Chaos shift keying modulation and demodulation method based on time diversity and full-carrier label index difference and modem

Abstract

The invention relates to a chaos shift keying modulation and demodulation method based on time diversity and full-carrier label index difference, the method is suitable for various channels, especially suitable for power line transmission channels, and the method is mainly summarized as follows: a modulator transmits reference information or modulation information for multiple times at different moments by adopting a time diversity technology, and the time diversity technology is used as a reference signal; information carriers except a reference carrier are divided into two types of carriers which are activated in sequence by using index bits, and binary bits are distinguished by transmitting different modulation signals at odd and even moments. A demodulator averages signals at different moments on a reference carrier to obtain a reference signal and averages odd and even moments of an information carrier to obtain signals transmitted at the odd and even moments of each carrier, and each information carrier firstly distinguishes a first activated carrier and a second activated carrier according to different signals transmitted at the odd and even moments so as to recover mapping bits; and then corresponding modulation bits are respectively demodulated on the first activation carrier and the second activation carrier. According to the invention, the anti-noise performance and the transmission rate of the system are improved.

Description

Technical Field

[0001] The present invention relates to the fields of power line communication technology and wireless communication technology, and in particular to a time diversity and full carrier index differential chaotic shift keying modulation and demodulation method and a modem, which are particularly suitable for data transmission over power line channels. Background Art

[0002] Differential Chaotic Shift Keying (DCSK) is a non-coherent chaotic digital communication modulation method that uses a chaotic signal as a carrier and has a low implementation complexity. The communication scheme based on DCSK can effectively resist various background noises and pulse noises in the power line channel and is an excellent alternative for power line communication.

[0003] Power-line communication (PLC) is a key technology for building smart grids. It does not require the laying of additional communication links, but uses existing low-voltage power lines to transmit information.

[0004] Patent document CN116405360A discloses a high data rate carrier index differential chaotic keying modulation and demodulation method and system based on a scrambled matrix. The method of repeated circuit and average processing can greatly reduce the noise component in the decision variable and improve the system's bit error performance. However, since the patent only selects one carrier from multiple carriers according to the index bit to transmit the DCSK modulation symbol, and the remaining carriers do not transmit any information, the transmission rate and energy efficiency of the system are extremely low. The present invention will utilize the repeated transmission of the reference signal and the conversion signal of the reference signal on each carrier, not only using the index bit to select the activated carrier to transmit the DCSK modulation symbol, but also using the inactive carrier to transmit the modulation symbol, which will greatly improve the transmission rate and energy efficiency of the system. Summary of the invention

[0005] Aiming at the background noise, pulse noise and multipath fading existing in the power line communication channel, the present invention provides a modulation and demodulation method and a modem based on time diversity and full carrier label index differential chaotic shift keying. In order to resist various noises in the power line channel, the modulator adopts time diversity to transmit reference information or modulation information multiple times at different times, and combines the information transmitted in different time slots at the receiving end in an equal gain manner.

[0006] The technical solution of the present invention is as follows:

[0007] On the one hand, the present invention provides a time diversity and full-carrier index differential chaotic shift keying modulation and demodulation method, which is characterized in that: at the transmitting end: using time diversity technology, using different time to transmit reference information or modulation information multiple times, each frame of the chip length C is determined by 2g consecutive time and each time chip length L, C = 2g * L; using m + 1 carriers to transmit information simultaneously, wherein the first carrier is used to transmit reference information s1, and repeatedly transmit the same chip group {r1, r2, r3, ..., r4, ..., r5, ..., r6, ..., r7, ..., r8, ..., r9, ..., r10, ..., r11, ..., r12, ..., r13, ..., r14, ..., r15, ..., r16, ..., r17, ..., r18, ..., r19, ..., r20, ..., r21, ..., r22, ..., r23, ..., r24, ..., r25, ..., r26, ..., r27, ..., r28, ..., r29, ..., r30, ..., r31, ..., r32, ..., r33, ..., r34, ..., r35, ..., r36, ..., r37, ..., r38, ..., r39, ..., r39, ..., r39, ..., r39, ..., r39, ..., r40, ..., r41, ..., r42, ..., r43, ..., r44, ..., r45, ..., r46, ..., r47, ..., r48, ..., r49, ..., r59, ..., r60, ..., r61, ..., r61, ..., r61, ..., r71, ..., r72, ..., r73, ..., r74, ..., r8 L The remaining carriers 2 to m+1 are used to transmit modulation information, and carrier index modulation is introduced, including the steps of:

[0008] c. Group the input bit sequence into groups, each group containing q bits, wherein the first q1 bits are mapping bit groups, which are used to select q2 first activated carriers and m-q2 later activated carriers from carriers No. 2 to m+1; the last q-q1 bits are modulation bit groups, which are composed of a first modulation bit group and a second modulation bit group;

[0009] d. First, activate the carrier to transmit the pre-modulation bit group at 2g consecutive moments, and use the reference chaotic signal to represent the modulation bit 1 or 0. That is, when the transmitted modulation bit is 1, s is transmitted at 2g consecutive moments. f ={r1,r2,r3,......,r L}, when the transmitted modulation bit is 0, s is transmitted at 2g consecutive moments f ={-r1,-r2,-r3,......,-r L};

[0010] e. The post-activation carrier transmits different chip groups at odd and even times to represent the modulation bit 1 or 0, that is, when the modulation bit transmitted is 1, the odd time transmits s so ={r1,r2,r3,......,r L}, transmit at even times

[0011] s se ={-r1,-r2,-r3,......,-r L}, when the modulation bit is 0, odd-numbered times transmit s so ={-r1,-r2,-r3,......,-r L}, transmit s at even times se ={r1,r2,r3,......,r L};

[0012] At the receiving end: the m+1 carrier is received by a matched filter and processed in the order of frames, including the steps:

[0013] a. In each chip period T c Sampling is not performed, that is, 2gL code chip sampling values ​​are obtained from each carrier branch, and the sampling values ​​of the reference information on carrier No. 1 are stored in vector R 1×2gL The sampled values ​​of the modulation information of carriers 2 to m+1 are stored in the matrix I m×2gL middle;

[0014] b. Perform time gain processing and group averaging on the received signal;

[0015] c. Determine the first activated carrier and the second activated carrier through correlation operation, and restore the mapping bit by combining the number of the first activated carrier;

[0016] d. Determine the modulation bit according to the sign of the correlation result;

[0017] e. Arrange the bits carried by the first activated carrier in the order of the carrier number to form a first modulation bit sequence; arrange the bits carried by the second activated carrier in the order of the carrier number to form a second modulation bit sequence; arrange the first modulation bit sequence and the second modulation bit sequence to obtain a modulation bit sequence, and arrange the mapped bits and the modulation bits to obtain the original bit sequence.

[0018] Further, the step b. performs time gain processing and grouping averaging on the received signal, specifically:

[0019] - vector R 1×2gL The data is divided into a group for every L columns, and 2g groups are obtained for each row. The L sample values ​​are averaged according to the order of arrangement of each group of data and stored in vector N. 1×L middle;

[0020] - The matrix I m×2gL The data in the matrix is ​​grouped every L rows, and 2g groups are obtained for each row. The L sample values ​​of the odd-numbered array are averaged according to the order of arrangement within the group and stored in the matrix O. m×L In the even-numbered array, the L sample values ​​are averaged according to the order of arrangement within the group and stored in the matrix E. m×L middle;

[0021] Further, the step c. determines the first activated carrier and the second activated carrier by correlation operation, and restores the mapping bit by combination method according to the number of the first activated carrier, specifically:

[0022] - vector N 1×L Respectively with the matrix O m×L And the matrix E m×L are related and stored in the matrix CO m×1 and Matrix CE m×1 middle;

[0023] - Matrix CO m×1 and Matrix CE m×1 Add together to get the correlation matrix C m×1 ;

[0024] - Correlation matrix C m×1 The absolute value is calculated to obtain the q2 carriers with the largest absolute value, that is, the carrier is activated first, and the mapping bits are restored by the combination method according to its carrier number;

[0025] -The remaining m-q2 carriers with small absolute values ​​are the later activated carriers.

[0026] Further, the step d. is based on the sign of the correlation result, that is, the correlation matrix C m×1 The symbol determines the modulation bit, specifically:

[0027] The sign of the carrier number row corresponding to the first activated carrier determines the bit transmitted by the first activated carrier. If the sign is positive, it is judged as "1", and if the sign is negative, it is judged as "0";

[0028] The sign of the carrier number row corresponding to the post-activated carrier determines the bit transmitted by the post-activated carrier. If the sign is positive, it is judged as "0", and if the sign is negative, it is judged as "1".

[0029] On the other hand, the present invention also provides a time diversity and full carrier index differential chaotic shift keying modem, comprising a modulator and a demodulator, wherein the modulator modulates the input signal according to the method described in the transmitting end, and the demodulator demodulates the received signal according to the method described in the receiving end.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) Through time diversity, that is, using 2g consecutive transmissions of the same chaotic signal at different times, the negative impact of background noise and pulse noise in the power line channel can be effectively improved, and the system's bit error rate performance and data transmission rate can be improved.

[0032] 2) The present invention not only utilizes the selection of carrier numbers to transmit mapping bits, but also utilizes the carrier number index modulation to select the first activated carrier to transmit the first modulation bits, and also utilizes the later activated carrier to transmit the later modulation bits.

[0033] 3) In order to distinguish the first activated carrier and the later activated carrier at the receiving end, the present invention transmits information by transmitting different code chips at odd and even times on the two types of carriers. The present invention transmits more information bits than the existing DCSK system and improves energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1The structure of the transmission signal frame transmitted on the carrier waves is shown;

[0035] Figure 2 The structure of the DCSK modulator based on full carrier index modulation is shown;

[0036] Figure 3 The structure of the DCSK demodulator based on full carrier index modulation is shown; DETAILED DESCRIPTION

[0037] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0038] During modulation, the duration of L chips is regarded as a transmission at one time. To ensure the effectiveness of diversity, 2g consecutive different times are used to transmit the same reference information or modulation information, so the chip length of each frame is C = 2g*L. The modulator uses m+1 carriers to transmit each frame of information at the same time, and numbers the carriers from 1 to m+1. The first carrier transmits the reference information, so the signal s1 transmitted by the first carrier will transmit the chip group {r1, r2, r3, ..., r L}, and then the code chips are waveform shaped. The remaining carriers numbered from 2 to m+1 will transmit information. In order to transmit more bits and improve the performance of the system, carrier label index modulation will be introduced. The detailed process is as follows. In the first step, the input bit sequence will be grouped first, and then the bits of each group will be transmitted in one frame. Each group contains q bits, of which the first q1 bits are mapping bit groups, and the last q-q1 bits are modulation bit groups. The modulation bit groups are divided into two groups, namely the pre-modulation bit group and the post-modulation bit group. In the second step, each group of bit sequences will generate a transmission signal according to the following steps. First, the combination method is used to select q2 first-activated carriers from the carriers numbered from 2 to m+1 according to the mapping bits to transmit the pre-modulation bit group. The remaining m-q2 carriers are called post-activated carriers, and the post-activated carriers will be used to transmit the post-modulation bit group. In order to enable the receiving end to distinguish the q2 first-activated carriers from the m-q2 post-activated carriers, the first-activated carriers will use the reference chaotic signal (denoted as r={r1,r2,r3,......,r L}) Transmit the pre-modulation bit group. When the transmitted modulation bit is 1, transmit s at 2g consecutive moments. f ={r1,r2,r3,......,r L}, when the transmitted modulation bit is 0, s is transmitted at 2g consecutive moments f ={-r1,-r2,-r3,......,-r L}. The carrier will be activated later and different chip groups will be transmitted at odd and even times. When the modulated bit transmitted is 1, the odd time transmits s so ={r1,r2,r3,......,r L}, transmit s at even times se ={-r1,-r2,-r3,......,-r L}, when the modulation bit is 0, odd-numbered times transmit s so ={-r1,-r2,-r3,......,-r L}, transmit s at even times se ={r1,r2,r3,......,r L}.

[0039] The corresponding demodulation method at the receiving end is as follows. The m+1 carriers will be received using matched filters and processed in sequence according to the order of the frames. The sampled values ​​of the reference information transmitted on carrier 1 will be stored in vector R 1×2gL The remaining carrier samples numbered 2 to m+1 will be stored in the matrix I m×2gL In order to obtain time gain, R 1×2gL The data in is grouped every L columns to get 2g groups, and then the L sample values ​​are averaged according to the order of each group of data to get the vector N 1×L . Will I m×2gL The data is grouped into L groups per row, and 2g groups are obtained for each row. The L sample values ​​of the odd-numbered group are averaged according to the order of arrangement within the group and stored in O m×L In the even-numbered group, the L sample values ​​are averaged according to the order of arrangement within the group and stored in E m×L In. 1×L Respectively with O m×L and E m×L Related and stored separately in CO m×1 and CE m×1 In. CO m×1 and CE m×1 Adding them together will give C m×1 . m×1 The q2 carriers with the largest absolute values ​​are activated first, and the mapping bits are restored using the combination method according to their carrier numbers. The remaining m-q2 carriers with small absolute values ​​are activated later. m×1The sign of the carrier number row corresponding to the first activated carrier determines the information bit transmitted by the first activated carrier. If the sign is positive, it is judged as "1", and if the sign is negative, it is judged as "0". The sign of the carrier number row corresponding to the later activated carrier determines the bit transmitted by the later activated carrier. If the sign is positive, it is judged as "0", and if the sign is negative, it is judged as "1". The bits carried by the first activated carrier are arranged in the order of carrier numbers to obtain the first modulation bit sequence, and the bits carried by the later activated carrier are arranged in the order of carrier numbers to obtain the later modulation bit sequence. Arrange the first and last modulation bits to obtain the modulation bit sequence. Arrange the mapping bits and the modulation bits to obtain the bit sequence of each frame.

[0040] Example:

[0041] Figure 2 The figure shows the structure of the DCSK modulator based on time diversity and full carrier index modulation for power line channels. Each frame of the bit sequence transmitted by the system includes a carrier index modulation mapping bit sequence and a DCSK modulation bit sequence. The bit sequence of each frame is expressed as The bit sequence Mapping bit stream to carrier label, bit sequence and The total number of carriers is m+1, and the carrier frequencies corresponding to them are f1 to f1, respectively. m+1 , where the reference information is transmitted using a carrier with a carrier frequency of f1. Select q2 carriers from m carriers as the first activated carriers and m-q2 carriers as the second activated carriers. and The polarity converter maps the modulated information symbol to a DCSK modulation symbol, that is, the modulation bit "0" or "1" will be mapped to the DCSK modulation information symbol "1" or "-1" respectively.

[0042] The specific modulation process of the modulator is as follows: the chaotic signal generator R generates a chaotic signal with a length of L The time diversity device T uses 2g time points to generate four frame structures with a length of 2gL chips. Figure 1 As shown, first activate the carrier to use all transmission at 2g time or To distinguish "0" and "1". The post-activated carrier is transmitted at odd and even times respectively. or To distinguish "0" and "1". The reference carrier branch will select the frame with frame structure Z1 for transmission. The frames transmitted by the remaining m carriers will be determined by mapping bits and modulation bits, as shown below. The bit sequence s to be transmitted in each framei First, they are divided into 3 groups, the first q1 bits are mapping bits, the middle q2 bits are first modulation bits, and the last m-q2 bits are second modulation bits. The q1 mapping bits are indexed by the modulator to select q2 carriers from the carriers numbered 2 to m as the first activated carriers and record the carrier numbers in ascending order as N1 = {i1, i2, ..., i q2}where i1 represents the smallest number of the first activated carrier, i q2 Indicates that the largest number of carriers is activated first, and i1 to i q2 The remaining m-q2 carriers are activated later and are labeled in ascending order as N2 = {j1, j2, ..., j m-q2}, where j1 represents the smallest number among the later activated carriers, j m-q2 Represents the largest number among the later activated carriers and j1 to j m-q2 Belongs to [2,...,m+1]. The corresponding index modulator will generate a control signal for the output frequency of the oscillator corresponding to the carrier numbered 2 to m, so that the frequency is f t,1 to f t,q2 The activated carriers correspond to the carrier numbers i1, i2, ..., i q2 , frequency is f s,1 to f s,m-q2 The inactive carriers are numbered in the order of j1, j2, ..., j m-q2 . Superimposing m+1 signals will generate the information modulated signal s(t).

[0043] like Figure 3 The DCSK demodulator structure based on time diversity and full carrier index modulation is suitable for power line channels. The specific implementation process of the demodulator is as follows: the receiver divides the received signal g(t) into m+1 paths with equal power, and then uses the transmitter with the indexes f1 to f m+1 The carrier frequency is mixed with the signal after power division, and then matched filtering is performed. c The sampling is not performed, so that 2gL code chip sampling values ​​are obtained from each carrier branch. And the 2gL sampling values ​​of the reference chaotic signal corresponding to the carrier frequency f1 are stored in the matrix R 1×2gL The carrier frequency is f2 to f m+1 The sampling values ​​corresponding to each carrier are stored in the matrix I m×2gL middle.

[0044] To obtain time gain, R 1×2gL The data in is grouped every L columns to get 2g groups, and then the L sample values ​​are averaged according to the order of each group of data to get the matrix N 1×L . Will Im×2gL The data is grouped into L groups per row, and 2g groups are obtained per row. The L sample values ​​of the odd-numbered group are averaged according to the order of arrangement within the group and stored in the matrix O m×L In the even-numbered array, the L sample values ​​are averaged according to the order of arrangement within the group and stored in the matrix E. m×L In the matrix N 1×L Respectively with O m×L and E m×L Correlation and store the correlation values ​​in CO m×1 and CE m×1 In. The matrix CO m×1 and CE m×1 Adding together will give us the matrix C m×1 . m×1 The q2 carriers with the largest absolute values ​​are the first activated carriers, and the q1 mapping bits are restored according to their carrier labels using the index demodulator based on the combination method. The remaining m-q2 carriers with small absolute values ​​are the later activated carriers. m×1 The symbol of the carrier number row corresponding to the first activated carrier will determine the information bit transmitted by the first activated carrier under the control of the mapping bit. The symbol of the carrier number row corresponding to the first activated carrier will determine the bit transmitted by the first activated carrier. If the symbol is positive, it is judged as "1", and if the symbol is negative, it is judged as "0". The symbol of the carrier number row corresponding to the later activated carrier will determine the bit transmitted by the later activated carrier. If the symbol is positive, it is judged as "0", and if the symbol is negative, it is judged as "1". The bits carried by the first activated carrier are arranged in the order of carrier numbers to obtain the first modulation bit sequence, and the bits carried by the later activated carrier are arranged in the order of carrier numbers to obtain the later modulation bit sequence. Arrange the first and last modulation bits to obtain the modulation bit sequence. Arrange the mapping bits and the modulation bits to obtain the bit sequence of each frame.

[0045] The test shows that the present invention adopts time diversity technology to enhance the anti-interference ability of the signal by transmitting the same information multiple times at different time points. This is particularly important in environments with more noise, such as power line channels. The carrier number classification modulation is adopted, and the carrier number index modulation is introduced, which not only increases the transmission amount of information, but also improves the overall performance of the system. This method allows the modulator to transmit additional information through different carriers, thereby more effectively utilizing the available frequency band resources. A complex encoding and decoding strategy is designed, including bit grouping, separation of mapping bits and modulation bits, and complex processing procedures at the receiving end, to ensure accurate transmission and efficient decoding of information. Therefore, the present invention fully considers the characteristics of the power line channel and improves the efficiency and stability of information transmission.

Claims

1. A method for modulation and demodulation based on time diversity and full carrier index differential chaotic shift keying, characterized in that: At the transmitting end: time diversity technology is used to transmit reference information or modulation information multiple times at different times. The chip length C of each frame is determined by 2g consecutive moments and the chip length L of each moment, C = 2g*L; m+1 carriers are used to transmit information simultaneously, where carrier No. 1 is used to transmit reference information s1, and the same chip group {r1, r2, r3, ..., r4, ..., r5, ..., r6, ..., r7, ..., r8, ..., r9, ..., r10, ..., r11, ..., r12, ..., r13, ..., r14, ..., r15, ..., r16, ..., r17, ..., r18, ..., r19, ..., r20, ..., r21, ..., r22, ..., r31, ..., r43, ..., r54, ..., r19, ..., r21, ..., r31, ..., r1 L The remaining carriers 2 to m+1 are used to transmit modulation information, and carrier number index modulation is introduced, including the steps of: a. Group the input bit sequence into groups, each group contains q bits, wherein the first q1 bits are mapping bit groups, which are used to select q2 first activated carriers and m-q2 later activated carriers from carriers 2 to m+1; the last q-q1 bits are modulation bit groups, which are composed of a front modulation bit group and a rear modulation bit group; b. First, activate the carrier to transmit the pre-modulation bit group at 2g consecutive moments, and use the reference chaotic signal to represent the modulation bit 1 or 0. That is, when the transmitted modulation bit is 1, s is transmitted at 2g consecutive moments. f ={r1,r2,r3,......,r L }, when the transmitted modulation bit is 0, s is transmitted at 2g consecutive moments f ={-r1,-r2,-r3,......,-r L }; c. The post-activation carrier transmits different chip groups at odd and even times to represent the modulation bit 1 or 0, that is, when the modulation bit transmitted is 1, the odd time transmits s so ={r1,r2,r3,......,r L }, transmit s at even times se ={-r1,-r2,-r3,......,-r L }, when the modulation bit is 0, odd-numbered times transmit s so ={-r1,-r2,-r3,......,-r L }, transmit s at even times se ={r1,r2,r3,......,r L }; At the receiving end: the m+1 carrier is received by a matched filter and processed in the order of frames, including the steps: a. In each chip period T c Sampling is not performed, that is, 2gL code chip sampling values ​​are obtained from each carrier branch, and the sampling values ​​of the reference information on carrier No. 1 are stored in vector R 1×2gL The sampled values ​​of the modulation information of carriers 2 to m+1 are stored in the matrix I m×2gL middle; b. Perform time gain processing and group averaging on the received signal; c. Determine the first activated carrier and the second activated carrier through correlation operation, and restore the mapping bit by combining the number of the first activated carrier; d. Determine the modulation bit according to the sign of the correlation result; e. Arrange the bits carried by the first activated carrier in the order of the carrier number to form a first modulation bit sequence; arrange the bits carried by the second activated carrier in the order of the carrier number to form a second modulation bit sequence; arrange the first modulation bit sequence and the second modulation bit sequence to obtain a modulation bit sequence, and arrange the mapped bits and the modulation bits to obtain the original bit sequence.

2. The method for modulation and demodulation based on time diversity and full carrier index differential chaotic shift keying according to claim 1 is characterized in that: The step b. performing time gain processing and grouping averaging on the received signal is specifically: - vector R 1×2gL The data is grouped every L columns, and each column gets 2g groups. The L sample values ​​are averaged according to the order of each group of data and stored in vector N. 1×L middle; - The matrix I m×2gL The data in the matrix is ​​grouped every L rows, and 2g groups are obtained for each row. The L sample values ​​of the odd-numbered array are averaged according to the order of arrangement within the group and stored in the matrix O. m×L In the even-numbered array, the L sample values ​​are averaged according to the order of arrangement within the group and stored in the matrix E. m×L middle; 3. The method for modulation and demodulation based on time diversity and full carrier label index differential chaotic shift keying according to claim 2 is characterized in that: The step c. determines the first activated carrier and the second activated carrier by correlation operation, and restores the mapping bit by combination method according to the number of the first activated carrier, specifically: - vector N 1×L Respectively with the matrix O m×L And the matrix E m×L are related and stored in the matrix CO m×1 and Matrix CE m×1 middle; - Matrix CO m×1 and Matrix CE m×1 Add together to get the correlation matrix C m×1 ; - Correlation matrix C m×1 The absolute value is calculated to obtain the q2 carriers with the largest absolute value, that is, the carrier is activated first, and the mapping bits are restored by the combination method according to its carrier number; -The remaining m-q2 carriers with small absolute values ​​are the later activated carriers.

4. The method for modulation and demodulation based on time diversity and full carrier index differential chaotic shift keying according to claim 1 is characterized in that: The step d. is based on the sign of the correlation result, that is, the correlation matrix C m×1 The symbol determines the modulation bit, specifically: The sign of the carrier number row corresponding to the first activated carrier determines the bit transmitted by the first activated carrier. If the sign is positive, it is judged as "1", and if the sign is negative, it is judged as "0"; The sign of the carrier number row corresponding to the post-activated carrier determines the bit transmitted by the post-activated carrier. If the sign is positive, it is judged as "0", and if the sign is negative, it is judged as "1".

5. A time diversity and full carrier index differential chaotic shift keying modem, comprising a modulator and a demodulator, characterized in that: The modulator modulates the input signal according to the method described in the transmitting end of claim 1 or 2.

6. A time diversity and full carrier index differential chaotic shift keying modem, comprising a modulator and a demodulator, characterized in that: The demodulator demodulates the received signal according to the method described in any one of claims 1-4.

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