An OFDM-IM transmission method using bit-interleaved coded modulation

Abstract

The application relates to an OFDM-IM transmission method adopting bit interlaced coding modulation and belongs to the technical field of wireless communication, solves the problems that frequency diversity gain cannot be obtained, transmission performance is weak, and it is difficult to realize high detection performance after channel coding is combined with OFDM-IM in the prior art. Through a data transmission method, input bit information is segmented and processed to obtain SAP information and constellation symbol information; based on the SAP information and the constellation symbol information, an OFDM-IM data block is obtained, and data transmission is carried out after processing; through a data receiving method, received information is processed; the processed received information is independently and in parallel detected to respectively obtain SAP soft information and constellation symbol soft information; a detection result of constellation information is obtained by using the SAP soft information, and a detection result of index information is obtained by using the constellation symbol soft information; the detection results are combined to obtain output bit information. Frequency diversity gain is obtained, and high detection performance is obtained after channel coding is combined with OFDM-IM.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to an OFDM-IM (Orthogonal Frequency Division Multiplexing with index modulation) transmission method employing bit-interleaved coding modulation. Background Technology

[0002] With the development of wireless communication technology, OFDM-IM (Orthogonal Frequency Division Multiplexing with Index Modulation) technology is being used more and more widely.

[0003] OFDM-IM technology divides the subcarriers of the entire data block into multiple groups, activating a portion of the subcarriers in each group to transmit symbol information in each time slot, while simultaneously using SAP (Subcarrier Activation Pattern) to carry additional information. In OFDM-IM, the energy of inactive subcarriers can be reconfigured to transmit information on active subcarriers, and the symbol information of active subcarriers can obtain a certain power gain. OFDM-IM can be considered a more flexible OFDM multicarrier transmission technology; OFDM can be seen as a special case of OFDM-IM that activates all subcarriers to transmit symbol information without utilizing SAP to carry additional information. Research has shown that pure OFDM does not capture the frequency diversity gain in multipath channels, therefore pure OFDM-IM also faces the problem of not being able to acquire frequency diversity gain and having weak transmission performance. Meanwhile, channel coding plays a crucial role in wireless communication and is an important means of improving transmission reliability; however, when channel coding is combined with OFDM-IM technology, designing an effective receiver structure to achieve better detection performance presents certain challenges.

[0004] In summary, current OFDM-IM technology suffers from several drawbacks, including the inability to obtain frequency diversity gain, weak transmission performance, and difficulty in achieving high detection performance by combining channel coding with OFDM-IM. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide an OFDM-IM transmission method using bit-interleaved coding modulation to solve the problems in the prior art, such as the inability to obtain frequency diversity gain, weak transmission performance, and difficulty in achieving high detection performance by combining channel coding with OFDM-IM.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] This invention provides an OFDM-IM transmission method employing bit-interleaved coding modulation, including a data transmission method and a data reception method; wherein,

[0008] The data transmission method includes: segmenting the input bit information to obtain index information and constellation diagram information; processing the index information and constellation diagram information to obtain SAP information and constellation diagram symbol information respectively; obtaining OFDM-IM data blocks based on the SAP information and constellation diagram symbol information, and transmitting the data after processing.

[0009] The data receiving method includes: processing the received information; performing independent parallel detection on the processed received information to obtain SAP soft information and constellation symbol soft information respectively; using the SAP soft information to obtain the detection result of constellation information, and using the constellation symbol soft information to obtain the detection result of index information; and merging the detection results of index information and constellation information to obtain output bit information.

[0010] Based on a further improvement of the above method, the index information is processed to obtain SAP information, including:

[0011] The index information is sequentially processed by convolutional coding with a code rate of r1 and bit interleaving Π1 coding to obtain index encoded information;

[0012] The SAP information is obtained by index modulation of the index-encoded information.

[0013] Based on a further improvement of the above method, the constellation diagram information is processed to obtain constellation diagram symbol information, including:

[0014] The constellation diagram information is sequentially processed by convolutional coding with a code rate of r2 and bit interleaving π2 coding to obtain constellation diagram encoded information;

[0015] The constellation diagram encoding information is subjected to constellation diagram modulation to obtain the constellation diagram symbol information.

[0016] A further improvement to the above method, the step of obtaining OFDM-IM data blocks based on SAP information and constellation diagram symbol information, includes:

[0017] Based on the SAP information, obtain the data arrangement matrix;

[0018] The OFDM-IM data block is obtained by multiplying the data arrangement matrix with the constellation diagram symbol information.

[0019] Based on a further improvement to the above method, the data transmission after processing includes:

[0020] The OFDM-IM data blocks are subjected to symbol interleaving Π3 processing to break down the symbol information of each group;

[0021] The shuffled symbol information is processed by IFFT (Inverse Fast Fourier Transform) and then emitted after adding a cyclic prefix.

[0022] Based on further improvements to the above method, the received information is processed, including:

[0023] The received information is sequentially processed by removing cyclic prefixes, performing FFT (Fast Fourier Transform) processing, and symbol deinterleaving. Process the data to obtain the processed received information.

[0024] Based on further improvements to the above method, the processed received information is independently and in parallel detected to obtain SAP soft information, including:

[0025] The processed received information is subjected to LLR (Log-Likelihood Ratio) calculation to obtain the LLR of SAP information;

[0026] Bit deinterleaving of SAP information LLR The SAP soft information is obtained through processing, SISO (Soft Input Soft Output) detection processing, and bit interleaving Π1 processing.

[0027] Based on a further improvement to the above method, the step of independently and in parallel detecting the processed received information to obtain constellation symbol soft information includes:

[0028] The received information after processing is subjected to LLR calculation to obtain the LLR of constellation diagram symbol information;

[0029] Bit deinterleaving of LLR constellation symbol information The constellation diagram symbol soft information is obtained through processing, SISO detection processing, and bit interleaving π2 processing.

[0030] Based on further improvements to the above method, the detection results of constellation map information obtained using the SAP soft information include:

[0031] The SAP soft information and constellation symbol soft information are cross-feeded back, and the SAP soft information is used to correct the LLR of the constellation symbol information, while independent parallel detection continues.

[0032] When the detection performance remains essentially unchanged, stop the iteration and obtain the detection results based on the constellation diagram information.

[0033] Based on a further improvement of the above method, the detection results of index information are obtained using the soft information of the constellation diagram symbols, including:

[0034] The SAP soft information and constellation symbol soft information are cross-feeded, and the constellation symbol soft information is used to correct the LLR of the SAP information, while independent parallel detection continues.

[0035] When the detection performance remains essentially unchanged, stop the iteration and obtain the detection results for the index information.

[0036] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0037] 1. This invention designs an OFDM-IM transmission method using bit interleaving coding modulation, which obtains frequency diversity gain through bit interleaving coding modulation technology, thereby improving the transmission performance of OFDM-IM.

[0038] 2. This invention designs an OFDM-IM transmission method using bit-interleaved coding modulation. By designing a parallel iterative feedback detection link in the system, it can effectively reduce the impact of SAP detection (or constellation symbol detection) errors on constellation symbol detection (or SAP detection) and improve detection performance.

[0039] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0040] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0041] Figure 1 Here is a block diagram of the transmitter.

[0042] Figure 2 Block diagram of the receiver;

[0043] Figure 3 The transmission BER (Bit Error Rate) of this invention under different channel orders L;

[0044] Figure 4This paper compares the performance of the proposed BICM (Bit-Interleaved Coded Modulation)-OFDM-IM with existing BICM-OFDM schemes. Detailed Implementation

[0045] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0046] Example 1

[0047] This invention provides an OFDM-IM transmission method using bit-interleaved coding modulation, including a data transmission method and a data reception method:

[0048] S1. Data transmission method, including:

[0049] The input bit information is segmented to obtain index information and constellation diagram information; the index information and constellation diagram information are processed to obtain SAP information and constellation diagram symbol information; based on the SAP information and constellation diagram symbol information, OFDM-IM data blocks are obtained, processed, and then data is transmitted.

[0050] S2. Data receiving method, including:

[0051] The received information is processed; the processed received information is detected independently and in parallel to obtain SAP soft information and constellation symbol soft information respectively; the detection results of constellation information are obtained using the SAP soft information, and the detection results of index information are obtained using the constellation symbol soft information; the detection results of index information and constellation information are merged to obtain output bit information.

[0052] Compared with existing technologies, the method provided in this embodiment combines OFDM-IM technology with bit interleaving coding modulation technology and designs a corresponding parallel feedback iterative detection method. It extends the detection from the symbol-level detection of existing SAP to the bit-level detection and decoding of SAP additional information, which can effectively obtain frequency diversity gain and improve the detection performance of SAP information and constellation diagram symbol information.

[0053] Example 2

[0054] Based on Example 1, step S1 can be further refined into the following steps:

[0055] S11. Set each OFDM data block in the system to contain N subcarriers, and each OFDM data block is divided into G groups, each group containing n subcarriers, i.e., N = Gn.

[0056] The channel is set as a multipath Rayleigh fading channel, the channel order is denoted as L, and the receiver knows the channel state information, while the transmitter does not know the channel state information.

[0057] Construct the transmitter, such as Figure 1 As shown, the transmitter takes the g-bit input information, performs bit segmentation processing, and obtains g1-bit index information and g2-bit constellation diagram information respectively.

[0058] S12. The index information of bit g1 is processed by convolutional coding at code rate r1 and bit interleaving Π1 to obtain index coding information. Then, through index modulation processing, i.e., according to the mapping rule between the index coding information and the selection of active subcarrier mode, k subcarriers are selected from n subcarriers, and the sequence number of the selected subcarriers is recorded (a subset of the set [1,…,n] containing k elements). Then, according to the rule that the selected sequence number is marked as 1 and the unselected one is marked as 0, SAP (Subcarrier Activation Pattern) information composed of 0 or 1 is obtained; wherein, preferably, the mapping rule can be set as follows: when (n,k)=(4,3), it is pre-defined that when the index coding information is 00, the active subcarrier sequence number is (2,3,4); when the index information is 01, the active subcarrier sequence number is (1,3,4), etc. The data arrangement matrix D is obtained based on the SAP information. This involves selecting the corresponding k columns from an n×n identity matrix to form an n×k dimensional matrix. For example, if the SAP information is

[0111] , the 2nd, 3rd, and 4th columns of a 4×4 identity matrix are selected to obtain a 4×3 matrix D.

[0059] The number of bits carried by the SAP message for the entire data block can be expressed as:

[0060]

[0061] in, This indicates rounding down to the nearest integer. Indicates the number of valid SAP messages. This represents the minimum Hamming distance between valid SAP messages.

[0062] S13. After performing convolutional coding with a code rate of r2 and bit interleaving Π2 on the g2-bit constellation diagram information, the constellation diagram encoded information is obtained. Then, constellation diagram modulation processing is performed to obtain the constellation diagram symbol information. The constellation diagram symbol information is a vector, used... Representation. Assuming the modulation order is M, then the constellation diagram symbol information... The number of bits transmitted is:

[0063] g2=Gr2k log2 M (2)

[0064] S14. Based on the obtained constellation symbol information By multiplying with the data arrangement matrix D, the information of each constellation symbol is obtained. The data is moved to the active subcarrier to obtain the OFDM-IM data block.

[0065] Preferred, definition and Let represent the active subcarrier number and SAP information of the t-th packet, respectively. Then the information of the r-th packet can be represented as:

[0066] x t =γD t s t (3)

[0067] in, This represents the power compensation factor, used to normalize the average power of the signal, i.e., to obtain E{x} H x}=n;D t The data permutation matrix (obtained from k columns of an n×n characteristic matrix) is used to represent constellation diagram symbol information. The various symbols were moved to SAP Information. On the corresponding active subcarrier, OFDM-IM data blocks are obtained.

[0068] For example, Table 1 gives a selection example when (n, k) = (4, 3), where each packet contains n = 4 subcarriers, and k = 3 subcarriers are activated in each time slot to transmit symbol information. The number of valid SAP messages is then... Minimum Hamming distance Each group of SAP messages carries two bits of additional information. In this example, the additional information and the index encoding information have a one-to-one mapping relationship.

[0069] Table 1 shows an example of a choice when (n, k) = (4, 3).

[0070]

[0071] S15. Through symbol interleaving (Π3), the symbol information of each group in the OFDM-IM data block is broken down. The broken symbol information is then processed by IFFT (Inverse Fast Fourier Transform) and CP (Cyclic Prefix) is added before data transmission.

[0072] Inter-symbol interference and inter-subcarrier interference are eliminated by adding a cyclic prefix.

[0073] Preferably, step S2 can be further refined into the following steps:

[0074] S21. Construct the receiving end, such as Figure 2 As shown. The transmitter transmits data to the receiver; after receiving the received information, the receiver demodulates the received information.

[0075] First, the received information undergoes CP removal, then FFT processing, and finally symbol deinterleaving. The system processes and obtains the processed received information, which includes SAP information and constellation symbol information.

[0076] Preferably, the processed received information is multiplied by a normalization factor 1 / γ, and the processed received information is represented in the frequency domain as follows:

[0077] y = HDs + v (4)

[0078] in, v represents additive complex Gaussian white noise with variance σ. 2 H represents the frequency domain channel matrix, which is a diagonal matrix with vector h as its diagonal elements. Here, h represents the symbol deinterleaving... The resulting CFR (Channel Frequency Response) can be expressed as:

[0079]

[0080] Among them, F L The Fourier transform matrix F represents the N×N dimension. N The N×L submatrix formed by the first L columns, Let P be an L×1 complex Gaussian random variable with zero mean and standard deviation. Let P be an L×L diagonal matrix, where the diagonal vector p represents the PDP (Power Delay Profile). The elements of the diagonal vector p are strictly positive, representing the power of each path channel gain, and the normalized total channel gain. Indicates F L Perform symbolic deinterleaving The matrix obtained after the corresponding row transformation.

[0081] Preferably, the received information after processing the t-th group can be represented in the frequency domain as:

[0082] y t =H t D t s t +v t (6)

[0083] Among them, H t The frequency domain channel matrix of the t-th group is represented by the CFR vector h of the t-th group. t A diagonal matrix with diagonal elements. v t This represents additive complex white Gaussian noise with variance .

[0084] S22. To improve the detection performance of SAP information and constellation symbol information contained in the processed received information, this embodiment designs a parallel feedback iterative detection method at the receiving end, which is implemented through an index information feedback iterative detection link and a constellation diagram information feedback iterative detection link, such as... Figure 2 As shown.

[0085] The SAP information is demodulated using an iterative detection link based on index information feedback. This involves calculating the log-likelihood ratio (LLR) for each bit carried by the SAP information to obtain the corresponding... Then bit deinterleaving is performed. The process then utilizes SISO (SoftInput SoftOutput) detection to obtain the LLR of the index information after convolutional encoding from ports P1(c;O) and P1(u;O) respectively. And the LLR of the index information bits; where, after the iteration ends, the LLR of the index information bits obtained from port P1(u;O) is the detection result of the index information.

[0086] S23. Demodulate the constellation diagram symbol information by using the constellation diagram information feedback iterative detection link, that is, perform LLR calculation on each bit in the constellation diagram symbol information to obtain... (1≤j≤k log2 M), then perform bit deinterleaving. The process then utilizes SISO detection to obtain the LLR of the constellation diagram information after convolutional encoding from ports P2(c;O) and P2(u;O), respectively. The LLR of constellation diagram information bits; where, after the iteration ends, the LLR of constellation diagram information bits obtained from port P2(u;O) is the detection result of constellation diagram information.

[0087] S24. The soft information obtained from the detection of two parallel branches will be cross-feeded, that is, in the index information feedback iterative detection link, the soft information will be cross-feeded. Perform bit interleaving (P1) processing to obtain SAP soft information. Next Feedback to the constellation chart information feedback iteration detection link; similarly, in the constellation chart information feedback iteration detection link, ... Perform bit interleaving (P2) processing to obtain constellation diagram symbol soft information. Next Feedback is sent to the index information feedback iteration detection link.

[0088] Preferably, χ is defined with These represent SAP information. The set of constellation symbol information s, and defined This represents constellation symbol information where the i-th bit is b∈{0,1}. The set of 1 ≤ i ≤ k log2 M, This represents SAP information where the i-th bit is b∈{0,1}. The set,

[0089] For the t-th packet, if the SAP information and constellation symbol information transmitted by the transmitter are... Then the receiving end The likelihood probability function can be expressed as:

[0090]

[0091] Where Λ represents n×1 dimensional additive white Gaussian noise v t The autocorrelation matrix can be expressed as

[0092] According to equation (7), the LLR of the i-th bit of the SAP information can be expressed as:

[0093]

[0094] By utilizing the constellation symbol soft information obtained through constellation symbol detection, the detection performance is improved, and the LLR of the i-th bit of the SAP information is corrected as follows:

[0095]

[0096] To avoid exponential operations and reduce computational complexity, the summation in equation (9) is approximated by a maximum value, i.e., log(x+…+y)≈max(log(x),…,log(y)). Therefore, equation (9) can be approximately expressed as:

[0097]

[0098] in,

[0099]

[0100] in, Information s representing constellation symbols t The j-th bit, express The probability of can be expressed as:

[0101]

[0102] in, This represents the constellation symbol soft information obtained by the t-th group after constellation symbol detection, which is initialized to a zero vector. Information s representing constellation symbols t LLR of the j∈1,…,k log2M bits.

[0103] Using the log-sum approximation, we can obtain:

[0104]

[0105] definition:

[0106]

[0107] By approximating equation (10), the LLR of each bit carried by the SAP information can be obtained; equation (10) can be approximated as:

[0108]

[0109] After obtaining the LLR of each bit carried by the SAP message, symbol deinterleaving is performed. After processing by the SISO detection module, the detection result of the index information finally obtained from port P1(u;O) can be expressed as:

[0110]

[0111] in, This represents the set of legal codewords for the corresponding convolutional encoding, and the detection complexity can be reduced by using the Viterbi algorithm.

[0112] Similarly, according to (7), constellation symbol information s t The j-th bit of the LLR can be represented as:

[0113]

[0114] By utilizing SAP soft information obtained through the detection of SAP information, detection performance can be improved by incorporating constellation symbol information. t The LLR correction for the j-th bit is:

[0115]

[0116] in,

[0117]

[0118] in, Indicates SAP information The corresponding i-th bit information, express The probability of can be expressed as:

[0119]

[0120] in, This represents the SAP soft information obtained by the SAP information detection of the t-th group, which is also initialized to a zero vector. This indicates that the SAP message carries additional information. Bit LLR.

[0121] Similarly, using log-sum, we can obtain:

[0122]

[0123] definition:

[0124]

[0125] By approximating equation (18), the LLR of each bit of the constellation diagram symbol information can be obtained; equation (18) can be approximated as:

[0126]

[0127] After obtaining the LLR of each bit of the constellation diagram symbol information, symbol deinterleaving is performed. After processing by the SISO detection module, the final detection result of the constellation diagram information obtained from the P2(u;O) port is as follows:

[0128]

[0129] Similarly, the above detection can be performed using the Viterbi algorithm to reduce the computational load.

[0130] S25. Continue to perform independent parallel detection, and set the number of iterations at the receiver as needed to obtain better detection performance;

[0131] When the detection performance remains essentially constant, stop the iteration and finally... and Obtain the detection results, including index information and constellation diagram information.

[0132] S26. Merge the detection results of the index information and constellation diagram information to obtain the output bit information.

[0133] Compared with Example 1, the method provided in this example further discloses the specific steps of an OFDM-IM transmission method using bit-interleaved coding modulation. Compared with the prior art, the maximum diversity order that existing indexed modulation OFDM can achieve is min(d free In this invention, the maximum obtainable diversity orders for SAP information and constellation symbol information are respectively (L). and min(d) free , L), where d free This represents the free distance between two convolutional codewords. For constellation diagram symbol information, the maximum diversity order achievable by this invention and the indexed modulation OFDM scheme is the same; however, for SAP information, considering the existence of different selection schemes for any SAP information... Therefore, this invention can achieve a larger diversity order. Figure 3 The transmission BER (Bit Error Rate) of this invention under different channel orders L; Figure 4 This paper compares the performance of the proposed BICM (Bit-Interleaved Coded Modulation)-OFDM-IM with existing BICM-OFDM schemes.

[0134] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An OFDM-IM transmission method employing bit-interleaved coding modulation, characterized in that, This includes data transmission methods and data reception methods; among which, The data transmission method includes: segmenting the input bit information to obtain index information and constellation diagram information; processing the index information and constellation diagram information to obtain SAP information and constellation diagram symbol information respectively; obtaining OFDM-IM data blocks based on the SAP information and constellation diagram symbol information, and transmitting the data after processing. The data receiving method includes: processing the received information; performing independent parallel detection on the processed received information to obtain SAP soft information and constellation symbol soft information respectively; using the SAP soft information to obtain the detection result of constellation information, and using the constellation symbol soft information to obtain the detection result of index information; merging the detection results of index information and constellation information to obtain output bit information. The processed received information is independently and in parallel detected to obtain SAP soft information, including: performing LLR calculation on the processed received information to obtain the LLR of the SAP information; and performing bit deinterleaving on the LLR of the SAP information. Processing, SISO detection processing, and bit interleaving Process and obtain SAP soft information; Independent parallel detection is performed on the processed received information to obtain constellation diagram symbol soft information, including: performing LLR calculation on the processed received information to obtain the LLR of constellation diagram symbol information; and performing bit deinterleaving on the LLR of constellation diagram symbol information. Processing, SISO detection processing, and bit interleaving Processing to obtain soft information about constellation symbols; The detection results of constellation diagram information obtained using the SAP soft information include: cross-feeding the SAP soft information and constellation diagram symbol soft information, correcting the LLR of constellation diagram symbol information using the SAP soft information, and continuing to perform independent parallel detection; when the detection performance remains unchanged, the iteration is stopped, and the detection results of constellation diagram information are obtained. The detection results of index information obtained using the constellation symbol soft information include: cross-feeding the SAP soft information and the constellation symbol soft information, correcting the LLR of the SAP information using the constellation symbol soft information, and continuing to perform independent parallel detection; when the detection performance remains unchanged, the iteration is stopped and the detection results of index information are obtained.

2. The OFDM-IM transmission method using bit-interleaved coding modulation according to claim 1, characterized in that, The index information is processed to obtain SAP information, including: The index information is sequentially processed by code rate Convolutional coding and bit interleaving Encoding processing yields index encoding information; The SAP information is obtained by index modulation of the index-encoded information.

3. The OFDM-IM transmission method using bit-interleaved coding modulation according to claim 1, characterized in that, The constellation diagram information is processed to obtain constellation symbol information, including: The constellation diagram information is sequentially processed using a code rate of Convolutional coding and bit interleaving Encoding processing yields constellation diagram encoding information; The constellation diagram encoding information is subjected to constellation diagram modulation to obtain the constellation diagram symbol information.

4. The OFDM-IM transmission method using bit-interleaved coding modulation according to any one of claims 1-3, characterized in that, The process of obtaining OFDM-IM data blocks based on SAP information and constellation diagram symbol information includes: Based on the SAP information, obtain the data arrangement matrix; The OFDM-IM data block is obtained by multiplying the data arrangement matrix with the constellation diagram symbol information.

5. The OFDM-IM transmission method using bit-interleaved coding modulation according to claim 1, characterized in that, The data transmission after processing includes: Symbol interleaving of the OFDM-IM data blocks The process involves breaking down the symbol information of each group. The information of each shuffled symbol is processed by IFFT and a cyclic prefix is ​​added before it is emitted.

6. The OFDM-IM transmission method using bit-interleaved coding modulation according to claim 1, characterized in that, Processing the received information includes: The received information is sequentially processed by removing cyclic prefixes, performing FFT processing, and symbol deinterleaving. Process the data to obtain the processed received information.

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