标方式调制，得到已调信号，所述目标方式调制包括幅移键控ASK调制或二进制相移键控BPSK调制，所述已调信号携带所述N个数据帧；
    所述反射器反向散射所述已调信号，使接收器根据所述P组帧同步码确定所述N个数 据帧中每个数据帧的起始位置。
  9. 一种信号同步方法，其特征在于，包括：
    反射器获取基带信号，所述基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，所述P组帧同步码用于标识所述N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为格雷互补序列，所述P为大于等于1的整数；
    所述反射器接收激励器发送的射频载波；
    所述反射器根据所述基带信号对所述射频载波进行正交相移键控QPSK调制，得到已调信号，所述已调信号携带所述N个数据帧；
    所述反射器反向散射所述已调信号，使接收器根据所述P组帧同步码确定所述N个数据帧中每个数据帧的起始位置。
  10. 一种反射器，其特征在于，包括：
    获取单元，用于获取基带信号，所述基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，所述P组帧同步码用于标识所述N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为巴克码，所述P为大于等于1的整数；
    天线单元，用于接收激励器发送的射频载波；
    调制单元，用于根据所述基带信号对所述射频载波进行目标方式调制，得到已调信号，所述目标方式调制包括幅移键控ASK调制或二进制相移键控BPSK调制，所述已调信号携带所述N个数据帧；
    所述天线单元，还用于反向散射所述已调信号，使接收器根据所述P组帧同步码确定所述N个数据帧中每个数据帧的起始位置。
  11. 一种反射器，其特征在于，包括：
    获取单元，用于获取基带信号，所述基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，所述P组帧同步码用于标识所述N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为目标序列，所述目标序列为将巴克码经过曼彻斯特编码后得到的比特序列，所述P为大于等于1的整数；
    天线单元，用于接收激励器发送的射频载波；
    调制单元，用于根据所述基带信号对所述射频载波进行目标方式调制，得到已调信号，所述目标方式调制包括幅移键控ASK调制或二进制相移键控BPSK调制，所述已调信号携带所述N个数据帧；
    所述天线单元，还用于反向散射所述已调信号，使接收器根据所述P组帧同步码确定所述N个数据帧中每个数据帧的起始位置。
  12. 一种反射器，其特征在于，包括：
    获取单元，用于获取基带信号，所述基带信号携带N个数据帧，N个数据帧中每个数据帧包括P组帧同步码，所述P组帧同步码用于标识所述N个数据帧中每个数据帧的起始位置，P组帧同步码中每组帧同步码为格雷互补序列，所述P为大于等于1的整数；
    天线单元，用于接收激励器发送的射频载波；
    调制单元，用于根据所述基带信号对所述射频载波进行正交相移键控QPSK调制，得到 已调信号，所述已调信号携带所述N个数据帧；
    所述天线单元，还用于反向散射所述已调信号，使接收器根据所述P组帧同步码确定所述N个数据帧中每个数据帧的起始位置。
  13. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质中保存有程序，当所述计算机执行所述程序时，执行如权利要求1至9中任一项所述的方法。
  14. 一种计算机程序产品，其特征在于，当所述计算机程序产品在计算机上执行时，所述计算机执行如权利要求1至9中任一项所述的方法。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020035505A1 (en) * 2000-09-19 2002-03-21 Ho Wan-Chol Mobile communication method and apparatus using backscattering of carrier
US20060082442A1 (en) * 2004-10-18 2006-04-20 Impinj, Inc., A Delaware Corporation Preambles with relatively unambiguous autocorrelation peak in RFID systems
CN101425121A (zh) * 2007-11-01 2009-05-06 中兴通讯股份有限公司 射频识别系统中的信息传输方法
CN102254208A (zh) * 2010-05-18 2011-11-23 中国电子科技集团公司第五十五研究所 声表面波无源射频识别标签和传感器
CN112118086A (zh) * 2019-06-19 2020-12-22 成都华为技术有限公司 一种同步方法及装置
CN112363152A (zh) * 2020-11-04 2021-02-12 北京邮电大学 一种用于毫米波雷达通信系统的共享波形设计及信号处理方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020035505A1 (en) * 2000-09-19 2002-03-21 Ho Wan-Chol Mobile communication method and apparatus using backscattering of carrier
US20060082442A1 (en) * 2004-10-18 2006-04-20 Impinj, Inc., A Delaware Corporation Preambles with relatively unambiguous autocorrelation peak in RFID systems
CN101425121A (zh) * 2007-11-01 2009-05-06 中兴通讯股份有限公司 射频识别系统中的信息传输方法
CN102254208A (zh) * 2010-05-18 2011-11-23 中国电子科技集团公司第五十五研究所 声表面波无源射频识别标签和传感器
CN112118086A (zh) * 2019-06-19 2020-12-22 成都华为技术有限公司 一种同步方法及装置
CN112363152A (zh) * 2020-11-04 2021-02-12 北京邮电大学 一种用于毫米波雷达通信系统的共享波形设计及信号处理方法

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