Expansion anti-interference measurement and control communication method

Abstract

The invention discloses a capacity-expanding anti-interference measurement and control communication method, which comprises the following steps of: 1, generating M alternative spread spectrum sequences; step 2, the transmitting end performs parallel combined spread spectrum, including parallel transmission, spread spectrum superposition and carrier modulation; wherein during spectrum spreading, in I and Q, any one alternative spectrum spreading sequence in one path is selected as a synchronization sequence, and all the remaining alternative spectrum spreading sequences are subjected to combined spectrum spreading; step 3, blind interference signal separation at a receiving end: at the receiving end, firstly carrying out carrier demodulation on all interference signals and measurement and control signals received by the array antenna, and then carrying out blind interference signal separation on observation signals after carrier demodulation to obtain separated expansion anti-interference measurement and control signals; and finally, recovering the expanded anti-interference measurement and control signal to obtain recovered data. According to the invention, parallel combination spread spectrum and blind interference signal separation processing are organically combined, so that the anti-interference capability of the measurement and control system can be ensured while the system capacity is improved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace measurement and control communications, and in particular to a capacity expansion and anti-interference measurement and control communication method. Background Art

[0002] Space tracking and control systems provide reliable and precise tracking, measurement, and command control for spacecraft launch and on-orbit operation, and are a crucial component of ensuring the proper functioning of spacecraft in aerospace engineering. With the rapid advancement of aerospace technology, spacecraft parameters are increasing, and the amount of data generated during operation is also increasing, creating an urgent need for high-bitrate data transmission. At the same time, the open nature of space tracking and control links makes them extremely susceptible to various types of electromagnetic interference, especially high-power malicious interference. Powerful adversaries can use platforms such as electronic warfare aircraft and accompanying small satellites to conduct electromagnetic interference on our satellite-to-ground tracking and control links. When the interference intensity exceeds the system's interference tolerance, the tracking and control signals cannot be properly demodulated, leading to the interruption of our tracking and control communication links, which could significantly impact command and decision-making in wartime. Therefore, satellite-to-ground tracking and control links must possess both high-bitrate data transmission capabilities and sufficient anti-interference capabilities to ensure efficient and reliable tracking and control data transmission.

[0003] Currently, measurement and control systems usually use a non-coherent spread spectrum measurement and control system to achieve anti-interference purposes. Although this system can improve the received signal-to-noise ratio to a certain extent, it still has the following shortcomings during use and needs to be improved:

[0004] 1. During the despreading process at the receiver, the spread spectrum communication system reduces the interference amplitude but widens the interference frequency band. In essence, it trades frequency resources for improved reliability.

[0005] 2. Conventional DSSS waveforms use a single pseudo-code spread spectrum sequence to broaden the signal, and each pseudo-code period carries only 1 bit of data. The frequency band utilization is low, and high-rate data transmission cannot be achieved.

[0006] 3. Traditional parallel combination spread spectrum technology can carry more bits of data per pseudo code cycle through the pseudo code combination relationship, improving the system bandwidth utilization. However, it has a problem that multiple pseudo codes share power, which will reduce the system interference tolerance. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a capacity expansion and anti-interference measurement and control communication method in response to the above-mentioned deficiencies in the existing technology. The capacity expansion and anti-interference measurement and control communication method organically combines parallel combination spread spectrum with blind interference signal separation processing, which can ensure the anti-interference capability of the measurement and control system while improving the system capacity.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A capacity expansion and anti-interference measurement and control communication method includes the following steps.

[0010] Step 1: Generate M candidate spreading sequences for use at the transmitter and receiver of the measurement and control link.

[0011] Step 2: Parallel combination spread spectrum at the transmitting end, including:

[0012] Step 2-1, Parallel transmission: At the transmitter, the transmitted data is converted from serial to parallel to form I and Q bit parallel transmission.

[0013] Step 2-2, Spreading and Superposition: Select any candidate spreading sequence in either I or Q as the synchronization sequence, and spread all remaining candidate spreading sequences. Next, superimpose the spread sequences of I and Q channels to form combined I and Q sequence signals. The synchronization sequence participates in the superposition of the corresponding channel sequences.

[0014] Step 2-3, carrier modulation: Carrier modulate the I and Q combined sequence signals to form an expanded anti-interference measurement and control waveform signal.

[0015] Step 3, blind signal separation at the receiving end: At the receiving end, all interference signals and measurement and control signals received by the array antenna are first carrier-demodulated, and then the observation signal after carrier demodulation is blindly separated from the interference signal to obtain the separated expanded anti-interference measurement and control signal; finally, the expanded anti-interference measurement and control signal is restored to obtain the recovered data.

[0016] In step 1, the generated M candidate spreading sequences have good autocorrelation and cross-correlation characteristics, namely PN1, PN2, ...PN M .

[0017] In step 2-2, suppose PN in the selected I channel is M As a synchronization sequence, in step 2-1, the sent data is set to N S , I and Q bits are parallel and N I Bit parallel and N Q Bit parallel; then:

[0018]

[0019] Where, represents the possibility of selecting r pseudocodes from M pseudocodes for combination, Indicates rounding down.

[0020] It represents the possibility of selecting r pseudocodes from M-1 pseudocodes for combination.

[0021] In step 2-2, N IThe method of bit parallel combination spread spectrum and superposition includes:

[0022] Step 2-2A1: Divide I-channel data into r bits and Two segments of bits.

[0023] Step 2-2A2, The communication data corresponding to the bit segment is PN1PN2…PN M-1 Data-spreading sequence mapping is performed to obtain r spreading sequences.

[0024] Step 2-2A3: Determine the polarities of the r spreading sequences according to the communication data corresponding to the r bit segments.

[0025] Step 2-2A4: Superimpose the selected r spreading sequences with polarity and the synchronization sequence PN M , get the I-way combined sequence signal d at time t I (t), the expression is:

[0026]

[0027] Where q j is the polarity of the j-th spreading sequence in channel I, which takes the value of +1 or -1; where 1≤j≤r.

[0028] PN j (t) is the jth spreading sequence in channel I at time t.

[0029] In step 2-2, N Q The method of bit parallel combination spread spectrum and superposition includes:

[0030] Step 2-2B1: Divide Q-channel data into r bits and Two segments of bits.

[0031] Step 2-2B2, The communication data corresponding to the bit segment is PN1PN2…PN M Data-spreading sequence mapping is performed to obtain r spreading sequences.

[0032] Step 2-2B3: Determine the polarities of the r spreading sequences according to the communication data corresponding to the r bit segments.

[0033] Step 2-2B4: Superimpose the selected r spread spectrum sequences with polarity to obtain the Q-channel combined sequence signal d at time t. Q (t), the expression is:

[0034]

[0035] Where q iis the polarity of the i-th spreading sequence in the Q channel, which takes the value of +1 or -1; where 1≤i≤r.

[0036] PN i (t) is the i-th spreading sequence in the Q channel at time t.

[0037] In step 2-3, the expression of the expanded anti-interference measurement and control waveform signal s(t) is:

[0038]

[0039] Where, d I (t) is the I-channel combined sequence signal at time t.

[0040] d Q (t) is the Q-path combined sequence signal at time t.

[0041] f c is the carrier frequency, a known value; is the carrier phase, a known value.

[0042] In step 3, the receiving end performs blind signal separation, including:

[0043] Step 3-1, Carrier demodulation: At the receiving end, the M R Each antenna demodulates the N interference signals and measurement and control signals received by each antenna to obtain M R Road observation signal.

[0044] Step 3-2, Blind signal separation: M R The observation signal is blindly separated from the interference signal to obtain N+1 separated signals.

[0045] Step 3-3, obtain the expansion anti-interference measurement and control signal: extract the I-channel data of each separated signal and compare it with the synchronization sequence PN M Do the correlation operation, get the estimated expansion anti-interference measurement and control signal through the maximum value judgment and polarity recovery, and use To express.

[0046] Step 3-4, recovery: First, extract the I and Q channel data from the expanded anti-interference measurement and control signal respectively, and restore the I and Q channel bits in parallel respectively, and then perform parallel-to-serial conversion to form recovered data.

[0047] In step 3-2, blind signal separation includes:

[0048] Step 3-2A, whitening pre-processing: M R The N+1 whitened signals are obtained by whitening preprocessing.

[0049] Step 3-2B, blind signal-jamming separation: perform blind signal-jamming separation on the N+1 whitened signals so that the separated signal y is similar to the source signal S.

[0050] In steps 3-4, recovery includes the following steps:

[0051] Step 3-4A: Extract I and Q channel data from the expanded anti-interference measurement and control signal respectively.

[0052] Step 3-4B, I-channel recovery: Compare I-channel data with PN1, PN2, ... PN M-1 Perform correlation operations respectively, and obtain the recovered N through maximum value judgment, polarity recovery and data-sequence inverse mapping. I Bit-parallel data.

[0053] Step 3-4C, Q-channel recovery: Compare Q-channel data with PN1, PN2, ... PN M Perform correlation operations respectively, and obtain the recovered N through maximum value judgment, polarity recovery and data-sequence inverse mapping. Q Bit-parallel data.

[0054] Step 3-4D, change N I and N Q Bit parallel data, perform parallel-to-serial conversion to get N S Bit recovery data.

[0055] In step 3-2B, when performing blind signal separation on the N+1 whitened signals, the complex mixing model is first converted into a real mixing model to eliminate the influence of phase ambiguity.

[0056] The present invention has the following beneficial effects:

[0057] 1. The present invention can achieve the purpose of simultaneously improving the system transmission capacity and interference tolerance by organically combining parallel combined spread spectrum at the transmitting end (to achieve waveform improvement) with blind signal separation at the receiving end.

[0058] 2. At the transmitting end, the data carrying capacity is expanded through the pseudo code combination relationship of parallel combination spread spectrum and the I and Q two-way orthogonal transmission mode.

[0059] 3. At the receiving end, blind signal separation can be used to further improve the interference tolerance of the spread spectrum system without increasing additional spectrum overhead. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The schematic diagram shows the principle of the parallel combination spread spectrum at the transmitting end in the present invention.

[0061] Figure 2 The schematic diagram shows the principle of blind signal separation at the receiving end in the present invention.

[0062] Figure 3 A simulation comparison diagram of the anti-interference capability of the present invention and the traditional non-coherent spread spectrum measurement and control communication system is shown. DETAILED DESCRIPTION

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0064] like Figure 1 and Figure 2 As shown, a method for expanding anti-interference measurement and control communication includes the following steps.

[0065] Step 1: Generate M candidate spreading sequences for use at the transmitter and receiver of the measurement and control link.

[0066] The above M candidate spreading sequences must have good autocorrelation and cross-correlation characteristics, and are PN1, PN2, ...PN M .

[0067] Step 2: Parallel combination spread spectrum at the transmitting end, such as Figure 1 As shown, the following steps are included.

[0068] Step 2-1, Parallel transmission: At the transmitter, send data N S Perform serial-to-parallel conversion to form I and Q bit parallel transmission, which are N I Bit parallel and N Q Bit parallel, then:

[0069]

[0070] Where, represents the possibility of selecting r pseudocodes from M pseudocodes for combination, Indicates rounding down.

[0071] It represents the possibility of selecting r pseudocodes from M-1 pseudocodes for combination.

[0072] Step 2-2: Spread spectrum and superposition

[0073] In I and Q, any candidate spreading sequence in any one channel is selected as the synchronization sequence, and all remaining candidate spreading sequences are spread.

[0074] In this example, select PN in I channel. M As a synchronization sequence. At this time, the synchronization sequence PN M It can be used as a synchronization signal between the transmitter and receiver, and can also be used as a correlation sequence for extracting the anti-interference signal and recovering the polarity after blind interference separation at the receiving end. As an alternative, any alternative spreading sequence in the Q channel can be selected, such as PN MAs a synchronization sequence, etc.

[0075] A、N I The method of bit parallel combination spreading and superposition preferably includes the following steps.

[0076] Step 2-2A1: Divide I-channel data into r bits and Two segments of bits.

[0077] Step 2-2A2, The communication data corresponding to the bit segment is PN1PN2…PN M-1 Data-spreading sequence mapping is performed to obtain r spreading sequences.

[0078] Step 2-2A3: Determine the polarities of the r spreading sequences according to the communication data corresponding to the r bit segments.

[0079] Step 2-2A4: Superimpose the selected r spreading sequences with polarity and the synchronization sequence PN M , get the I-way combined sequence signal d at time t I (t), the expression is:

[0080]

[0081] Where q j is the polarity of the j-th spreading sequence in channel I, which takes the value of +1 or -1; where 1≤j≤r.

[0082] PN j (t) is the jth spreading sequence in channel I at time t.

[0083] B. The above N Q The method of bit parallel combination spreading and superposition preferably includes the following steps.

[0084] Step 2-2B1: Divide Q-channel data into r bits and Two segments of bits.

[0085] Step 2-2B2, The communication data corresponding to the bit segment is PN1PN2…PN M Data-spreading sequence mapping is performed to obtain r spreading sequences.

[0086] Step 2-2B3: Determine the polarities of the r spreading sequences according to the communication data corresponding to the r bit segments.

[0087] Step 2-2B4: Superimpose the selected r spread spectrum sequences with polarity to obtain the Q-channel combined sequence signal d at time t. Q (t), the expression is:

[0088]

[0089] Where q i is the polarity of the i-th spreading sequence in the Q channel, which takes the value of +1 or -1; where 1≤i≤r.

[0090] PN i (t) is the i-th spreading sequence in the Q channel at time t.

[0091] Step 2-3, Carrier modulation: Carrier modulate the I and Q combined sequence signals to form an expanded anti-interference measurement and control waveform signal s(t), which is expressed as:

[0092]

[0093] Where, d I (t) is the I-channel combined sequence signal at time t.

[0094] d Q (t) is the Q-path combined sequence signal at time t.

[0095] f c is the carrier frequency, a known value; is the carrier phase, a known value.

[0096] Step 3, blind signal separation at the receiving end, preferably includes the following steps.

[0097] Step 3-1, Carrier demodulation: At the receiving end, the M R Each antenna demodulates the N interference signals and measurement and control signals received by each antenna to obtain M R Road observation signal.

[0098] The satellite-to-ground data transmission channel can be approximately modeled as an additive white Gaussian noise channel. In the process of transmission of the measurement and control signal through the channel, in addition to being affected by noise, it may also be subject to various intentional or unintentional interferences. Assume that the number of interference sources is N. Figure 2 As shown, at the receiving end of the measurement and control communication system, an array antenna is used to receive signals. Assume that the array antenna is a uniform linear array with M array elements. R Let θ S and θ v (v=1,2,...,N) represents the expansion anti-interference measurement and control signal and the elevation angle of each interference wave direction, then the array direction vector of the signal and interference is

[0099]

[0100] in:

[0101]

[0102] Where λ and f represent the signal wavelength and frequency respectively, c = 3 × 10 8 m / s, which represents the propagation speed of the incident wave.

[0103] a(θ S ) represents the array direction vector of the expanded anti-interference measurement and control signal.

[0104] a(θ v ) represents the array direction vector of the vth interference, and 1≤v≤N.

[0105] Let P S,r and P v,r (v=1,2,...,N) represents the extended anti-interference measurement and control signal at the front end of the receiving antenna and the vth interference power, respectively. v (t)(v=1,2,...,N) represents the interference of each channel, and the signal received by each element antenna of the linear array can be expressed as:

[0106]

[0107] Where, Represent the 1st, 2nd, ..., Mth R The observation signal of the antenna.

[0108] Represent the 1st, 2nd, ..., Mth R The noise vector of the antennas.

[0109] The received signal is demodulated by the carrier and then M is obtained. R The roadbed observation signal can be written into matrix form as follows:

[0110] x(t)=AS(t)+n(t)

[0111] in:

[0112]

[0113] A=[a(θ S )a(θ1)…a(θ N )]

[0114]

[0115] Where x(t), A, S(t), and n(t) represent the observed signal vector, mixing matrix, source signal vector, and noise vector, respectively.

[0116] The ratio of signal to interference power is When the interference intensity is large, making the signal-to-interference ratio greater than the system interference tolerance, it will be impossible to perform normal demodulation of the measurement and control signal based solely on the signal received by the array antenna.

[0117] Step 3-2: Blind signal separation

[0118] The expanded anti-interference measurement and control signal and the interference come from different physical sources, transmit different information, and meet statistical independence. Therefore, the interference-containing expanded anti-interference measurement and control signal can be processed by blind interference signal separation to obtain a relatively pure measurement and control signal.

[0119] The above-mentioned blind signal separation preferably includes the following steps.

[0120] Step 3-2A, whitening pre-processing: M R The N+1 whitened signals are obtained by whitening preprocessing.

[0121] like Figure 2 As shown, M R The observation signals are first pre-processed by whitening to obtain N+1 whitened signals. Let V represent the whitening matrix, then the whitened signal z=Vx satisfies E{zz H The specific method of whitening is:

[0122] Perform eigenvalue decomposition on the correlation matrix of x:

[0123] R x =E{xx H}=UΣU H

[0124] By E{zz H}=VE{xx H}V H =I, we can see that the whitening matrix can be taken as

[0125]

[0126] Where, Λ s is a diagonal matrix consisting of non-zero eigenvalues in Σ, U s It is an eigenvector matrix consisting of the eigenvectors corresponding to the non-zero eigenvalues in U.

[0127] Step 3-2B, Blind Signal Separation

[0128] The core of blind signal-to-noise separation is to guide the iteration of the separation matrix W by solving the objective function h[W], so that the result y of its interaction with the whitened signal z is an approximation of the source signal S.

[0129] Since the baseband signal to be processed is a complex-valued signal, the separated source signal has phase ambiguity, which will affect the subsequent polarity recovery of the r-bit data of the I and Q channels. Therefore, the independence of the I and Q channel data of the expanded anti-interference measurement and control signal is fully utilized to convert the complex mixing model into a real mixing model to eliminate the influence of phase ambiguity. Taking one-channel interference (N=1) as an example, the two complex mixed signals after whitening can be converted into four real mixed signals, which are composed of the four independent real and imaginary parts of the two complex source signals. That is, the complex form of the mixed signal is:

[0130]

[0131] Convert it into real number form, which is:

[0132]

[0133] In the above formula, the subscripts r and i represent the real and imaginary parts of each variable respectively. The normalized EASI algorithm is used to estimate the separation matrix W for the above real mixed signal uk , called the unconstrained separating matrix, and let

[0134]

[0135] In the above formula, w uij ,i,j=1,2,3,4 represents the unconstrained separation matrix W uk The separation rule of the normalized EASI algorithm is

[0136]

[0137] Where g(·) is a nonlinear function related to the statistical characteristics of the source signal, y k =W uk (k)x(k) is the separated signal. The correctly separated k-th moment signal y k =W uk (k)x(k) should have the following form:

[0138]

[0139] In order to correctly combine the separated real signals to form the complex source signal to be estimated, the separation matrix W uk Perform the following constraints to obtain the constraint separation matrix W k :

[0140]

[0141] When N>1, the N+1 complex mixed signals after whitening are converted into 2(N+1) real mixed signals, which are composed of 2(N+1) independent real and imaginary parts of N+1 complex source signals. The normalized EASI algorithm is used to obtain a 2(N+1)×2(N+1) dimensional unconstrained separation matrix W each time it is iterated. uk , and then through the above constraint relationship, we get the constraint separation matrix W k , thus ensuring y k =W k The real signals separated by x(k) are correctly combined together, while the phase ambiguity of the separated complex signals is removed.

[0142] Step 3-3, obtain the expansion anti-interference measurement and control signal: extract the I-channel data of each separated signal and compare it with the synchronization sequence PN M Do the correlation operation, get the estimated expansion anti-interference measurement and control signal through the maximum value judgment and polarity recovery, and use To express.

[0143] Step 3-4, recovery: First, extract the I and Q channel data from the expanded anti-interference measurement and control signal, and restore the I and Q channel bits in parallel, and then perform serial-to-parallel conversion to form recovered data.

[0144] In step 3-4, recovery preferably includes the following steps.

[0145] Step 3-4A: Extract I and Q channel data from the expanded anti-interference measurement and control signal respectively.

[0146] Step 3-4B, I-channel recovery: Compare I-channel data with PN1, PN2, ... PN M-1 Perform correlation operations respectively, and obtain the recovered N through maximum value judgment, polarity recovery and data-sequence inverse mapping. I Bit-parallel data.

[0147] Extract the estimated I branch data of the expanded anti-interference signal and Q branch data Despreading and data-sequence inverse mapping operations are performed respectively. Specifically, The same M-1 spreading sequences as the transmitting end are correlated separately, and the output signal of any correlator can be expressed as

[0148]

[0149] Among them, n i (t) is the output noise signal after the correlator. The maximum value of the correlation operation result is judged, r spread spectrum sequences are selected, and then the data-sequence inverse mapper is used to obtain bit data, combined with polarity information q I,i Get r bits of data, the two together constitute Bit-parallel recovery of data.

[0150] Step 3-4C, Q-channel recovery: Compare Q-channel data with PN1, PN2, ... PN M Perform correlation operations respectively, and obtain the restored N through maximum value judgment and polarity recovery. Q Bit-parallel data.

[0151] Will The M spreading sequences that are the same as those at the transmitting end are correlated separately, and the output signal of any correlator can be expressed as

[0152]

[0153] The maximum value of the result of the correlation operation is judged, r spreading sequences are selected, and then the data-sequence inverse mapper is used to obtain bit data, combined with polarity information q Q,i Get r bits of data, the two together constitute Bit-parallel recovery of data.

[0154] Step 3-4D, change N I bit-parallel data and N Q The bit-parallel data is merged and recorded as:

[0155]

[0156] Next, perform parallel-to-serial conversion to obtain the N S Bit recovery data.

[0157] The anti-interference capability of the capacity expansion anti-interference measurement and control communication method proposed in this invention is compared with that of the traditional non-coherent spread spectrum measurement and control communication system. Figure 3 As shown in the figure, the horizontal axis is the ratio of signal to interference power SJR, the vertical axis is the bit error rate BER, the interference type is broadband interference, and the interference bandwidth is half of the signal bandwidth. The two schemes use the same type of spreading code, the spreading code length is 32, that is, the spreading gain is 15dB, M is 32, and r is 2. Figure 3 It can be seen from the figure that when the interference intensity is large and exceeds the system interference tolerance, the bit error performance of the traditional incoherent spread spectrum measurement and control communication system drops sharply, while the bit error performance of the expanded anti-interference measurement and control communication method proposed in the present invention hardly changes with SJR. This is mainly because even when the SJR is low, the blind interference signal separation can still achieve a good signal-interference separation effect, thereby improving the system interference tolerance.

[0158] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the scope of protection of the present invention.

Claims

1. A capacity expansion and anti-interference measurement and control communication method, characterized by: The steps include: Step 1: Generate M candidate spreading sequences for use at the transmitter and receiver of the measurement and control link; Step 2: Parallel combination spread spectrum at the transmitting end, including: Step 2-1, Parallel Transmission: At the transmitter, the transmitted data is serial-to-parallel converted to form two parallel bit transmission paths, I and Q. Step 2-2, Spreading and Superposition: Any candidate spreading sequence in either I or Q path is selected as the synchronization sequence, and all remaining candidate spreading sequences are spread. Next, the spread sequences of the I and Q paths are combined and superimposed to form combined sequence signals of the I and Q paths. The synchronization sequence participates in the sequence superposition of the corresponding path. Step 2-3, carrier modulation: Carrier modulate the I and Q two-way combined sequence signals to form an expanded anti-interference measurement and control waveform signal; Step 3, blind signal separation at the receiving end: At the receiving end, all interference signals and measurement and control signals received by the array antenna are first carrier-demodulated, and then the observation signal after carrier demodulation is blindly separated from the interference signal to obtain the separated expanded anti-interference measurement and control signal; finally, the expanded anti-interference measurement and control signal is restored to obtain the recovered data.

2. The capacity expansion and anti-interference measurement and control communication method according to claim 1, characterized in that: In step 1, the generated M candidate spreading sequences have autocorrelation and cross-correlation characteristics, which are PN1, PN2, ... PN M .

3. The capacity expansion and anti-interference measurement and control communication method according to claim 2, characterized in that: In step 2-2, suppose PN in the selected I channel is M As a synchronization sequence, in step 2-1, the sent data is set to N S , I and Q bits are parallel and N I Bit parallel and N Q Bit parallel; then: Where, represents the possibility of selecting r pseudocodes from M pseudocodes for combination, Indicates rounding down; It represents the possibility of selecting r pseudocodes from M-1 pseudocodes for combination.

4. The capacity expansion and anti-interference measurement and control communication method according to claim 3, characterized in that: In step 2-2, N I The method of bit parallel combination spread spectrum and superposition includes: Step 2-2A1: Divide I-channel data into r bits and Two segments of bits; Step 2-2A2, The communication data corresponding to the bit segment is PN1PN2…PN M-1 Data-spreading sequence mapping to obtain r spreading sequences; Step 2-2A3: determining polarities of r spreading sequences according to the communication data corresponding to the r bit segments; Step 2-2A4: Superimpose the selected r spreading sequences with polarity and the synchronization sequence PN M , get the I-way combined sequence signal d at time t I (t), the expression is: Where q j is the polarity of the jth spreading sequence in channel I, which takes the value of +1 or -1; where 1≤j≤r; PN j (t) is the jth spreading sequence in channel I at time t.

5. The capacity expansion and anti-interference measurement and control communication method according to claim 3, characterized in that: In step 2-2, N Q The method of bit parallel combination spread spectrum and superposition includes: Step 2-2B1: Divide Q-channel data into r bits and Two segments of bits; Step 2-2B2, The communication data corresponding to the bit segment is PN1PN2…PN M Data-spreading sequence mapping to obtain r spreading sequences; Step 2-2B3: determining polarities of r spreading sequences according to the communication data corresponding to the r bit segments; Step 2-2B4: Superimpose the selected r spread spectrum sequences with polarity to obtain the Q-channel combined sequence signal d at time t. Q (t), the expression is: Where q i is the polarity of the i-th spreading sequence in the Q channel, which takes the value of +1 or -1; where 1≤i≤r; PN i (t) is the i-th spreading sequence in the Q channel at time t.

6. The capacity expansion and anti-interference measurement and control communication method according to claim 1, characterized in that: In step 2-3, the expression of the expanded anti-interference measurement and control waveform signal s(t) is: Where, d I (t) is the I-channel combined sequence signal at time t; d Q (t) is the Q-path combined sequence signal at time t; f c is the carrier frequency, a known value; is the carrier phase, a known value.

7. The capacity expansion and anti-interference measurement and control communication method according to claim 3, characterized in that: In step 3, the receiving end performs blind signal separation, including: Step 3-1, Carrier demodulation: At the receiving end, the M R Each antenna demodulates the N interference signals and measurement and control signals received by each antenna to obtain M R Road observation signal; Step 3-2, Blind signal separation: M R Blind signal separation is performed on the observation signal to obtain N+1 separated signals; Step 3-3, obtain the expansion anti-interference measurement and control signal: extract the I-channel data of each separated signal and compare it with the synchronization sequence PN M Do the correlation operation, get the estimated expansion anti-interference measurement and control signal through the maximum value judgment and polarity recovery, and use Step 3-4, recovery: first extract the I and Q path data from the expanded anti-interference measurement and control signal, and restore the I and Q path bits in parallel, and then perform serial-to-parallel conversion to form recovered data.

8. The capacity expansion and anti-interference measurement and control communication method according to claim 7, characterized in that: In step 3-2, blind signal and interference separation includes: Step 3-2A, whitening pre-processing: M R The N+1 whitened signals are obtained by whitening preprocessing the N+1 observation signals. Step 3-2B, blind signal-jamming separation: perform blind signal-jamming separation on the N+1 whitened signals so that the separated signal y is similar to the source signal S.

9. The capacity expansion and anti-interference measurement and control communication method according to claim 7, characterized in that: In steps 3-4, recovery includes the following steps: Step 3-4A: extract I and Q channel data respectively from the expanded anti-interference measurement and control signal; Step 3-4B, I-channel recovery: Compare I-channel data with PN1, PN2, ... PN M-1 Perform correlation operations respectively, and obtain the recovered N through maximum value judgment, polarity recovery and data-sequence inverse mapping operations. I bit-parallel data; Step 3-4C, Q-channel recovery: Compare Q-channel data with PN1, PN2, ... PN M Perform correlation operations, and obtain the recovered N through maximum value judgment, polarity recovery and data-sequence inverse mapping operations. Q bit-parallel data; Step 3-4D, change N I bit-parallel data and N Q Bit parallel data, perform parallel-to-serial conversion to get N S Bit recovery data.

10. The capacity expansion and anti-interference measurement and control communication method according to claim 8, characterized in that: In step 3-2B, when performing blind signal separation on the N+1 whitened signals, the complex mixing model is first converted into a real mixing model to eliminate the influence of phase ambiguity.

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