WO2021120027A1 - 基于相位非连续r-csk调制的电文信号播发方法及装置 - Google Patents

基于相位非连续r-csk调制的电文信号播发方法及装置 Download PDF

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Publication number
WO2021120027A1
WO2021120027A1 PCT/CN2019/126147 CN2019126147W WO2021120027A1 WO 2021120027 A1 WO2021120027 A1 WO 2021120027A1 CN 2019126147 W CN2019126147 W CN 2019126147W WO 2021120027 A1 WO2021120027 A1 WO 2021120027A1
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phase
message
modulation
signal
extended
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PCT/CN2019/126147
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English (en)
French (fr)
Inventor
王盾
陈耀辉
李申阳
陈思源
李东俊
董启甲
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航天恒星科技有限公司
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Priority to PCT/CN2019/126147 priority Critical patent/WO2021120027A1/zh
Priority to CN201980026986.0A priority patent/CN112020830B/zh
Publication of WO2021120027A1 publication Critical patent/WO2021120027A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/03—Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits

Definitions

  • the invention relates to a method and device for broadcasting an electronic text signal based on phase discontinuous R-CSK modulation, belonging to the technical field of communication and navigation signal design.
  • the rate of broadcast messages is generally less than the reciprocal of the spread spectrum code period.
  • the spreading code period of the GPS L1C/A code in the United States is 1ms, and the rate of navigation messages is 50bps;
  • the spreading code period of the WAAS satellite navigation satellite-based augmentation system is 1ms, and the rate of navigation messages is 500sps. If you want to increase the message broadcast rate, you must shorten the code length of the spreading code, or reverse the polarity multiple times in a code cycle, which will reduce the correlation characteristics of signal reception and tracking, and damage the signal reception performance.
  • R-CSK modulation method a repetitive phase shift code shift keying modulation method
  • CSK/R-CSK modulation generally adopts the phase sequence advance or the phase sequence lag mode, and the modulation information symbols are assigned different PRN (pseudo-random noise) phases one by one, and the modulation information is mapped to the PRN code.
  • PRN pseudo-random noise
  • the CSK/R-CSK modulated signal with this phase configuration is likely to produce larger correlation peak sidelobes at the output of the signal demodulator, which interferes with the CSK/R-CSK demodulation decision and increases CSK /R-CSK demodulation error rate.
  • the technical problem to be solved by the present invention is to provide a method for controlling the broadcast of a message signal based on phase discontinuous R-CSK modulation that can effectively solve the needs of broadcasting multiple types of messages in the application of communication and navigation systems, and has good multipath suppression performance.
  • Device The technical problem to be solved by the present invention is to provide a method for controlling the broadcast of a message signal based on phase discontinuous R-CSK modulation that can effectively solve the needs of broadcasting multiple types of messages in the application of communication and navigation systems, and has good multipath suppression performance.
  • the present invention adopts the following technical solutions:
  • the present invention provides a method for broadcasting an electronic text signal based on phase discontinuous R-CSK modulation, which includes:
  • the basic message is modulated on the in-phase I branch, and the basic message is BPSK-DSSS direct sequence spread spectrum to construct the in-phase I branch baseband signal;
  • the extended message is modulated on the quadrature Q branch, and the extended message is phase-discontinuous R-CSK-DSSS direct sequence spread spectrum to construct the quadrature Q branch baseband signal; that is, when the extended message is modulated, each standby
  • the modulation symbol determines the pseudo-random spreading sequence, and the basic pseudo-random spreading sequence is cyclically shifted to maintain a fixed phase interval between two adjacent symbols to be modulated.
  • the fixed phase interval is at least greater than one
  • the chip phase of the pseudo-random spreading sequence that is, the initial phase (in chip unit) of the pseudo-random spreading sequence corresponding to two adjacent modulation symbols of any value is a fixed value, and the difference is two Above chip
  • phase interval Z and any value in the message to be modulated is expressed as i
  • the in-phase I branch baseband signal is constructed as follows:
  • the basic message spreading code generator According to the basic message spreading code cycle clock and Chip clock provided by the timing generator, the basic message spreading code generator generates the basic message spreading code C B (t), and the bit stream D B ( t) Perform BPSK-DSSS direct sequence spread spectrum modulation, and update the bit stream corresponding to the basic message to C B (t) ⁇ D B (t);
  • press S I (t) A I ⁇ C B (t) ⁇ D B (t) to obtain the in-phase I branch baseband signal S I (t).
  • the quadrature Q branch baseband signal is constructed as follows:
  • the timing generator According to the extended message symbol clock provided by the timing generator, perform 1->K R bit serial/parallel conversion on the corresponding bit stream after the extended message is encoded to obtain a parallel data stream; wherein the parallel data duration of each K R bit is the symbol time The length is equal to N times the cycle time of the extended message spreading code;
  • the phase selection module According to the extended message spreading code cycle clock provided by the timing generator, the phase selection module generates the phase offset corresponding to the parallel data stream according to the preset phase equal interval non-continuous mapping relationship;
  • the extended message spreading code generator According to the extended message code cycle clock, Chip clock, and the phase offset corresponding to the parallel data stream provided by the timing generator, the extended message spreading code generator generates the extended message spreading code, based on the extended message spreading
  • the code is repeated many times, or repeated zero times, that is, it does not repeat the phase and equal interval discontinuous configuration code shift keying modulation to obtain the modulated spreading message spreading code signal And combined with the preset extended message power ratio coefficient A Q , press
  • Obtain the pseudo-random spreading sequence S Q (t), that is, the quadrature Q branch baseband signal S Q (t), where the code phase of the pseudo-random spreading sequence is controlled by the spread message, (A I ) 2 +(A Q ) 2 1.
  • this modulation method is CSK modulation.
  • the extended text symbol clock is an integer multiple of the extended text code cycle clock and is synchronized with the extended text code cycle clock.
  • the present invention also provides an electronic text signal broadcasting device based on phase non-continuous R-CSK modulation, including:
  • the first modulation unit is used to modulate the basic message on the in-phase I branch, perform BPSK-DSSS direct sequence spreading on the basic message, and construct the in-phase I branch baseband signal;
  • the second modulation unit is used to modulate the extended message on the quadrature Q branch, perform phase non-continuous R-CSK-DSSS direct sequence spreading on the extended message, and construct a quadrature Q branch baseband signal; that is, perform the extended message
  • a pseudo-random spreading sequence is determined for each symbol to be modulated, and the basic pseudo-random spreading sequence is cyclically shifted to maintain a fixed phase interval between two symbols to be modulated with adjacent values.
  • the fixed phase interval is at least greater than the chip phase of a pseudo-random spreading sequence, that is, the phase interval between the initial phases (in chip units) of the pseudo-random spreading sequence corresponding to two adjacent modulation symbols of any value is Fixed value, and the difference is more than two chips;
  • the carrier modulation unit is used to perform IQ quadrature modulation on the basic text baseband signal of the in-phase I branch and the extended text baseband signal of the quadrature Q branch to obtain an intermediate frequency carrier signal, and then perform up-conversion processing on the intermediate frequency carrier signal to obtain a radio frequency Carrier signal
  • the sending unit is used to amplify the power of the radio frequency carrier signal to form a dual-rate composite text signal for broadcasting.
  • phase interval Z and any value in the message to be modulated is expressed as i
  • the first modulation unit includes:
  • Coding sub-unit for performing channel coding for substantially messages encoded bit stream obtained after D B (t);
  • the first spread spectrum modulation subunit is used to generate the basic message spreading code C B (t) from the basic message spreading code generator according to the basic message spreading code cycle clock and Chip clock provided by the timing generator.
  • eligible basic message corresponding to a bit stream D B (t) for BPSK-DSSS direct sequence spread spectrum modulation a basic message corresponding to the updated bit stream C B (t) ⁇ D B (t);
  • the second modulation unit includes:
  • the coding subunit is used to perform channel coding for the extended message to obtain the coded bit stream;
  • the serial/parallel conversion subunit is used to perform 1->K R bit serial/parallel conversion on the corresponding bit stream after encoding the extended message according to the extended message symbol clock provided by the timing generator to obtain a parallel data stream; where every K R Bit parallel data duration, that is, the symbol time length is equal to N times the cycle time of the extended message spreading code;
  • the phase offset subunit is used to generate the phase offset corresponding to the parallel data stream according to the extended message spreading code cycle clock provided by the timing generator, and the phase selection module according to the preset phase equal interval non-continuous mapping relationship;
  • the second spread-spectrum modulation subunit is used to generate the extended-text spread-spectrum code according to the extended-text code cycle clock, the Chip clock, and the phase offset corresponding to the parallel data stream provided by the timing generator, based on the extended-text code
  • this modulation method is CSK modulation.
  • the extended text symbol clock is an integer multiple of the extended text code cycle clock and is synchronized with the extended text code cycle clock.
  • the method for broadcasting a text signal based on phase discontinuous R-CSK modulation of the present invention has the following excellent effects:
  • the message signal broadcasting method based on phase non-continuous R-CSK modulation of the present invention adopts IQ two-channel quadrature modulation, wherein the in-phase I branch adopts BPSK binary phase shift keying carrier modulation, and the baseband signal is DSSS direct sequence spread spectrum Basic telegram; BPSK binary phase shift keying carrier modulation is used on the quadrature Q branch.
  • the baseband signal is a pseudo-random code shift keying modulation with equal intervals and non-continuous configuration of phase shifting after multiple repetitions, or repeated zero times, that is, non-repetitive phase shifting.
  • the code phase of the pseudo-random sequence is controlled by the spreading message; under the condition of the same spreading code length or cycle, using CSK modulation method can obtain a higher message broadcast rate than DSSS direct sequence spreading;
  • the invention uses code-shift keying modulation with multiple repeated phase shifts. Compared with the conventional CSK modulation system, the demodulation performance of the receiver can be effectively improved when the effective information rate is the same; it can improve the transmission of CSK modulation information. At the same time, it keeps the signal power density at the receiving end unchanged, and avoids greatly increasing the software and hardware cost and power consumption of demodulating CSK messages at the receiving end; the present invention assigns different PRN phases for modulation information symbols one by one, and the phases are not continuous.
  • the present invention adopts the R-CSK modulation with equal phase interval discontinuous configuration, compared with the conventional phase continuous configuration CSK/R-CSK modulation system, it can effectively suppress the interference of multipath signals with the delay time between the specified phases, and improve the receiver's resolution.
  • Adjusting performance because the present invention puts the basic message and the extended message on the orthogonal IQ branch, different power ratios can be configured for the basic message signal and the extended message signal with different message rates, and the signal broadcast efficiency is improved; due to the IQ branch
  • the channels are orthogonal, and the carrier phase difference is 90 degrees, which can effectively avoid the impact of high-power extended text signals on the basic text signal reception performance; broadcasting BPSK signals on the I branch can provide the Q branch with the synchronization required for CSK demodulation Information can effectively broadcast the basic message; because the basic message signal and the extended message signal have different spreading codes and the carrier is orthogonal, system users who only need to receive the basic message do not need to consider the existence of the extended message, which can simplify the design of the basic message receiver. Reduce the cost of basic text receivers.
  • the method of the invention is suitable for the fields of communication, navigation system design and the like.
  • Fig. 1 is a block diagram of the broadcasting method in the broadcasting method of the electronic text signal based on phase discontinuous R-CSK modulation according to the present invention
  • Figure 2 shows the timing relationship of the components of the I branch baseband signal
  • Figure 3 shows the timing relationship of each component of the Q-branch baseband signal
  • Figure 4 is a constellation diagram of complex baseband signals
  • Figure 5 is a block diagram of a basic text signal receiver
  • Figure 6 is a diagram showing the structure of a coherent receiver for dual-rate text signals
  • Figure 7 is a diagram showing the structure of a dual-rate text signal incoherent receiver
  • Figure 8 is a diagram showing the composition of a comb filter
  • Figure 9 is a block diagram of the principle of multipath interference signal formation
  • Figure 10(a) is a diagram of the phase mapping relationship between conventional CSK/R-CSK modulation information and PRN code (phase order is advanced);
  • Figure 10(b) is a diagram of the phase mapping relationship between conventional CSK/R-CSK modulation information and PRN code (phase sequence lagging);
  • Figure 11 is a block diagram of the analysis of the influence mechanism of multipath signals
  • Figure 12 is an analysis diagram of the influence of conventional CSK/R-CSK modulated multipath signals
  • Figure 13 is a curve diagram of the theoretical bit error rate of conventional CSK/R-CSK modulation information transmission when multipath interference signals are present or not;
  • Fig. 14 is a diagram showing the relationship between phase non-continuous R-CSK modulation information and PRN code phase mapping proposed by the present invention
  • Fig. 15 is a diagram showing the influence analysis of the phase discontinuous CSK/R-CSK modulated multipath signal proposed by the present invention.
  • FIG. 16 is a comparison diagram of the simulation effect of the information transmission error rate of the phase non-continuous R-CSK of the present invention and the conventional R-CSK information error rate in a multipath scenario;
  • Fig. 17 is a block diagram of the principle of the phase discontinuous R-CSK demodulation matched filter circuit proposed by the present invention.
  • FIG. 18 is a schematic diagram of the composition structure of a text signal broadcasting device based on phase discontinuous R-CSK modulation according to an embodiment of the present invention.
  • the method for broadcasting a text signal based on phase non-continuous R-CSK modulation of the present invention applies IQ two-channel orthogonal modulation to realize the broadcasting of a dual-rate composite text signal.
  • the basic message is modulated on the in-phase I branch, and the basic message is BPSK-DSSS direct sequence spread spectrum to construct the in-phase I branch baseband signal;
  • the extended message is modulated on the quadrature Q branch, and the extended message is phase-discontinuous R-CSK-DSSS direct sequence spread spectrum to construct the quadrature Q branch baseband signal; that is, when the extended message is modulated, each standby
  • the modulation symbol determines the pseudo-random spreading sequence, and the basic pseudo-random spreading sequence is cyclically shifted to maintain a fixed phase interval between two adjacent symbols to be modulated, and the fixed phase interval is at least greater than one
  • the chip phase of the pseudo-random spreading sequence that is, the initial phase (chip unit) of the pseudo-random spreading sequence corresponding to two adjacent modulation symbols of any value is a fixed value, and the difference is two chips the above;
  • the basic message spreading code generator According to the basic message spreading code cycle clock and Chip clock provided by the timing generator, the basic message spreading code generator generates the basic message spreading code C B (t), and the bit stream D B ( t) Perform BPSK-DSSS direct sequence spread spectrum modulation, and update the bit stream corresponding to the basic message to C B (t) ⁇ D B (t);
  • the timing relationship of the components of the in-phase I branch baseband signal is given.
  • press S I (t) A I ⁇ C B (t) ⁇ D B (t) to obtain the in-phase I branch baseband signal S I (t).
  • the timing generator According to the extended message symbol clock provided by the timing generator, perform 1->K R bit serial/parallel conversion on the corresponding bit stream after the extended message is encoded to obtain a parallel data stream; wherein the parallel data duration of each K R bit is the symbol time The length is equal to N times the cycle time of the extended message spreading code;
  • the phase selection module According to the extended message spreading code cycle clock (referred to as the extended message code cycle clock in Figure 1) provided by the timing generator, the phase selection module generates the phase corresponding to the parallel data stream according to the preset phase equal interval non-continuous mapping relationship Offset.
  • the period length of the extended message spreading code is L chips
  • the information symbol K R bits and the number of corresponding information symbols are
  • the configured phase interval is Z, where Z is an integer greater than 1.
  • FIG. 3 shows the timing relationship of each component of the quadrature Q branch signal.
  • the extended message symbol clock time length T ES,R is equal to N times the extended message spreading code cycle clock time length T EC , and K R bit is used to represent a symbol .
  • the broadcast rate of extended message information R E K R /T ES,R .
  • the extended message spreading code generator According to the extended message code cycle clock, Chip clock, and the phase offset corresponding to the parallel data stream provided by the timing generator, the extended message spreading code generator generates the extended message spreading code, based on the extended message spreading
  • the code is repeated many times, or repeated zero times, that is, it does not repeat the phase and equal interval discontinuous configuration code shift keying modulation to obtain the modulated spreading message spreading code signal And combined with the preset extended message power ratio coefficient A Q , press Obtain the pseudo-random spreading sequence S Q (t), that is, the quadrature Q branch baseband signal S Q (t), where the code phase of the pseudo-random spreading sequence is controlled by the spreading message.
  • this modulation method is CSK modulation.
  • the phase interval Z is an integer greater than one.
  • the delay time of the multipath interference signal is ⁇ m (chip unit)
  • the code phase of the multipath interference signal is among them The code phase set for the signal transmitter according to the preset phase mapping relationship.
  • the delay time of the multipath interference signal exceeds 1 spreading code chip and is less than Z-1 chip, the code phase of the multipath interference signal will not be the same as any preset code phase, and it will not Any correlation peak sidelobe interference is generated at the receiver CSK/R-CSK signal demodulation output.
  • the CSK/R-CSK modulated signal with the phase interval set to 64 will not be affected by the multipath interference signal with a delay path of 30 to 1890 meters.
  • the equal interval phase configuration can obtain the maximum suppression range of the multipath interference signal delay.
  • the branch with a higher message rate is generally configured with higher signal broadcast power .
  • the two branches use different spreading code sequences.
  • the IQ branch can allocate different transmission powers, so that the basic message and the extended message received by the receiving end have the same receiving performance.
  • the spreading codes and telegrams of the two channels of the broadcast signal IQ are synchronized with each other.
  • j is an imaginary number.
  • the dual-rate composite text signal is handed over to the transmitting antenna for broadcast.
  • the RF transmission signal of the dual-rate composite text signal is expressed as follows:
  • P s represents the total transmitted power of the composite message radio frequency signal
  • f c represents the frequency of the transmitted signal
  • the basic message and the extended message are respectively placed on orthogonal IQ branches, and the broadcast rate of the extended message only needs to be increased by increasing the power of the extended message signal.
  • IQ branches are orthogonal, and the carrier phase difference is 90 degrees, which can effectively avoid the impact of high-power extended text signals on the reception performance of basic text signals;
  • BPSK signals broadcast on the I branch can be Q branches
  • the present invention further designs a dual-rate message signal receiving method, including the basic message receiving method and extensions in the message signal based on phase discontinuous R-CSK modulation.
  • the method of coherent demodulation and reception of telegrams and the method of non-coherent demodulation of extended telegrams; among them, the basic method of telegram reception, as shown in Figure 5, is specifically as follows:
  • the radio frequency carrier signal received by the receiver antenna is processed by the RF Front-End to output a digital intermediate frequency signal; the digital intermediate frequency signal is first mixed with the carrier copied by the carrier loop to output orthogonal IQ two-way baseband signals, and IQ two-way baseband signals Respectively perform correlation operations with the basic message spreading code copied by the basic message spreading code generator to obtain two IQ correlation results; then, the IQ two correlation results are used as the input of the phase discrimination filter module, and the phase discrimination filter module calculates the carrier phase discrimination Error and code phase detection error, and filter the phase detection error.
  • the filtering results are used to adjust the carrier NCO (Carrier NCO) and code NCO (Code NCO) respectively, so that the carrier output by the Carrier NCO is consistent with the received carrier, and
  • the basic message spreading code copied by the basic message spreading code generator under the control of Code NCO is consistent with the received basic message spreading code, ensuring that the carrier and spreading codes in the received signal at the next moment are still completely in the tracking loop Stripping;
  • the correlation result output by the I branch correlator is judged by the basic message judgment module to output basic message data bits.
  • the extended message spreading code cycle clock and chip clock obtained after synchronization are synchronized with the received signal are passed to the extended message spreading code generator and the coherent matched filter module, and the extended message symbol clock and the extended message are transferred to the extended message spreading code generator and the coherent matched filter module.
  • the spreading code cycle clock is passed to the comb filter;
  • the Q branch baseband signal is passed to the comb filter, and the comb filter superimposes N sets of pseudo-random sequence data in the same symbol into 1 set of pseudo-random sequence data;
  • the block diagram of the comb filter is shown in Figure 8.
  • the comb filter delays the input data sequence by N-1 times under the control of the extended message spreading code cycle clock, and each time the delay extends the message spreading code Cycle time T EC seconds, and then superimpose the N-1 delay data with the input data and send it to the data interception module; secondly, the data interception module intercepts the input under the control of the extended message symbol clock and the extended message spreading code cycle clock Data stream, output the data superimposed N times in the same symbol, and the data time length is the extended message spreading code cycle time T EC seconds. The intercepted data is sent to the coherent matched filtering module.
  • the coherent matched filtering module combines the received data block with a time length of T EC and the extended message spreading code generator in the extended message spreading code cycle.
  • Correlation matching calculation is performed on the spreading code of the extended message generated under the control of the clock and the Chip clock, and the correlation result is output to the correlation peak search module to search for the phase of the local spreading code corresponding to the correlation peak, and convert the phase into bit data for output;
  • bit data output by the correlation peak search module is passed through the channel decoding module to obtain the transmitted extended text data.
  • the extended message spreading code cycle clock and Chip clock obtained after synchronization are synchronized with the received signal are passed to the extended message spreading code generator and the non-coherent matched filter module, and the extended message symbol clock and extended
  • the message spreading code cycle clock is passed to the comb filter;
  • the baseband IQ two signals are passed to the comb filter, and the comb filter superimposes N sets of pseudo-random sequence data in the same symbol into 1 set of pseudo-random sequence data;
  • the block diagram of the comb filter is shown in Figure 8.
  • the comb filter delays the input data sequence by N-1 times under the control of the extended message spreading code cycle clock, and each time the delay extends the message spreading code Cycle time T EC seconds, and then superimpose the N-1 delay data with the input data and send it to the data interception module; secondly, the data interception module intercepts the input under the control of the extended message symbol clock and the extended message spreading code cycle clock Data stream, output the data superimposed N times in the same symbol, and the data time length is the extended message spreading code cycle time T EC seconds. The intercepted data is sent to the incoherent matched filtering module.
  • the non-coherent matched filter module under the control of the extended message symbol clock and the extended message spreading code cycle clock, combines the received data block with a time length of T EC and the extended message spreading code generator in the extended message spreading code
  • the extended message spreading code generated under the control of the period clock and the Chip clock performs correlation matching calculation, and the correlation result is output to the correlation peak search module to search for the phase of the local extended message spreading code corresponding to the correlation peak, and convert the phase into bit data for output;
  • bit data output by the correlation peak search module is passed through the channel decoding module to obtain the transmitted extended text data.
  • Figure 9 shows the principle block diagram of the formation of multipath interference signals.
  • the transmitted signal is a multipath signal.
  • the time delay for the multipath signal to reach the receiver is longer than the direct signal, and due to reflection loss and spatial propagation loss, the power of the multipath signal is weaker than the power of the direct signal.
  • Conventional CSK/R-CSK modulation generally adopts the phase sequence advance or the phase sequence lag mode to assign different PRN phases to the modulation information symbols one by one, and map the modulation information to a continuous phase area of the PRN code, as shown in Figure 10(a) And Figure 10(b) takes CSK(6) as an example, and respectively shows the phase mapping relationship diagrams of the phase sequence leading and the phase sequence lagging.
  • the multipath signal with the entire digital chip time delay is likely to cause large correlation peak sidelobes at the output of the CSK/R-CSK signal demodulator, which will interfere with the CSK/R-CSK demodulation decision.
  • Increase CSK/R-CSK demodulation error rate Take the conventional CSK/R-CSK modulation information and PRN code phase mapping relationship diagram (phase order advance) shown in Figure 10(a) as an example.
  • the modulation information is 30 and the multipath time delay is 5
  • the simulation is performed when the power of the multipath signal is attenuated by 3dB compared with the direct signal, and the phase difference with the direct signal carrier is 0 degrees.
  • Figure 11 shows the analysis diagram of the multipath influence mechanism under the above simulated conditions.
  • This multipath signal delay is consistent with the mapping phase of the modulation information 25.
  • Multipath signals with different chip delays have different effects on different modulation information symbols.
  • the conventional CSK/R-CSK modulation information and PRN code phase mapping diagram (phase order advance) shown in Figure 10(a) as an example.
  • CSK(6) modulation when the modulation message is 0, it will not There is a large correlation peak side lobe formed by the multipath signal, so it will not be affected by the multipath signal, as shown in Figure 12(a); when the modulation message is 30, the time delay of the multipath signal is 1 ⁇ At 30 chips, large correlation peak side lobes formed by the multipath signal will appear, so it will be affected by the multipath signal with a time delay of 1 to 30 chips, as shown in Figure 12(b) ;
  • the modulation message is 63
  • the time delay of the multipath signal is 1 to 63 chips, there will be larger correlation peak sidelobes formed by the multipath signal, so the time delay will be 1 to 63.
  • the influence of the multipath signal of the chip is shown in Figure 12(c); it can also be seen from Figure 12 that the conventional CSK(6) modulated signal will be affected by the multipath signal with a time delay of 1 to 63 chips.
  • the time delay of the multipath signal is greater than 63 chips, since there is no mapping phase of the modulation information within this delay range, there will be no correlation value interference caused by the multipath signal, so it will not be affected by the multipath signal. influences.
  • K is the number of bits per symbol
  • the base M 2 K.
  • Fig. 14 shows a diagram of the phase mapping relationship between one of the phase discontinuous R-CSK modulation information and the PRN code proposed by the present invention.
  • the modulation information symbol is 30, the multipath time delay is 1 to 256 chips, the power of the multipath signal is attenuated by 3dB compared with the direct signal, and the direct signal carrier
  • the simulation is performed when the phase difference is 0 degrees.
  • the influence analysis of the phase discontinuous CSK/R-CSK modulation multipath signal proposed by the present invention is shown in FIG. 15.
  • the multipath delay time is ⁇ 1 chip and ⁇ 63 chips, since there is no mapping phase of the modulation information within this delay range, the correlation value caused by the multipath signal will not be generated. Therefore, it will not be affected by multipath signals in this range.
  • the spreading code chip time is 1 microsecond, this delay time corresponds to the range of 30 to 1890 meters.
  • the phase discontinuous CSK/R-CSK modulation of the present invention can effectively suppress the multipath signal.
  • the influence of path interference signal is a signal that causes the transmission of the multipath signal.
  • the phase discontinuous R-CSK modulation proposed by the present invention can be more intuitively illustrated than the conventional CSK/R-CSK modulation in suppressing multipath interference.
  • the comparison diagram of the simulation effect of the information transmission error rate of the phase non-continuous R-CSK of the present invention and the conventional R-CSK information error rate is shown in FIG. It can be seen that in the presence of 1-chip multipath interference, the information transmission error rate of the phase discontinuous R-CSK of the present invention is basically consistent with the theoretical curve, which is significantly better than conventional R-CSK modulation.
  • FIG. 17 shows a functional block diagram of a demodulation matched filter circuit for phase non-continuous R-CSK modulation proposed by the present invention.
  • the present invention proposes a phase non-continuous R-CSK modulation. CSK modulation hardly increases the cost of signal demodulation operation.
  • FIG. 18 is a schematic diagram of the composition structure of a text signal broadcasting device based on phase discontinuous R-CSK modulation according to an embodiment of the present invention.
  • a text signal broadcasting device based on phase discontinuous R-CSK modulation according to an embodiment of the present invention includes:
  • the first modulation unit 180 is configured to modulate the basic message on the in-phase I branch, perform BPSK-DSSS direct sequence spreading on the basic message, and construct an in-phase I branch baseband signal;
  • the second modulation unit 181 is configured to modulate the extended message on the quadrature Q branch, perform phase non-continuous R-CSK-DSSS direct sequence spreading on the extended message, and construct a quadrature Q branch baseband signal; that is, the extended message
  • a pseudo-random spreading sequence is determined for each symbol to be modulated, and the basic pseudo-random spreading sequence is cyclically shifted to maintain a fixed phase interval between two symbols to be modulated with adjacent values.
  • the fixed phase interval is at least greater than the chip phase of a pseudo-random spreading sequence, that is, the initial phase (chip unit) of the pseudo-random spreading sequence corresponding to two adjacent modulation symbols of any value is fixed. Value, and the difference is more than two chips;
  • the carrier modulation unit 182 is used to perform IQ quadrature modulation on the basic message baseband signal of the in-phase I branch and the extended message baseband signal of the quadrature Q branch to obtain an intermediate frequency carrier signal, and then perform up-conversion processing on the intermediate frequency carrier signal to obtain Radio frequency carrier signal;
  • the sending unit 183 is used to amplify the power of the radio frequency carrier signal to form a dual-rate composite text signal for broadcasting.
  • phase interval Z and any value in the message to be modulated is expressed as i
  • the first modulation unit 180 includes:
  • Coding sub-unit for performing channel coding for substantially messages encoded bit stream obtained after D B (t);
  • the first spread spectrum modulation subunit is used to generate the basic message spreading code C B (t) from the basic message spreading code generator according to the basic message spreading code cycle clock and Chip clock provided by the timing generator.
  • eligible basic message corresponding to a bit stream D B (t) for BPSK-DSSS direct sequence spread spectrum modulation a basic message corresponding to the updated bit stream C B (t) ⁇ D B (t);
  • the second modulation unit 181 includes:
  • the coding subunit is used to perform channel coding for the extended message to obtain the coded bit stream;
  • the serial/parallel conversion subunit is used to perform 1->K R bit serial/parallel conversion on the corresponding bit stream after encoding the extended message according to the extended message symbol clock provided by the timing generator to obtain a parallel data stream; where every K R Bit parallel data duration, that is, the symbol time length is equal to N times the cycle time of the extended message spreading code;
  • the phase offset subunit is used to generate the phase offset corresponding to the parallel data stream according to the extended message spreading code cycle clock provided by the timing generator, and the phase selection module according to the preset phase equal interval non-continuous mapping relationship;
  • the second spread-spectrum modulation subunit is used to generate the extended-text spread-spectrum code according to the extended-text code cycle clock, the Chip clock, and the phase offset corresponding to the parallel data stream provided by the timing generator, based on the extended-text code
  • the extended text symbol clock is an integer multiple of the extended text code cycle clock and is synchronized with the extended text code cycle clock.
  • this modulation method is CSK modulation.
  • the method for broadcasting a text signal based on phase discontinuous R-CSK modulation of the present invention has the following excellent effects:
  • the message signal broadcasting method based on phase non-continuous R-CSK modulation of the present invention adopts IQ two-channel quadrature modulation, wherein the in-phase I branch adopts BPSK binary phase shift keying carrier modulation, and the baseband signal is DSSS direct sequence spread spectrum Basic telegram; BPSK binary phase shift keying carrier modulation is used on the quadrature Q branch.
  • the baseband signal is a pseudo-random code shift keying modulation with equal intervals and non-continuous configuration of phase shifting after multiple repetitions, or repeated zero times, that is, non-repetitive phase shifting.
  • the code phase of the pseudo-random sequence is controlled by the spreading message; under the condition of the same spreading code length or cycle, using CSK modulation method can obtain a higher message broadcast rate than DSSS direct sequence spreading;
  • the invention uses code-shift keying modulation with multiple repeated phase shifts. Compared with the conventional CSK modulation system, the demodulation performance of the receiver can be effectively improved when the effective information rate is the same; it can improve the transmission of CSK modulation information. At the same time, it keeps the signal power density at the receiving end unchanged, and avoids greatly increasing the software and hardware cost and power consumption of demodulating CSK messages at the receiving end; the present invention assigns different PRN phases for modulation information symbols one by one, and the phases are not continuous.
  • the present invention adopts the phase equal interval discontinuous configuration R -CSK modulation, compared with the conventional phase continuous configuration CSK/R-CSK modulation system, it can effectively suppress the multipath signal interference with the delay time between the specified phases, and improve the demodulation performance of the receiver;
  • the messages are placed on orthogonal IQ branches, and different power ratios can be configured for the basic message signals and extended message signals with different message rates, which improves the signal broadcast efficiency; because the IQ branches are orthogonal, the carrier phase difference is 90 degrees.
  • broadcasting BPSK signals on the I branch can not only provide the synchronization information required for CSK demodulation for the Q branch, but also effectively broadcast the basic text;
  • the spreading codes of the telegram signal and the extended telegram signal are different and the carrier is orthogonal. System users who only need to receive the basic telegram do not need to consider the existence of the extended telegram, which can simplify the design of the basic telegram receiver and reduce the cost of the basic telegram receiver.
  • the method of the invention is suitable for the fields of communication, navigation system design and the like.

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Abstract

本发明公开了一种基于相位非连续R-CSK调制的电文信号播发方法及装置，所述方法包括：将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位(以码片为单位)间的相位间隔为固定值，且相差两个码片以上；对同相I支路的基本电文基带信号与正交Q支路的扩展电文基带信号进行IQ正交调制，构成双速率复合电文信号并播发。

Description

基于相位非连续R-CSK调制的电文信号播发方法及装置 技术领域
本发明涉及的基于相位非连续R-CSK调制的电文信号播发方法及装置，属于通信、导航信号设计技术领域。
背景技术
在当代通信、导航系统设计中，根据应用需求的不同，往往需要在同一频点的信号中同时播发满足不同要求的复合电文。如：按一定信息速率播发基本电文，满足系统基本服务性能或公开服务性能的要求，同时播发信息速率相同或不同的扩展电文，满足系统附加服务性能或非公开服务性能的要求。由于扩展电文信号不一定完全公开，系统要求设计的复合电文信号，可保证基本电文用户在不知扩展电文信号存在与否的情况下，性能完好地接收复合电文信号中的基本电文。
对于采用直序扩频信号体制的通信、导航系统，播发电文的速率一般要小于扩频码周期的倒数。例如，美国的GPS L1C/A码的扩频码周期为1ms，导航电文的速率为50bps；WAAS卫星导航星基增强系统的扩频码周期为1ms，导航电文的速率为500sps。如果要提升电文播发速率，就要缩短扩频码的码长，或一个码周期内极性翻转多次，这样会降低信号接收和跟踪时的相关特性，损坏信号接收性能。
另一方面，对于同样采用了码移键控调制方式(简称CSK调制方式)播发电文的日本QZSS准天顶卫星导航系统，为了给CSK解调提供必须的扩频码码片和码周期时间信息，QZSS系统在播发CSK调制电文的L6信号中，设计了不播发电文的专用导频通道，导频通道信号与电文播发信号采用TDM时分复用方式组合，在同一载波相位中播发。
为了降低CSK解调误码率，一种直观的解决办法是对由给定信息符号调制 的扩频码序列，重复播发多次，提高单个调制符号的信号播发能量。同时，为了避免由于重复播发引起信息速率下降的问题，同比例地提高单个调制符号所占的信息比特数，保持信息速率不变。对于这样的CSK调制方式，本专利称为重复移相码移键控调制方式(简称R-CSK调制方式)。
通常，为了工程实现的方便，CSK/R-CSK调制一般采用相位顺序超前或相位顺序滞后的方式，给调制信息符号一一指定不同的PRN(伪随机噪声)相位，将调制信息映射到PRN码的一段连续相位区域。当存在多径干扰时，采用此种相位配置的CSK/R-CSK调制信号容易在信号解调器的输出端产生较大的相关峰旁瓣，干扰CSK/R-CSK解调判决，增加CSK/R-CSK解调误码率。
发明内容
本发明所要解决的技术问题是提供一种能够有效解决通信、导航系统应用中播发多类型电文服务需求、且具备良好多径抑制性能的基于相位非连续R-CSK调制的电文信号播发控制方法及装置。
为了解决上述技术问题，本发明采用以下技术方案：
本发明提供一种基于相位非连续R-CSK调制的电文信号播发方法，包括：
将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；
将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位(以码片为单位)间的相位间隔为固定值，且相差两个码片以上；
对同相I支路的基本电文基带信号与正交Q支路的扩展电文基带信号进行IQ正交调制，得到中频载波信号，再针对中频载波信号进行上变频处理，获得 射频载波信号，最后经功率放大处理，构成双速率复合电文信号，交由发射天线进行播发。
作为本发明的一种优选技术方案：假设相位间隔为Z，所述待调制电文中的任一数值表示为i时，则伪随机扩频序列的初始相位为PRN(i*Z)；i＝0～M-1，M为所述待调制电文信息符号个数，Z取值满足大于等于2码片且M*Z小于等于一个伪随机扩频序列周期对应的码片数。
作为本发明的一种优选技术方案：上述基于相位非连续R-CSK调制的电文信号播发方法中，同相I支路上，按如下方法构建同相I支路基带信号：
针对基本电文进行信道编码得到编码后的比特流D B(t)；
根据时序发生器所提供的基本电文扩频码周期时钟和Chip时钟，由基本电文扩频码发生器产生基本电文扩频码C B(t)，对所获基本电文对应的比特流D B(t)进行BPSK-DSSS直序扩频调制，更新基本电文所对应的比特流为C B(t)·D B(t)；
基于预设基本电文的功率配比系数A I，按S I(t)＝A I·C B(t)·D B(t)，获得同相I支路基带信号S I(t)。
作为本发明的一种优选技术方案：上述基于相位非连续R-CSK调制的电文信号播发方法中，正交Q支路上，按如下方法构建正交Q支路基带信号：
针对扩展电文进行信道编码得到编码后的比特流；
根据时序发生器提供的扩展电文符号时钟，对扩展电文编码后对应的比特流进行1->K R bit串/并转换，得到并行数据流；其中每K R bit并行数据持续时间、即符号时间长度等于扩展电文扩频码周期时间的N倍；
根据时序发生器提供的扩展电文扩频码周期时钟，由相位选择模块按照预设的相位等间隔非连续映射关系，产生并行数据流所对应的相位偏移量；
根据时序发生器所提供的扩展电文码周期时钟、Chip时钟、以及并行数据流所对应的相位偏移量，由扩展电文扩频码发生器产生扩展电文扩频码，基于所述扩展电文扩频码重复多次、或重复零次即不重复进行相位等间隔非连续配置码移键控调制，获得调制后的扩展电文扩频码信号
Figure PCTCN2019126147-appb-000001
并结合预设扩展 电文功率配比系数A Q，按
Figure PCTCN2019126147-appb-000002
获得伪随机扩频序列S Q(t)，即正交Q支路基带信号S Q(t)，其中，伪随机扩频序列的码相位受扩展电文控制，(A I) 2+(A Q) 2＝1。其中，当基于所述扩展电文扩频码不重复进行相位等间隔非连续配置码移键控调制时，这种调制方式即为CSK调制。
作为本发明的一种优选技术方案：所述扩展电文符号时钟为扩展电文码周期时钟的整数倍，并与扩展电文码周期时钟同步。
本发明还提供一种基于相位非连续R-CSK调制的电文信号播发装置，包括：
第一调制单元，用于将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；
第二调制单元，用于将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位(以码片为单位)间的相位间隔为固定值，且相差两个码片以上；
载波调制单元，用于对同相I支路的基本电文基带信号与正交Q支路的扩展电文基带信号进行IQ正交调制，得到中频载波信号，再针对中频载波信号进行上变频处理，获得射频载波信号；
发送单元，用于对射频载波信号经功率放大处理，构成双速率复合电文信号进行播发。
作为本发明的一种优选技术方案：假设相位间隔为Z，所述待调制电文中的任一数值表示为i时，则伪随机扩频序列的初始相位为PRN(i*Z)；i＝0～M-1，M为所述待调制电文信息符号个数，Z取值满足大于等于2码片且M*Z小于等于一个伪随机扩频序列周期对应的码片数。
作为本发明的一种优选技术方案，本发明实施例的基于相位非连续R-CSK调制的电文信号播发装置中，所述第一调制单元包括：
编码子单元，用于针对基本电文进行信道编码得到编码后的比特流D B(t)；
第一扩频调制子单元，用于根据时序发生器所提供的基本电文扩频码周期时钟和Chip时钟，由基本电文扩频码发生器产生基本电文扩频码C B(t)，对所获基本电文对应的比特流D B(t)进行BPSK-DSSS直序扩频调制，更新基本电文所对应的比特流为C B(t)·D B(t)；
基带信号生成子单元，用于基于预设基本电文的功率配比系数A I，按S I(t)＝A I·C B(t)·D B(t)，获得同相I支路基带信号S I(t)。
作为本发明的一种优选技术方案，本发明实施例的基于相位非连续R-CSK调制的电文信号播发装置中，所述第二调制单元包括：
编码子单元，用于针对扩展电文进行信道编码得到编码后的比特流；
串/并转换子单元，用于根据时序发生器提供的扩展电文符号时钟，对扩展电文编码后对应的比特流进行1->K R bit串/并转换，得到并行数据流；其中每K R bit并行数据持续时间、即符号时间长度等于扩展电文扩频码周期时间的N倍；
相位偏移子单元，用于根据时序发生器提供的扩展电文扩频码周期时钟，由相位选择模块按照预设的相位等间隔非连续映射关系，产生并行数据流所对应的相位偏移量；
第二扩频调制子单元，用于根据时序发生器所提供的扩展电文码周期时钟、Chip时钟、以及并行数据流所对应的相位偏移量，产生扩展电文扩频码，基于所述扩展电文扩频码重复多次、或重复零次即不重复进行相位等间隔非连续配置码移键控调制，获得调制后的扩展电文扩频码信号
Figure PCTCN2019126147-appb-000003
并结合预设扩展电文功率配比系数A Q，按
Figure PCTCN2019126147-appb-000004
获得伪随机扩频序列S Q(t)，即正交Q支路基带信号S Q(t)，其中，伪随机扩频序列的码相位受扩展电文控制，(A I) 2+(A Q) 2＝1。其中，当基于所述扩展电文扩频码不重复进行相位等间隔非连续配置码移键控调制时，这种调制方式即为CSK调制。
作为本发明的一种优选技术方案，所述扩展电文符号时钟为扩展电文码周期时钟的整数倍，并与扩展电文码周期时钟同步。
本发明的基于相位非连续R-CSK调制的电文信号播发方法与现有技术相比，具有以下优异效果：
本发明的基于相位非连续R-CSK调制的电文信号播发方法，采用IQ两路正交调制，其中同相I支路上采用BPSK二进制相移键控载波调制，基带信号为经过DSSS直序扩频的基本电文；正交Q支路上采用BPSK二进制相移键控载波调制，基带信号为经过多次重复、或重复零次即不重复移相的相位等间隔非连续配置码移键控调制的伪随机扩频序列，伪随机序列的码相位受播发的扩展电文控制；在扩频码长或周期相同的条件下，采用CSK调制方式，可以获得比DSSS直序扩频更高的电文播发速率；本发明由于采用多次重复移相的码移键控调制，与常规CSK调制系统相比，在播发有效信息速率相同的情况下，可有效提升接收机的解调性能；可以在提高CSK调制信息传输速率的同时，保持接收端信号功率密度不变，避免大幅增加接收端解调CSK电文的软硬件成本和功耗；本发明通过为调制信息符号一一指定不同的PRN相位，相位之间不连续，彼此相差一个固定的相位间隔。当多径干扰信号的延迟时间处在两个指定相位之间时，将不再产生相关峰旁瓣干扰，从而获得更好的多径干扰抑制性能。本发明由于采用相位等间隔非连续配置R-CSK调制，与常规相位连续配置CSK/R-CSK调制系统相比，可以有效抑制延迟时间在指定相位间的多径信号干扰，提高接收机的解调性能；本发明由于将基本电文和扩展电文分别放在正交的IQ支路上，可以为电文速率不同的基本电文信号和扩展电文信号配置不同的功率比，提高了信号播发效率；由于IQ支路正交，载波相位相差90度，可有效避免大功率的扩展电文信号对基本电文信号接收性能的影响；在I支路上播发BPSK信号，既可为Q支路提供CSK解调所需的同步信息，又能有效播发基本电文；由于基本电文信号与扩展电文信号扩频码不同且载波正交，只需接收基本电文的系统用户无需考虑扩展电文的存在，可以简化基本电文接收机的设计，降低基本电文接收机的成本。本发明方法适用于通信、导航系统设计等领域。
附图说明
图1是本发明的基于相位非连续R-CSK调制的电文信号播发方法中播发方法框图；
图2为I支路基带信号各分量的时序关系；
图3为Q支路基带信号各分量的时序关系；
图4为复数基带信号的星座图；
图5为基本电文信号接收机构成图；
图6为双速率电文信号相干接收机构成图；
图7为双速率电文信号非相干接收机构成图；
图8为梳状滤波器构成图；
图9为多径干扰信号形成原理框图；
图10(a)为常规CSK/R-CSK调制信息与PRN码相位映射关系图(相位顺序超前)；
图10(b)为常规CSK/R-CSK调制信息与PRN码相位映射关系图(相位顺序滞后)；
图11为多径信号影响机理分析框图；
图12为常规CSK/R-CSK调制多径信号影响分析图；
图13为多径干扰信号存在与否时常规CSK/R-CSK调制的信息传输理论误码率曲线图；
图14为本发明提出的相位非连续R-CSK调制信息与PRN码相位映射关系图；
图15为本发明提出的相位非连续CSK/R-CSK调制多径信号影响分析图；
图16为多径场景下本发明的相位非连续R-CSK的信息传输误码率与常规R-CSK信息误码率的仿真效果对比图；
图17为本发明提出的相位非连续R-CSK解调匹配滤波器电路原理框图；
图18为本发明实施例的基于相位非连续R-CSK调制的电文信号播发装置的组成结构示意图。
具体实施方式
下面结合说明书附图对本发明的具体实施方式作进一步详细的说明。
本发明的基于相位非连续R-CSK调制的电文信号播发方法，在实际应用当中，如图1所示，应用IQ两路正交调制，实现双速率复合电文信号的播发。
将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；
将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位(码片单位)间的相位间隔为固定值，且相差两个码片以上；
对于上述同相I支路基带信号与正交Q支路基带信号的构建，分别按如下各个方法实现。
其中，针对同相I支路基带信号的构建，具体方法如下：
针对基本电文进行信道编码得到编码后的比特流D B(t)；
根据时序发生器所提供的基本电文扩频码周期时钟和Chip时钟，由基本电文扩频码发生器产生基本电文扩频码C B(t)，对所获基本电文对应的比特流D B(t)进行BPSK-DSSS直序扩频调制，更新基本电文所对应的比特流为C B(t)·D B(t)；
如图2所示，给出了同相I支路基带信号各分量的时序关系，基本电文时钟 时间长度为T BS＝1ms，基本电文的信息经分组编码和信道编码后形成速率R B＝1/T BS＝1kbps、取值正负1的比特流D B(t)。基本电文扩频码C B(t)码速率为10.23MHz，基本电文扩频码周期时间长度T BC＝1ms,取值正负1。电文与伪随机序列的对应关系为1->“PRN(0)+”,-1->“PRN(0)-”，其中，“PRN(0)+”表示初始相位为0的正极性伪随机序列，“PRN(0)-”表示初始相位为0的负极性伪随机序列。
基于预设基本电文的功率配比系数A I，按S I(t)＝A I·C B(t)·D B(t)，获得同相I支路基带信号S I(t)。
针对正交Q支路基带信号的构建，具体方法如下：
针对扩展电文进行信道编码得到编码后的比特流；
根据时序发生器提供的扩展电文符号时钟，对扩展电文编码后对应的比特流进行1->K R bit串/并转换，得到并行数据流；其中每K R bit并行数据持续时间、即符号时间长度等于扩展电文扩频码周期时间的N倍；
根据时序发生器提供的扩展电文扩频码周期时钟(图1中简称为扩展电文码周期时钟)，由相位选择模块按照预设的相位等间隔非连续映射关系，产生并行数据流所对应的相位偏移量。在此，设扩展电文扩频码周期长度为L码片，信息符号K R比特、对应的信息符号个数为
Figure PCTCN2019126147-appb-000005
配置的相位间隔为Z，其中Z为大于1的整数。则并行数据流所对应的相位偏移量
Figure PCTCN2019126147-appb-000006
其中i＝0,1,...,M-1，Z与M满足M*Z≤L的约束；
图3给出了正交Q支路信号各分量的时序关系，扩展电文符号时钟时间长度T ES,R等于扩展电文扩频码周期时钟时间长度T EC的N倍，采用K R bit表示一个符号，扩展电文信息播发速率R E＝K R/T ES,R。不失一般性，为后续说明方便，设定扩展电文扩频码周期时钟时间长度T EC＝1ms，重复移相2次(N＝2)，扩展电文符号时钟时间长度T ES,R＝2ms,采用6bit表示一个符号(K R＝6)，电文取值范围为0～63，相位间隔Z＝64码片，对应的相位偏移量为64*i、i＝0,1,...,63，则扩展电文信息播发速率R E,R＝6/T ES,R＝3kbps，以相同的相位重复调制2个相同的伪随机序列(即图3中6bit电文(i)与N个PRN(i*Z)对应)，将2个相位偏 移量相同的伪随机序列顺序连接，组成新的调制符号，完成多次重复移相的相位等间隔非连续配置码移键控调制。图3中6bit电文(i)与PRN(i*Z)对应只是本发明的一个实施例，也可以为其它对应关系。
根据时序发生器所提供的扩展电文码周期时钟、Chip时钟、以及并行数据流所对应的相位偏移量，由扩展电文扩频码发生器产生扩展电文扩频码，基于所述扩展电文扩频码重复多次、或重复零次即不重复进行相位等间隔非连续配置码移键控调制，获得调制后的扩展电文扩频码信号
Figure PCTCN2019126147-appb-000007
并结合预设扩展电文功率配比系数A Q，按
Figure PCTCN2019126147-appb-000008
获得伪随机扩频序列S Q(t)，即正交Q支路基带信号S Q(t)，其中，伪随机扩频序列的码相位受扩展电文控制。
(A I) 2+(A Q) 2＝1
如图4所示，给出了当设定
Figure PCTCN2019126147-appb-000009
时，复数基带信号的星座图，这里只给出了一个示例，功率配比关系不限于此对应关系。
本申请实施例中，当基于所述扩展电文扩频码不重复进行相位等间隔非连续配置码移键控调制时，这种调制方式即为CSK调制。
在本发明的本示例中，相位间隔Z为大于1的整数。设多径干扰信号的延迟时间为τ m(码片单位)，则多径干扰信号的码相位为
Figure PCTCN2019126147-appb-000010
其中
Figure PCTCN2019126147-appb-000011
为信号发射端按照预设的相位映射关系设置的码相位。当多径干扰信号的延迟时间超出1个扩频码码片、且小于Z-1个码片时，多径干扰信号的码相位将不会与预设的任何码相位相同，也就不会在接收机CSK/R-CSK信号解调输出端产生任何相关峰旁瓣干扰。例如，扩频码码片时间为1微秒时，相位间隔设置为64的CSK/R-CSK调制信号将不受延迟路径为30～1890米的多径干扰信号影响。相位间隔Z越大，可抑制的多径干扰信号延迟范围越广，在M*Z≤L不等式的约束下，等间隔相位配置可以获得最大的多径干扰信号延迟抑制范围。
在本发明的本示例中，不考虑基本电文和扩展电文信道编码差异的情况下，为保证在接收端获得同等的电文解调性能，一般对电文速率高的支路配置更高的信号播发功率。
两个支路采用不同的扩频码序列。当电文速率不同时，IQ支路可以分配不同的发射功率，使得接收端接收到的基本电文和扩展电文具有同等接收性能。播发信号IQ两路的扩频码和电文彼此保持同步。
则对于同相I支路基带信号S I(t)与正交Q支路基带信号S Q(t)的复数表达式如下：
S(t)＝S I(t)+jS Q(t)
其中，j为虚数。
然后，针对同相I支路基带信号与正交Q支路基带信号，进行IQ正交调制得到中频载波信号，再针对中频载波信号进行上变频处理，获得射频载波信号，最后经功率放大处理，构成双速率复合电文信号，交由发射天线进行播发。
这里双速率复合电文信号的射频发射信号表达如下：
Figure PCTCN2019126147-appb-000012
其中，P s表示复合电文射频信号发射总功率，f c表示发射信号频率。
本发明设计的基于相位非连续R-CSK调制的电文信号播发方法中，将基本电文和扩展电文分别放在正交的IQ支路上，提升扩展电文的播发速率只需提升扩展电文信号的功率，提高了信号播发效率；IQ支路正交，载波相位相差90度，可有效避免大功率的扩展电文信号对基本电文信号接收性能的影响；在I支路上播发的BPSK信号，既可为Q支路提供CSK解调所需的同步信息，又能有效播发基本电文；采用多次重复、或重复零次即不重复移相的相位等间隔非连续配置码移键控调制技术，可以有效提升信息播发速率，进一步改进信号播发效率，同时有效抑制多径干扰信号。
针对上述设计的基于相位非连续R-CSK调制的电文信号播发方法，本发明进一步设计了双速率电文信号接收方法，包括基于相位非连续R-CSK调制的电 文信号中的基本电文接收方法、扩展电文相干解调接收方法、以及扩展电文非相干解调接收方法；其中，基本电文接收方法，如图5所示，具体如下：
接收机天线接收的射频载波信号经过射频前端(RF Front-End)处理输出数字中频信号；数字中频信号首先与载波环复制的载波混频输出正交的IQ两路基带信号，IQ两路基带信号分别与基本电文扩频码发生器复制的基本电文扩频码做相关运算，获得IQ两路相关结果；随后，IQ两路相关结果作为鉴相滤波模块的输入，鉴相滤波模块计算载波鉴相误差和码鉴相误差，并对鉴相误差进行滤波，滤波结果分别用来调节载波NCO(Carrier NCO)和码NCO(Code NCO)，使Carrier NCO所输出的载波与接收载波保持一致，以及使基本电文扩频码发生器在Code NCO控制下复制的基本电文扩频码与接收基本电文扩频码保持一致，保证下一时刻接收信号中的载波和扩频码在跟踪环路中仍被彻底剥离；同时I支路相关器输出的相关结果经基本电文判决模块判决输出基本电文数据比特。
基于相位非连续R-CSK调制的电文信号中扩展电文相干解调接收方法，如图6所示，具体如下：
在解调基本电文时，将同步后所获与接收信号同步的扩展电文扩频码周期时钟、Chip时钟传递给扩展电文扩频码发生器和相干匹配滤波模块，将扩展电文符号时钟和扩展电文扩频码周期时钟传递给梳状滤波器；Q支路基带信号传递给梳状滤波器，梳状滤波器将同一符号内的N组伪随机序列数据叠加为1组伪随机序列数据；
其中，梳状滤波器构成框图如图8所示：梳状滤波器在扩展电文扩频码周期时钟的控制下，将输入数据顺序时延N-1次，每次时延扩展电文扩频码周期时间T EC秒，然后将N-1次时延数据与输入数据叠加后送给数据截取模块；其次，数据截取模块在扩展电文符号时钟和扩展电文扩频码周期时钟的控制下，截取输入数据流，输出同一符号内叠加了N次的数据，数据时间长度为扩展电文扩频码周期时间T EC秒。截取数据输送给相干匹配滤波模块。
然后，相干匹配滤波模块在扩展电文符号时钟和扩展电文扩频码周期时钟的控制下，将接收到的时间长度为T EC的数据块与扩展电文扩频码发生器在扩展电文扩频码周期时钟和Chip时钟控制下生成的扩展电文扩频码进行相关匹配计算，相关结果输出给相关峰搜索模块，搜索相关峰对应的本地扩展电文扩频码相位，并将相位转换为比特数据输出；
最后，将相关峰搜索模块输出的比特数据经过信道译码模块得到传输的扩展电文数据。
基于相位非连续R-CSK调制的电文信号中扩展电文非相干解调接收方法，如图7所示，具体如下：
在解调基本电文时，将同步后所获与接收信号同步的扩展电文扩频码周期时钟、Chip时钟传递给扩展电文扩频码发生器和非相干匹配滤波模块，将扩展电文符号时钟和扩展电文扩频码周期时钟传递给梳状滤波器；基带IQ两路信号传递给梳状滤波器，梳状滤波器将同一符号内的N组伪随机序列数据叠加为1组伪随机序列数据；
其中，梳状滤波器构成框图如图8所示：梳状滤波器在扩展电文扩频码周期时钟的控制下，将输入数据顺序时延N-1次，每次时延扩展电文扩频码周期时间T EC秒，然后将N-1次时延数据与输入数据叠加后送给数据截取模块；其次，数据截取模块在扩展电文符号时钟和扩展电文扩频码周期时钟的控制下，截取输入数据流，输出同一符号内叠加了N次的数据，数据时间长度为扩展电文扩频码周期时间T EC秒。截取数据输送给非相干匹配滤波模块。
然后，非相干匹配滤波模块在扩展电文符号时钟和扩展电文扩频码周期时钟的控制下，将接收到的时间长度为T EC的数据块与扩展电文扩频码发生器在扩展电文扩频码周期时钟和Chip时钟控制下生成的扩展电文扩频码进行相关匹配计算，相关结果输出给相关峰搜索模块，搜索相关峰对应的本地扩展电文扩频码相位，并将相位转换为比特数据输出；
最后，将相关峰搜索模块输出的比特数据经过信道译码模块得到传输的扩 展电文数据。
图9给出了多径干扰信号形成的原理框图，通常在接收机工作过程中，除了能够收到卫星发射的直达信号，还会同时接收到由于其他物体(如建筑物等)反射的同一卫星发射的信号，即多径信号。假设卫星信号发射时刻为t 0，接收机接收到直达信号的时刻t 1应等于信号发射时刻t 0加上信号传播时间延迟τ 1，即t 1＝t 0+τ 1，接收机接收到多径信号的时刻t 2等于信号发射时刻t 0加上信号到达建筑物的传播时间延迟τ 2和建筑物到接收机的传播时间延迟τ 3，即t 2＝t 0+τ 2+τ 3。显然，多径信号到达接收机的时间延迟要长于直达信号，并且由于反射损失，及空间传播损失，多径信号功率要弱于直达信号功率。
常规的CSK/R-CSK调制一般采用相位顺序超前或相位顺序滞后的方式，给调制信息符号一一指定不同的PRN相位，将调制信息映射到PRN码的一段连续相位区域，图10(a)和图10(b)以CSK(6)为例，分别给出了相位顺序超前和相位顺序滞后的相位映射关系图。
当存在多径干扰时，整数码片时间延迟的多径信号，容易在CSK/R-CSK信号解调器的输出端造成较大的相关峰旁瓣，干扰CSK/R-CSK解调判决，增加CSK/R-CSK解调误码率。以图10(a)所示的常规CSK/R-CSK调制信息与PRN码相位映射关系图(相位顺序超前)为例，针对CSK(6)调制，调制信息为30，多径时间延迟为5个码片，多径信号功率较直达信号衰减3dB、与直达信号载波相位差0度的情况进行仿真，图11给出了上述仿条件下的多径影响机理分析图，从中可以看出，由于此多径信号延迟与调制信息25的映射相位一致，在CSK/R-CSK信号解调输出端除了直达信号形成的相关峰之外，还存在由于多径信号形成的较大的相关峰旁瓣，这将严重干扰CSK/R-CSK解调判决。
不同码片延迟的多径信号对于不同调制信息符号的影响也会有所不同。同 样以图10(a)所示的常规CSK/R-CSK调制信息与PRN码相位映射关系图(相位顺序超前)为例，针对CSK(6)调制，当调制电文为0时，由于不会出现由多径信号形成的较大的相关峰旁瓣，所以不会受到多径信号的影响，如图12(a)所示；当调制电文为30时，在多径信号时间延迟为1～30个码片时，均会出现由多径信号形成的较大的相关峰旁瓣，所以会受到时间延迟为1～30个码片的多径信号的影响，如图12(b)所示；当调制电文为63时，在多径信号时间延迟为1～63个码片时，均会出现由多径信号形成的较大的相关峰旁瓣，所以会受到时间延迟为1～63个码片的多径信号的影响，如图12(c)所示；从图12还可以看出，常规CSK(6)调制信号会受到时间延迟1～63码片的多径信号的影响，当多径信号时间延迟大于63个码片时，由于在此延迟范围内不存在调制信息的映射相位，也就不会产生由多径信号引起的相关值干扰，所以将不受此多径信号的影响。
从解调误码率的角度可以更直观地说明常规CSK/R-CSK调制受多径干扰的影响，针对多径干扰信号存在与否时，CSK/R-CSK的误码率性能进行理论计算，相关符号及对应关系约定如下：
无多径干扰时，常规CSK/R-CSK调制的相干解调符号误码率计算公式如下：
Figure PCTCN2019126147-appb-000013
其中，E s/N 0＝E b/N 0×K＝E b/N 0×log 2M，K为每个符号的比特数，进制M＝2 K。
换算为信息比特误码率的公式如下：
Figure PCTCN2019126147-appb-000014
在CSK/R-CSK解调时，由于整数码片延迟多径干扰信号的存在，在进行匹配滤波时，多径信号会形成一个较大的相关值输出R M，设与最大相关峰值R max的比值为μ，μ的大小受载波相位、多径信号延迟大小以及多径信号功率影 响。存在多径干扰时，常规CSK/R-CSK调制的相干解调符号误码率计算公式如下：
Figure PCTCN2019126147-appb-000015
换算为信息比特误码率的公式如下：
Figure PCTCN2019126147-appb-000016
图13给出了多径干扰信号存在与否时常规CSK/R-CSK调制的信息传输理论误码率曲线图，其中，曲线“理论-常规CSK/R-CSK-无多径”为无多径信号时的相干解调误码率曲线；“理论-常规CSK/R-CSK-有多径”为存在功率较直达信号衰减3dB、延迟时间为整数码片(在相位映射范围内)、与直达信号载波相位差0度(即μ＝0.707)的多径信号时的相干解调误码率曲线。从图13可以清楚地看出，多径干扰存在时，相干解调误码率明显高于无多经干扰时。
图14给出了其中一种本发明提出的相位非连续R-CSK调制信息与PRN码相位映射关系图。以CSK(6)调制为例，假定相位间隔Z＝64，信息符号i取值0～63，则对应扩频码初始相位为PRN(i*Z)。
为了更直观地体现本发明提出的相位非连续CSK/R-CSK调制相对于常规CSK/R-CSK调制的有效性，依然从相关峰旁瓣和解调误码率两个方面进行分析。
以CSK(6)为例，采用本发明提出的相位非连续的方式，针对调制信息符号为30、多径时间延迟1～256码片、多径信号功率较直达信号衰减3dB、与直达信号载波相位差0度的情况进行仿真，为了便于仿真，这里采用相位间隔Z＝64的等间隔相位配置。本发明提出的相位非连续CSK/R-CSK调制多径信号影响分析如图15所示。从图中可以看出，当多径延迟时间≥1码片且≤63码片时，由于 在此延迟范围内不存在调制信息的映射相位，也就不会产生由多径信号引起的相关值干扰，因此将不受此范围内的多径信号的影响，当扩频码码片时间为1微秒时，此段延迟时间对应30～1890米范围。当多径延迟时间≥64码片时，虽然仍会受到多径信号引起的相关值的干扰，但仅仅出现在多径时间延迟为相位间隔Z＝64的整数倍码片处，多径信号影响得到分散，即仅受到时间延迟为相位间隔Z的整数码片多径信号的影响。并且随着多径信号时间延迟的增加，信号功率逐渐减弱，时间延迟大于63个码片的多径信号的影响已经很小，所以本发明的相位非连续CSK/R-CSK调制能够有效抑制多径干扰信号的影响。
同样从解调误码率的角度可以更直观地说明本发明提出的相位非连续R-CSK调制较常规CSK/R-CSK调制在抑制多径干扰方面的有效性。为仿真计算方便，不失一般性，以R-CSK(6,2)为例，针对采用相位间隔为Z＝64的等间隔相位非连续配置，多径延迟时间为1个码片，多径信号功率较直达信号衰减3dB、与直达信号载波相位差0度的情况进行仿真。该多径场景下本发明的相位非连续R-CSK的信息传输误码率与常规R-CSK信息误码率的仿真效果对比图如图16所示。可以看出，在存在1码片多径干扰情况下，本发明的相位非连续R-CSK的信息传输误码率与理论曲线基本一致，明显优于常规R-CSK调制。
此外，图17给出了本发明提出的相位非连续R-CSK调制的一种解调匹配滤波器电路原理框图，相比于常规CSK/R-CSK调制，本发明提出的相位非连续R-CSK调制几乎不增加信号解调运算成本。
图18为本发明实施例的基于相位非连续R-CSK调制的电文信号播发装置的组成结构示意图，如图18所示，本发明实施例的基于相位非连续R-CSK调制的电文信号播发装置，包括：
第一调制单元180，用于将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；
第二调制单元181，用于将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位(码片单位)间的相位间隔为固定值，且相差两个码片以上；
载波调制单元182，用于对同相I支路的基本电文基带信号与正交Q支路的扩展电文基带信号进行IQ正交调制，得到中频载波信号，再针对中频载波信号进行上变频处理，获得射频载波信号；
发送单元183，用于对射频载波信号经功率放大处理，构成双速率复合电文信号进行播发。
作为本发明的一种优选技术方案：假设相位间隔为Z，所述待调制电文中的任一数值表示为i时，则伪随机扩频序列的初始相位为PRN(i*Z)；i＝0～M-1，M为所述待调制电文信息符号个数，Z取值满足大于等于2码片且M*Z小于等于一个伪随机扩频序列周期对应的码片数。
作为本发明的一种优选技术方案，本发明实施例的基于相位非连续R-CSK调制的电文信号播发装置中，所述第一调制单元180包括：
编码子单元，用于针对基本电文进行信道编码得到编码后的比特流D B(t)；
第一扩频调制子单元，用于根据时序发生器所提供的基本电文扩频码周期时钟和Chip时钟，由基本电文扩频码发生器产生基本电文扩频码C B(t)，对所获基本电文对应的比特流D B(t)进行BPSK-DSSS直序扩频调制，更新基本电文所对应的比特流为C B(t)·D B(t)；
基带信号生成子单元，用于基于预设基本电文的功率配比系数A I，按S I(t)＝A I·C B(t)·D B(t)，获得同相I支路基带信号S I(t)；
作为本发明的一种优选技术方案，本发明实施例的基于相位非连续R-CSK 调制的电文信号播发装置中，所述第二调制单元181包括：
编码子单元，用于针对扩展电文进行信道编码得到编码后的比特流；
串/并转换子单元，用于根据时序发生器提供的扩展电文符号时钟，对扩展电文编码后对应的比特流进行1->K R bit串/并转换，得到并行数据流；其中每K R bit并行数据持续时间、即符号时间长度等于扩展电文扩频码周期时间的N倍；
相位偏移子单元，用于根据时序发生器提供的扩展电文扩频码周期时钟，由相位选择模块按照预设的相位等间隔非连续映射关系，产生并行数据流所对应的相位偏移量；
第二扩频调制子单元，用于根据时序发生器所提供的扩展电文码周期时钟、Chip时钟、以及并行数据流所对应的相位偏移量，产生扩展电文扩频码，基于所述扩展电文扩频码重复多次、或重复零次即不重复进行相位等间隔非连续配置码移键控调制，获得调制后的扩展电文扩频码信号
Figure PCTCN2019126147-appb-000017
并结合预设扩展电文功率配比系数A Q，按
Figure PCTCN2019126147-appb-000018
获得伪随机扩频序列S Q(t)，即正交Q支路基带信号S Q(t)，其中，伪随机扩频序列的码相位受扩展电文控制，(A I) 2+(A Q) 2＝1。
作为本发明的一种优选技术方案，所述扩展电文符号时钟为扩展电文码周期时钟的整数倍，并与扩展电文码周期时钟同步。
本申请实施例中，当基于所述扩展电文扩频码不重复进行相位等间隔非连续配置码移键控调制时，这种调制方式即为CSK调制。
本发明的基于相位非连续R-CSK调制的电文信号播发方法与现有技术相比，具有以下优异效果：
本发明的基于相位非连续R-CSK调制的电文信号播发方法，采用IQ两路正交调制，其中同相I支路上采用BPSK二进制相移键控载波调制，基带信号为经过DSSS直序扩频的基本电文；正交Q支路上采用BPSK二进制相移键控载波调制，基带信号为经过多次重复、或重复零次即不重复移相的相位等间隔非连续配置码移键控调制的伪随机扩频序列，伪随机序列的码相位受播发的扩 展电文控制；在扩频码长或周期相同的条件下，采用CSK调制方式，可以获得比DSSS直序扩频更高的电文播发速率；本发明由于采用多次重复移相的码移键控调制，与常规CSK调制系统相比，在播发有效信息速率相同的情况下，可有效提升接收机的解调性能；可以在提高CSK调制信息传输速率的同时，保持接收端信号功率密度不变，避免大幅增加接收端解调CSK电文的软硬件成本和功耗；本发明通过为调制信息符号一一指定不同的PRN相位，相位之间不连续，彼此相差一个固定的相位间隔。当多径干扰信号的延迟时间处在两个指定相位之间时，将不再产生相关峰旁瓣干扰，从而获得更好的多径干扰抑制性能；本发明由于采用相位等间隔非连续配置R-CSK调制，与常规相位连续配置CSK/R-CSK调制系统相比，可以有效抑制延迟时间在指定相位间的多径信号干扰，提高接收机的解调性能；本发明由于将基本电文和扩展电文分别放在正交的IQ支路上，可以为电文速率不同的基本电文信号和扩展电文信号配置不同的功率比，提高了信号播发效率；由于IQ支路正交，载波相位相差90度，可有效避免大功率的扩展电文信号对基本电文信号接收性能的影响；在I支路上播发BPSK信号，既可为Q支路提供CSK解调所需的同步信息，又能有效播发基本电文；由于基本电文信号与扩展电文信号扩频码不同且载波正交，只需接收基本电文的系统用户无需考虑扩展电文的存在，可以简化基本电文接收机的设计，降低基本电文接收机的成本。本发明方法适用于通信、导航系统设计等领域。
上面结合附图对本发明的实施方式作了详细说明，但是本发明并不限于上述实施方式，在本领域普通技术人员所具备的知识范围内，还可以在不脱离本发明宗旨的前提下做出各种变化。

Claims (10)

  1. 一种基于相位非连续R-CSK调制的电文信号播发方法，其特征在于：所述方法包括：
    将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；
    将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位间的相位间隔为固定值，且相差两个码片以上；
    对同相I支路的基本电文基带信号与正交Q支路的扩展电文基带信号进行IQ正交调制，得到中频载波信号，再针对中频载波信号进行上变频处理，获得射频载波信号，最后经功率放大处理，构成双速率复合电文信号，交由发射天线进行播发。
  2. 根据权利要求1所述的基于相位非连续R-CSK调制的电文信号播发方法，其特征在于：
    相位间隔为Z，所述待调制电文中的任一数值表示为i时，则伪随机扩频序列的初始相位为PRN(i*Z)；i＝0～M-1，M为所述待调制电文信息符号个数，Z取值满足大于等于2码片且M*Z小于等于一个伪随机扩频序列周期对应的码片数。
  3. 根据权利要求1或2所述的基于相位非连续R-CSK调制的电文信号播发方法，其特征在于：所述构建同相I支路基带信号，包括：
    针对基本电文进行信道编码得到编码后的比特流D B(t)；
    根据时序发生器所提供的基本电文扩频码周期时钟和Chip时钟，由基本电文扩频码发生器产生基本电文扩频码C B(t)，对所获基本电文对应的比特流D B(t)进行BPSK-DSSS直序扩频调制，更新基本电文所对应的比特流为C B(t)·D B(t)；
    基于预设基本电文的功率配比系数A I，按S I(t)＝A I·C B(t)·D B(t)，获得同相I支路基带信号S I(t)。
  4. 根据权利要求1或2所述的基于相位非连续R-CSK调制的电文信号播发方法，其特征在于：所述构建正交Q支路基带信号，包括：
    针对扩展电文进行信道编码得到编码后的比特流；
    根据时序发生器提供的扩展电文符号时钟，对扩展电文编码后对应的比特流进行1->K R bit串/并转换，得到并行数据流；其中每K R bit并行数据持续时间、即符号时间长度等于扩展电文扩频码周期时间的N倍；
    根据时序发生器提供的扩展电文扩频码周期时钟，由相位选择模块按照预设的相位等间隔非连续映射关系，产生并行数据流所对应的相位偏移量；
    根据时序发生器所提供的扩展电文码周期时钟、Chip时钟、以及并行数据流所对应的相位偏移量，由扩展电文扩频码发生器产生扩展电文扩频码，基于所述扩展电文扩频码重复多次、或重复零次即不重复进行相位等间隔非连续配置码移键控调制，获得调制后的扩展电文扩频码信号
    Figure PCTCN2019126147-appb-100001
    并结合预设扩展电文功率配比系数A Q，按
    Figure PCTCN2019126147-appb-100002
    获得伪随机扩频序列S Q(t)，即正交Q支路基带信号S Q(t)，其中，伪随机扩频序列的码相位受扩展电文控制，(A I) 2+(A Q) 2＝1。
  5. 根据权利要求1或2所述的基于相位非连续R-CSK调制的电文信号播发方法，其特征在于：所述扩展电文符号时钟为扩展电文码周期时钟的整数倍，并与扩展电文码周期时钟同步。
  6. 一种基于相位非连续R-CSK调制的电文信号播发装置，其特征在于：所述装置包括：
    第一调制单元，用于将基本电文在同相I支路上进行调制，对基本电文进行BPSK-DSSS直序扩频，构建同相I支路基带信号；
    第二调制单元，用于将扩展电文在正交Q支路上进行调制，对扩展电文进行相位非连续R-CSK-DSSS直序扩频，构建正交Q支路基带信号；即对扩展电文进行调制时，为每一待调制符号确定伪随机扩频序列，通过对基础伪随机扩频序列采取循环移位的方式使数值相邻的两个待调制符号之间保持固定的相位间隔，所述固定的相位间隔至少大于一个伪随机扩频序列的码片相位，即任意数值相邻的两个调制符号分别对应的伪随机扩频序列的初始相位间的相位间隔为固定值，且相差两个码片以上；
    载波调制单元，用于对同相I支路的基本电文基带信号与正交Q支路的扩展电文基带信号进行IQ正交调制，得到中频载波信号，再针对中频载波信号进行上变频处理，获得射频载波信号；
    发送单元，用于对射频载波信号经功率放大处理，构成双速率复合电文信号进行播发。
  7. 根据权利要求6所述的基于相位非连续R-CSK调制的电文信号播发装置，其特征在于：
    相位间隔为Z，所述待调制电文中的任一数值表示为i时，则伪随机扩频序列的初始相位为PRN(i*Z)；i＝0～M-1，M为所述待调制电文信息符号个数，Z取值满足大于等于2码片且M*Z小于等于一个伪随机扩频序列周期对应的码片数。
  8. 根据权利要求6或7所述的基于相位非连续R-CSK调制的电文信号播发装置，其特征在于：所述第一调制单元包括：
    编码子单元，用于针对基本电文进行信道编码得到编码后的比特流D B(t)；
    第一扩频调制子单元，用于根据时序发生器所提供的基本电文扩频码周期时钟和Chip时钟，由基本电文扩频码发生器产生基本电文扩频码C B(t)，对 所获基本电文对应的比特流D B(t)进行BPSK-DSSS直序扩频调制，更新基本电文所对应的比特流为C B(t)·D B(t)；
    基带信号生成子单元，用于基于预设基本电文的功率配比系数A I，按S I(t)＝A I·C B(t)·D B(t)，获得同相I支路基带信号S I(t)。
  9. 根据权利要求6或7所述的基于相位非连续R-CSK调制的电文信号播发装置，其特征在于：所述第二调制单元包括：
    编码子单元，用于针对扩展电文进行信道编码得到编码后的比特流；
    串/并转换子单元，用于根据时序发生器提供的扩展电文符号时钟，对扩展电文编码后对应的比特流进行1->K R bit串/并转换，得到并行数据流；其中每K R bit并行数据持续时间、即符号时间长度等于扩展电文扩频码周期时间的N倍；
    相位偏移子单元，用于根据时序发生器提供的扩展电文扩频码周期时钟，由相位选择模块按照预设的相位等间隔非连续映射关系，产生并行数据流所对应的相位偏移量；
    第二扩频调制子单元，用于根据时序发生器所提供的扩展电文码周期时钟、Chip时钟、以及并行数据流所对应的相位偏移量，产生扩展电文扩频码，基于所述扩展电文扩频码重复多次、或重复零次即不重复进行相位等间隔非连续配置码移键控调制，获得调制后的扩展电文扩频码信号
    Figure PCTCN2019126147-appb-100003
    并结合预设扩展电文功率配比系数A Q，按
    Figure PCTCN2019126147-appb-100004
    获得伪随机扩频序列S Q(t)，即正交Q支路基带信号S Q(t)，其中，伪随机扩频序列的码相位受扩展电文控制，(A I) 2+(A Q) 2＝1。
  10. 根据权利要求6或7所述的基于相位非连续R-CSK调制的电文信号播发装置，其特征在于：所述扩展电文符号时钟为扩展电文码周期时钟的整数倍，并与扩展电文码周期时钟同步。
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