JP2007325079A - Radio communication system and communication method, and transmission apparatus and transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system in which a high diversity effect in the arbitrary number of antennas is made compatible with flexibility for a change in the number of antennas. <P>SOLUTION: In a transmission apparatus 1, an encoding means 11 performs error-correcting encoding on an inputted information sequence. An interleaver 12 interleaves the encoded information sequence. A symbol generating means 13 converts the interleaved information sequence into a symbol sequence. A frequency offset application means 14_1 to 14_M applies frequency offset to a plurality of symbol sequences so that a difference of all the frequency offsets to be applied to the plurality of symbol sequences resulting from branching the converted symbol sequence becomes an integer multiple, other than 0, of a predetermined frequency Δf. Radio units 15_1 to 15_M transmit the frequency offset applied symbol sequences via transmission antennas 16_1 to 16_M. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless communication system, a communication method, a transmission apparatus, and a transmission method that obtain a transmission diversity effect using a plurality of transmission antennas in a digital wireless communication system.

  In wireless communication, fading in which the reception level fluctuates due to multiple wave propagation, and transmission quality is greatly degraded due to a drop in the reception level. As a technique for reducing deterioration in transmission quality due to a drop in reception level, a diversity technique using two or more paths with low correlation of reception level fluctuation is known.

  Diversity technology can be broadly divided into time diversity and space diversity. Time diversity is a general term for diversity techniques that use two or more paths that are separated in time, such as a method of transmitting the same signal at different timings and selecting a signal with a high level. On the other hand, spatial diversity is a general term for diversity technology that uses two or more spatially separated paths, such as a method of preparing two or more antennas and selecting the antenna with the highest level.

  Among these, the time diversity has a long level fluctuation period, that is, when the moving speed of the terminal is slow, the correlation of paths that are separated in time increases, and the diversity effect is reduced. For this reason, application of space diversity is indispensable in order to transmit product quality with wireless terminals under various circumstances.

  Of the spatial diversity, transmission diversity implemented using multiple transmission antennas makes it difficult to estimate the channel response (amplitude phase response from the transmission antenna to the reception antenna) on the transmission side. A method that does not require information is required. One of the diversity methods that do not require channel information on the transmission side is a frequency offset transmission diversity method as disclosed in Patent Document 1.

  FIG. 11 is a diagram illustrating a wireless communication system 110 including a transmission apparatus 101 having two transmission antennas 116_1 and 116_2 and a reception apparatus 102 disclosed in Patent Document 1. In general, in the frequency offset transmission diversity method, transmission is performed by giving different frequency offsets to the transmission antennas 116_1 and 116_2 by the frequency offset assigning means 114_1 and 114_2. When a plurality of signals to which different frequency offsets are given are transmitted, the reception level fluctuates on the reception side due to the mutual frequency difference, and a steady drop in the reception level can be avoided.

Further, in the wireless communication system 110 disclosed in Patent Document 1, reception level fluctuation is forcibly generated, and reception quality of the demodulated information sequence varies due to reception level fluctuation. Therefore, the interleaver 112 and the reception side on the transmission side vary. Thus, the diversity effect is obtained by using the deinterleaver 125 to randomize the variation in the reception quality of the demodulated information sequence due to the variation in the reception level, and to relieve the random error due to the variation in the reception quality with the error correction code.
JP-A-3-135238

  By the way, in general, an error correction code has a high average reception quality in a short section of an information sequence input to its decoding means, that is, a constraint length or a block length of the error correction code, The smaller the variation, the higher the error correction capability. On the other hand, in the wireless communication system 110 described in Patent Document 1, the average reception quality of the entire information sequence does not change even if transmission is performed with any frequency offset.

 Therefore, in order to obtain a high diversity effect in the wireless communication system 110 described in Patent Document 1, the frequency offset adding means 114_1, 114_2, the interleaver 112, and the deinterleaver 125 have a constant average reception quality in a short section. In addition, it is required to reduce variations in reception quality in a short section.

 Further, in the wireless communication system 110 described in Patent Document 1, since the level variation pattern only changes even if the number of antennas is increased, the flexibility in changing the number of antennas is high, but the pattern of reception level variation has changed. In this case, if the structures of the interleaver 112 and the deinterleaver 125 are greatly different from the optimum structure after the pattern change, the error correction capability is lowered and the diversity effect is lowered. Therefore, a frequency offset applying method using the frequency offset applying means 114_1 and 114_2 that maintains a high diversity effect even when the number of antennas is changed, and a structure of the interleaver 112 and the deinterleaver 125 are required.

  However, in Patent Document 1, only the structure of the interleaver 112 in the case of the two transmission antennas 116_1 and 116_2 is empirically obtained, and a high diversity effect is realized with an arbitrary number of antennas, and the number of antennas is changed. Even in this case, there is a problem that the frequency offset applying method by the frequency offset applying means 114_1 and 114_2 and the structures of the interleaver 112 and the deinterleaver 125 that maintain a high diversity effect are not clarified.

  The present invention has been made to solve the above problems, and its purpose is to provide a high diversity effect at an arbitrary number of antennas by providing an appropriate frequency offset and an appropriate interleaver and deinterleaver structure in a frequency offset transmission diversity system. And a wireless communication system, a communication method, a transmission device, and a transmission method that achieve both flexibility in changing the number of antennas.

  In order to solve the above-described problem, the present invention includes a transmission apparatus that has a plurality of transmission antennas and performs transmission by a frequency offset transmission diversity method, and a reception apparatus that receives a radio signal from the transmission apparatus through a reception antenna. The transmission apparatus includes: an encoding unit that performs error correction encoding on an input information sequence; an interleaver that interleaves the information sequence encoded by the encoding unit; and the interleaver. Symbol generation means for converting an interleaved information series into a symbol series, and all frequency offsets assigned to each of a plurality of symbol series obtained by branching the symbol series converted by the symbol generation means So that the difference between the two is an integral multiple of the predetermined frequency Δf excluding zero. A plurality of frequency offset assigning means for assigning a frequency offset to a plurality of symbol sequences; and a transmitting means for transmitting the symbol sequence to which the frequency offset has been assigned by the frequency offset assigning means through the transmission antenna. Includes a receiving means for receiving a radio signal from the transmitting device through the receiving antenna, a detecting means for detecting a signal received by the receiving means and converting it to a symbol series, and a symbol sequence converted by the detecting means as information. Symbol identifying means for converting into a sequence, Deinterleaver for deinterleaving the information sequence converted by the symbol identifying means, and Decoding means for performing error correction decoding on the information sequence deinterleaved by the deinterleaver Is a wireless communication system.

  The present invention is a wireless communication system including a transmission device having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception device receiving a radio signal from the transmission device through a reception antenna. The transmission apparatus includes: an encoding unit that performs error correction encoding on an input information sequence; a symbol generation unit that converts an information sequence encoded by the encoding unit into a symbol sequence; and a conversion by the symbol generation unit The difference between all frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the symbol sequence interleaved by the interleaver and the symbol sequence interleaved by the interleaver is a predetermined frequency. The plurality of symbol sequences are set to be an integral multiple of Δf excluding 0. A plurality of frequency offset assigning means for assigning a frequency offset, and a transmitting means for transmitting the symbol sequence to which the frequency offset is provided by the frequency offset assigning means through the transmission antenna, wherein the receiving apparatus includes the receiving antenna Receiving means for receiving a radio signal from the transmitting device, detecting means for detecting a signal received by the receiving means and converting it to a symbol sequence, deinterleaver for deinterleaving the symbol sequence converted by the detecting means, A symbol identifying unit that converts the symbol sequence deinterleaved by the deinterleaver into an information sequence, and a decoding unit that performs error correction decoding on the information sequence converted by the symbol identifying unit. A wireless communication system.

  The present invention is characterized in that, in the above-described invention, the plurality of frequency offset applying units apply frequency offsets so that all the applied frequency offsets are arranged at equal intervals.

  According to the present invention, in the invention described above, the frequency offset assigning unit differs in the absolute value of the difference between two frequency offsets selected from all the frequency offsets to be applied in all combinations of the two frequency offsets. A frequency offset is given so as to be a value.

  In the present invention described above, the arbitrary natural number is q, the modulation multi-value number is k, the symbol rate is fs, and the maximum difference between the frequency offsets provided by the plurality of frequency offset assigning means is Δf. When the divided value is N, and an arbitrary natural number equal to or greater than q × (N + 1) is L, the interleaver determines that the consecutive L bits of the input information sequence are q × k × fs / Δf in the output information sequence. The bits are rearranged so as to be arranged in an arbitrary order of / L bit intervals, and the deinterleaver has L bits in which q × k × fs / Δf / L bit intervals of an input information sequence are arranged. In the output information series, the bits are rearranged so that they are arranged in an arbitrary order in consecutive L bits.

  According to the present invention, in the invention described above, an arbitrary natural number is q, a symbol rate is fs, and a value obtained by dividing a maximum value of a difference between frequency offsets provided by the plurality of frequency offset applying units by Δf is N, q When an arbitrary natural number equal to or greater than × (N + 1) is L, the interleaver is configured so that consecutive L symbols of the input symbol sequence are in any order of q × fs / Δf / L symbol intervals in the output symbol sequence. The deinterleaver performs rearrangement of symbols so that L symbols arranged at q × fs / Δf / L symbol intervals of the input symbol sequence are consecutive L symbols in the output information sequence. The symbols are rearranged so that they are arranged in an arbitrary order.

According to the present invention, in the above-described invention, when L is a power of 2 and r is any power of 2 between 2 and L, the interleaver inputs information about all possible r The deinterleaver performs the rearrangement of bits so that consecutive r bits of the sequence are arranged at q × k × fs / Δf / r bit intervals in the output information sequence,
For all possible r, bits are rearranged so that r bits arranged at q × k × fs / Δf / r bit intervals of the input information sequence are continuous in the output information sequence. And

  According to the present invention, in the above-described invention, when the L is a power of 2 and an arbitrary power of 2 between 2 and L is r, the interleaver inputs symbols for all possible r. The symbols are rearranged so that consecutive r symbols in the sequence are arranged at an interval of q × k × fs / Δf / r symbols in the output symbol sequence, and the deinterleaver inputs all possible r The symbol rearrangement is performed such that r symbols arranged at q × k × fs / Δf / r symbol intervals of the symbol sequences to be continued in the output symbol sequence.

  The present invention is the above described invention, wherein the interleaver has a matrix memory of L rows q × k × fs / Δf / L columns, and writes in the matrix memory in an arbitrary order in the column direction. The deinterleaver has a matrix memory of L rows q × k × fs / Δf / L columns, and writes to the matrix memory in the row direction in an arbitrary order. The matrix deinterleaver reads in the column direction in an arbitrary order.

  According to the present invention, in the above-described invention, the interleaver has a matrix memory of L rows q × fs / Δf / L columns, and writes the matrix memory in the column direction in an arbitrary order. The deinterleaver has a matrix memory of L rows q × fs / Δf / L columns, and writes to the matrix memory in the row direction in an arbitrary order. It is a matrix deinterleaver that reads in the column direction.

  According to the present invention, in the above-described invention, the interleaver is provided with row numbers to be written to the matrix memory and column numbers to be read from the matrix memory in ascending order, and the deinterleaver has the row numbers to be written to the matrix memory. The number and the column number to be read from the matrix memory are given in ascending order.

According to the present invention, in the invention described above, the interleaver has a number of rows L of the matrix memory that is a power of 2, and the number l of a row to be written to the matrix memory in the l-th (l is 0 to L-1). 'Is given as a value obtained by reversing the order of bits when l is expressed in a binary number of log ₂ (L) bits, and the deinterleaver is such that the number of rows L of the matrix memory is a power of 2. The number l ′ of the row written to the l-th (l is 0 to L−1) in the matrix memory is given as a value obtained by reversing the order of bits when l is represented by a binary number of log ₂ (L) bits. It is characterized by being able to.

According to the present invention, in the invention described above, the interleaver has a number of rows L of the matrix memory that is a power of 2, and the number l of a row to be written to the matrix memory in the l-th (l is 0 to L-1). 'Is given as a value obtained by reversing the order of symbols when l is represented by a binary number of log ₂ (L) symbols, and the deinterleaver is such that the number of rows L of the matrix memory is a power of 2. The number l ′ of the row written to the l-th (l is 0 to L−1) in the matrix memory is given as a value obtained by reversing the arrangement of the symbols when l is displayed as a binary number of log ₂ (L) symbols. It is characterized by being able to.

  The present invention is a communication method performed by a transmission apparatus having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception apparatus receiving a radio signal from the transmission apparatus through a reception antenna, In the transmission apparatus, an error correction encoding step of an input information sequence, an interleaving step of the encoded information sequence, a step of converting the interleaved information sequence into a symbol sequence, and the converted symbol sequence branch The frequency for the plurality of symbol sequences is such that the difference between all the frequency offsets assigned to each of the plurality of symbol sequences obtained as a result is an integer multiple of the predetermined frequency Δf excluding 0. A step of assigning an offset, and a symbol sequence to which the frequency offset is assigned Transmitting through a transmitting antenna, and receiving at the receiving device a radio signal from the transmitting device through the receiving antenna, detecting the received signal and converting it to a symbol sequence, and converting A communication method comprising: converting a symbol sequence into an information sequence; deinterleaving the converted information sequence; and performing error correction decoding on the deinterleaved information sequence.

  The present invention is a communication method performed by a transmission apparatus having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception apparatus receiving a radio signal from the transmission apparatus through a reception antenna, In the transmission apparatus, an error correction encoding step of an input information sequence, a step of converting the encoded information sequence into a symbol sequence, a step of interleaving the converted symbol sequence, and an interleaved symbol sequence are: For the plurality of symbol sequences, the difference between all the frequency offsets assigned to each of the plurality of symbol sequences obtained by branching is an integer multiple of the predetermined frequency Δf excluding 0. A step of assigning a frequency offset, and a symbol system to which the frequency offset is assigned Transmitting through the transmitting antenna, and receiving at the receiving device a radio signal from the transmitting device through the receiving antenna, detecting the received signal and converting it to a symbol sequence, and detecting A communication method comprising the steps of: deinterleaving the converted symbol sequence; converting the deinterleaved symbol sequence into an information sequence; and error correcting decoding the converted information sequence.

  The present invention is characterized in that, in the above-described invention, in the step of applying the frequency offset, the frequency offset is applied so that all the applied frequency offsets are arranged at equal intervals.

  In the invention described above, the absolute value of the difference between two frequency offsets selected from all the frequency offsets to be applied is a combination of all two frequency offsets in the step of giving the frequency offsets in the invention described above. The frequency offset is applied so as to have different values.

  In the present invention described above, the arbitrary natural number is q, the modulation multi-value number is k, the symbol rate is fs, and the maximum difference between the frequency offsets provided by the plurality of frequency offset assigning means is Δf. When an arbitrary natural number equal to or greater than N and q × (N + 1) is L, the consecutive L bits of the input information sequence are q × k × in the output information sequence in the interleaving step. The bits are rearranged so as to be arranged in an arbitrary order of fs / Δf / L bit interval, and in the deinterleaving step, q × k × fs / Δf / L bit interval of the input information sequence The bit rearrangement is performed such that the L bits to be arranged are arranged in an arbitrary order on consecutive L bits in the information sequence to be output.

  According to the present invention, in the invention described above, an arbitrary natural number is q, a symbol rate is fs, and a value obtained by dividing a maximum value of a difference between frequency offsets provided by the plurality of frequency offset applying units by Δf is N, q When an arbitrary natural number greater than or equal to (N + 1) is L, in the interleaving step, consecutive L symbols of the input symbol series are arbitrarily set to q × fs / Δf / L symbol intervals in the output symbol series. Are rearranged so that the symbols are arranged in the following order, and in the deinterleaving step, L symbols arranged at intervals of q × fs / Δf / L symbol intervals of input symbol sequences are output. The symbols are rearranged so as to be arranged in an arbitrary order in consecutive L symbols in FIG.

  The present invention is a transmission apparatus having a plurality of transmission antennas and performing transmission by a frequency offset transmission diversity method, encoding means for error-correcting an input information sequence, and encoding by the encoding means An interleaver that interleaves the generated information sequence, a symbol generation unit that converts the information sequence interleaved by the interleaver into a symbol sequence, and a plurality of symbols obtained by branching the symbol sequence converted by the symbol generation unit A plurality of frequency offset assignments for applying a frequency offset to the plurality of symbol series so that a difference between all frequency offsets to be assigned to each of the series is an integer multiple excluding 0 of a predetermined frequency Δf. And frequency offset by the frequency offset applying means. There is a transmission apparatus characterized by comprising a transmitting means for transmitting the assigned symbol sequence through the transmitting antenna.

  The present invention is a transmission apparatus having a plurality of transmission antennas and performing transmission by a frequency offset transmission diversity method, encoding means for error-correcting an input information sequence, and encoding by the encoding means A symbol generating means for converting the converted information series into a symbol series, an interleaver for interleaving the symbol series converted by the symbol generating means, and a plurality of symbols obtained by branching the symbol series interleaved by the interleaver A plurality of frequency offset assignments for applying a frequency offset to the plurality of symbol series so that a difference between all frequency offsets to be assigned to each of the series is an integer multiple excluding 0 of a predetermined frequency Δf. And frequency off by the frequency offset applying means The symbol sequence Tsu bets is imparted, characterized in that a transmission means for transmitting via the transmitting antenna.

  The present invention is characterized in that, in the above-described invention, the plurality of frequency offset applying units apply frequency offsets so that all the applied frequency offsets are arranged at equal intervals.

  According to the present invention, in the invention described above, the frequency offset assigning unit differs in the absolute value of the difference between two frequency offsets selected from all the frequency offsets to be applied in all combinations of the two frequency offsets. A frequency offset is given so as to be a value.

  In the present invention described above, the arbitrary natural number is q, the modulation multi-value number is k, the symbol rate is fs, and the maximum difference between the frequency offsets provided by the plurality of frequency offset assigning means is Δf. When the divided value is N, and an arbitrary natural number equal to or greater than q × (N + 1) is L, the interleaver determines that the consecutive L bits of the input information sequence are q × k × fs / Δf in the output information sequence. The bit rearrangement is performed so as to be arranged in any order of / L bit intervals.

  According to the present invention, in the invention described above, an arbitrary natural number is q, a symbol rate is fs, and a value obtained by dividing a maximum value of a difference between frequency offsets provided by the plurality of frequency offset applying units by Δf is N, q When an arbitrary natural number equal to or greater than × (N + 1) is L, the interleaver is configured so that consecutive L symbols of the input symbol sequence are in any order of q × fs / Δf / L symbol intervals in the output symbol sequence. The symbols are rearranged so that they are arranged.

  The present invention is a transmission method in a transmission apparatus that has a plurality of transmission antennas and performs transmission in a frequency offset transmission diversity system, the step of performing error correction encoding on an input information sequence, and an encoded information sequence. The step of interleaving, the step of converting the interleaved information sequence into a symbol sequence, and the difference between all frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the converted symbol sequence, Assigning a frequency offset to the plurality of symbol sequences so as to be an integer multiple excluding 0 of a predetermined frequency Δf, and transmitting the symbol sequences to which the frequency offset is assigned through the transmission antenna; Is included in the transmission method.

  The present invention relates to a transmission method in a transmission apparatus that has a plurality of transmission antennas and performs transmission by a frequency offset transmission diversity method, the step of performing error correction encoding on an input information sequence, and an encoded information sequence. A step of converting to a symbol sequence, a step of interleaving the converted symbol sequence, and a difference between all frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the interleaved symbol sequence. Applying a frequency offset to the plurality of symbol sequences so as to be an integer multiple excluding 0 of a predetermined frequency Δf, and transmitting the symbol sequence to which the frequency offset is applied through the transmission antenna; Is included in the transmission method.

  The present invention is characterized in that, in the above-described invention, in the step of applying the frequency offset, the frequency offset is applied so that all the applied frequency offsets are arranged at equal intervals.

The present invention provides the frequency offset in the above-described invention,
The frequency offset is given so that the absolute value of the difference between the two frequency offsets selected from all the frequency offsets to be given becomes a different value in the combination of all the two frequency offsets.

  In the present invention described above, the arbitrary natural number is q, the modulation multi-value number is k, the symbol rate is fs, and the maximum difference between the frequency offsets provided by the plurality of frequency offset assigning means is Δf. When an arbitrary natural number equal to or greater than N and q × (N + 1) is L, the consecutive L bits of the input information sequence are q × k × in the output information sequence in the interleaving step. Bits are rearranged so that they are arranged in an arbitrary order of fs / Δf / L bit intervals.

  According to the present invention, in the invention described above, an arbitrary natural number is q, a symbol rate is fs, and a value obtained by dividing a maximum value of a difference between frequency offsets provided by the plurality of frequency offset applying units by Δf is N, q When an arbitrary natural number greater than or equal to (N + 1) is L, in the interleaving step, consecutive L symbols of the input symbol series are arbitrarily set to q × fs / Δf / L symbol intervals in the output symbol series. The symbols are rearranged so that they are arranged in this order.

  According to the present invention, a transmission apparatus in a wireless communication system interleaves an encoded information sequence by an interleaver, converts the interleaved information sequence into a symbol sequence, and a plurality of symbol sequences obtained by branching the converted symbol sequence Frequency offset assigning means for assigning frequency offsets to a plurality of symbol sequences so that the difference between all frequency offsets to be assigned to each of the symbol sequences is an integer multiple of a predetermined frequency Δf excluding 0. It was set as the structure which comprises. As a result, the frequency difference between frequency offsets is an integer multiple of Δf excluding 0, so that every time T (= 1 / Δf) regardless of the number of antennas M or the maximum difference between the frequency offsets to be applied. Therefore, it is possible to design an interleaver that realizes a high diversity effect and flexibility in changing the number of antennas.

  Further, according to the present invention, a transmitting apparatus in a radio communication system obtains an encoded information sequence by converting it into a symbol sequence, interleaves the converted symbol sequence by interleaving, and the interleaved symbol sequence is branched. A frequency at which a frequency offset is given to the plurality of symbol sequences so that a difference between all frequency offsets to be assigned to each of the plurality of symbol sequences is an integer multiple of a predetermined frequency Δf excluding 0. It was set as the structure provided with an offset provision means. As a result, the frequency difference between frequency offsets is an integer multiple of Δf excluding 0, so that every time T (= 1 / Δf) regardless of the number of antennas M or the maximum difference between the frequency offsets to be applied. Therefore, it is possible to design an interleaver that realizes a high diversity effect and flexibility in changing the number of antennas. Also, since interleaving and deinterleaving are performed on symbols, the size of the interleaver and deinterleaver is reduced, and a reduction in circuit scale can be expected.

  Further, according to the present invention, the frequency offset providing means in the wireless communication system is configured to apply the frequency offset so that all the applied frequency offsets are arranged at equal intervals. As a result, the maximum absolute value of the frequency offset difference can be reduced, so that it is possible to reduce the degradation of reception quality due to high-speed fading.

  Further, according to the present invention, the frequency offset assigning means in the radio communication system has different absolute values of the difference between two frequency offsets selected from all the frequency offsets to be applied in all combinations of the two frequency offsets. It was set as the structure which gives a frequency offset so that it may become a value. Thereby, since the dispersion of the reception level fluctuation does not have the phase dependence of the channel response, a stable diversity effect can be obtained regardless of the phase relationship of the channel response.

  Further, according to the present invention, in a wireless communication system, an arbitrary natural number q, a modulation multi-value number k, a symbol rate fs, and a maximum difference between frequency offsets provided by the plurality of frequency offset assigning means are set. When the value divided by Δf is N and an arbitrary natural number equal to or greater than q × (N + 1) is L, the interleaver determines that the consecutive L bits of the input information sequence are q × k × fs / in the output information sequence. The bits are rearranged so that they are arranged in an arbitrary order of Δf / L bit intervals, and the deinterleaving provided in the receiving apparatus is arranged at q × k × fs / Δf / L bit intervals of the input information sequence. The bits are rearranged so that the L bits are arranged in an arbitrary order in consecutive L bits in the information sequence to be output. Thereby, the average reception quality of the short section in the information sequence after deinterleaving becomes constant, the error correction capability can be improved, and a high diversity effect can be obtained. Further, even when the value of N (for example, the number of transmission antennas) changes depending on the situation, if L is set so as to be able to handle the assumed maximum N, the information sequence after deinterleaving The average reception quality of consecutive L bits can be made constant, and a diversity effect according to the value of N can be obtained.

  Further, according to the present invention, in a wireless communication system, an arbitrary natural number is q, a symbol rate is fs, and a value obtained by dividing a maximum value of a difference between frequency offsets provided by the plurality of frequency offset assigning units by Δf is N , Q × (N + 1) or more, if an arbitrary natural number is L, the interleaver selects an arbitrary sequence of q × fs / Δf / L symbol intervals in an output symbol sequence in which consecutive L symbols of the input symbol sequence are output. The symbols are rearranged so as to be arranged in the deinterleaving of the receiving apparatus. The deinterleaving provided in the receiving apparatus is such that L symbols arranged at q × fs / Δf / L symbol intervals of the input symbol series are continuous in the output information series. The symbols are rearranged so that the L symbols are arranged in an arbitrary order. Thereby, the average reception quality of the short section in the information sequence after deinterleaving becomes constant, the error correction capability can be improved, and a high diversity effect can be obtained. Further, even when the value of N (for example, the number of transmission antennas) changes depending on the situation, if L is set so as to be able to handle the assumed maximum N, the information sequence after deinterleaving The average reception quality of consecutive L symbols can be made constant, and a diversity effect according to the value of N can be obtained.

  Further, according to the present invention, in a wireless communication system, when L is a power of 2 and any power of 2 between 2 and L is r, the interleaver inputs information for all possible r The bits are rearranged so that consecutive r bits of the sequence are arranged at an interval of q × k × fs / Δf / r bits in the output information sequence, and the deinterleaver included in the receiving apparatus has all possible r In the configuration, the bits are rearranged so that r bits arranged at q × k × fs / Δf / r bit intervals of the input information sequence are continuous in the output information sequence. As a result, even if L is set to a large value in order to cope with a large value of N, when the value of N is small (for example, when the number of transmission antennas is small), a decrease in diversity effect due to a decrease in error correction capability is suppressed. be able to.

  Further, according to the present invention, in a wireless communication system, when L is a power of 2 and any power of 2 between 2 and L is r, the interleaver can input symbols for all possible r. The symbols are rearranged so that consecutive r symbols in the sequence are arranged at an interval of q × k × fs / Δf / r symbols in the output symbol sequence, and the deinterleaver provided in the receiving apparatus has all the possible r In the configuration, the symbols are rearranged so that r symbols arranged at q × k × fs / Δf / r symbol intervals of the input symbol series are continuous in the output symbol series. As a result, even if L is set to a large value in order to cope with a large value of N, when the value of N is small (for example, when the number of transmission antennas is small), a decrease in diversity effect due to a decrease in error correction capability is suppressed. be able to.

  According to the present invention, in the wireless communication system, the interleaver has a matrix memory of L rows q × k × fs / Δf / L columns, and writes the matrix memories in the column direction in an arbitrary order. A matrix interleaver that reads out in an arbitrary order in a row direction, and a deinterleaver included in the reception apparatus includes a matrix memory of L rows q × k × fs / Δf / L columns, and the matrix memory in an arbitrary order. The matrix deinterleaver is configured to write in the row direction and read in the column direction in an arbitrary order. As a result, the L bits arranged at intervals of q × k × fs / Δf / L bits of the information sequence input to the interleaver and deinterleaver are arranged in a specific column regardless of the order of writing to the matrix memory. Can do.

  Further, according to the present invention, in the wireless communication system, the interleaver has a matrix memory of L rows q × fs / Δf / L columns, writes the matrix memory in the column direction in an arbitrary order, A matrix interleaver that reads in the row direction in order, and the deinterleaver provided in the receiving apparatus has a matrix memory of L rows q × fs / Δf / L columns, and writes in the row direction in an arbitrary order to the matrix memory The matrix deinterleaver reads in the column direction in any order. As a result, L bits arranged at q × fs / Δf / L symbol intervals of the information sequence input to the interleaver and deinterleaver are arranged in a specific column, regardless of the order of writing to the matrix memory. be able to.

  According to the present invention, in the wireless communication system, the interleaver is given the row numbers to be written to the matrix memory and the column numbers to be read from the matrix memory in ascending order, and the deinterleaver included in the receiving device writes to the matrix memory. Row numbers and column numbers read from the matrix memory are given in ascending order. As a result, the circuit scale of the interleaver and deinterleaver can be reduced.

Further, according to the present invention, in the wireless communication system, the interleaver has a matrix memory row number L that is a power of 2, and the row number l ′ to be written to the matrix memory in the l-th (l is 0 to L−1). Is given as a value obtained by reversing the order of bits when l is expressed in a binary number of log ₂ (L) bits, and the deinterleaver included in the receiving device has a matrix memory row number L that is a power of 2 The number l ′ of the row written to the matrix memory in the l-th (l is 0 to L−1) is given as a value obtained by reversing the order of the bits when l is represented by a binary number of log ₂ (L) bits. It was set as the structure. As a result, when r ′ is a power of 2 greater than or equal to q × (N + 1), it is possible to make the average reception quality of arbitrary r ′ bits continuous in the information sequence after deinterleaving constant. Become.

Further, according to the present invention, in the wireless communication system, the interleaver has a matrix memory row number L that is a power of 2, and the row number l ′ to be written to the matrix memory in the l-th (l is 0 to L−1). Is given as a value obtained by reversing the order of symbols when l is represented by a binary number of log ₂ (L) symbols, and the deinterleaver included in the receiving device has a matrix memory row number L that is a power of 2 The number l ′ of the row written to the matrix memory in the l-th (l is 0 to L−1) is given as a value obtained by reversing the arrangement of symbols when l is displayed as a binary number of log ₂ (L) symbols. It was set as the structure. As a result, when r ′ is a power of 2 greater than or equal to q × (N + 1), it is possible to make the average reception quality of arbitrary r ′ symbols that are continuous in the information sequence after deinterleaving constant. Become.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing a radio communication system 100 according to the first embodiment of the present invention. The wireless communication system 100 includes a transmission device 1 and a reception device 2, and performs communication using a frequency offset transmission diversity method by interleaving and deinterleaving information sequences before symbol generation and after symbol identification, respectively.

  In the wireless communication system 100, the transmission apparatus 1 includes an encoding unit 11, an interleaver 12, a symbol generation unit 13, M frequency offset assignment units 14_1 to 14_M, radio units 15_1 to 15_M, and transmission antennas 16_1 to 16_M. Yes. The encoding means 11 performs error correction encoding on the input information sequence S10. The interleaver 12 interleaves the information sequence S11 encoded by the encoding means 11. The symbol generation means 13 converts the information sequence S12 interleaved by the interleaver 12 into a symbol sequence. The frequency offset assigning units 14_1 to 14_M assign independent frequency offsets to the symbol series S13 converted by the symbol refining unit 13, respectively. The radio units 15_1 to 15_M transmit the transmission signals S15_1 to S15_M obtained by performing analog conversion and frequency conversion on the symbol sequences S14_1 to S14_M to which the frequency offset is added by the frequency offset adding unit 14_1 to 14_M through the transmission antennas 16_1 to 16_M. To do.

 The receiving device 2 includes a receiving antenna 21, a radio unit 22, a detecting unit 23, a symbol identifying unit 24, a deinterleaver 25, and a decoding unit 26. The reception antenna 21 receives a radio signal transmitted from the transmission device 1. The radio unit 22 performs frequency conversion and conversion to a digital signal on the reception signal S21 received through the reception antenna 21. The detection means 23 detects the digital signal S22 converted by the radio unit 22 and converts it into a symbol series. The symbol identification means 24 converts the symbol series S23 after detection by the detection means 23 into an information series. The deinterleaver 25 deinterleaves the converted information sequence S24. The decoding unit 26 corrects the error included in the deinterleaved information sequence S25 and outputs the information sequence S26. The wireless communication system 100 according to the first embodiment is different from the conventional one in that detailed operations of the interleaver 12, the frequency offset assigning units 14_1 to 14_M, and the deinterleaver 25 are defined. Hereinafter, these detailed operations will be described.

  Next, the operation of the frequency offset applying means 14_1 to 14_M will be described with reference to FIG. The frequency offset applying means 14_1 to 14_M applies the frequency offset so that the frequency difference between the frequency offsets is an integral multiple of Δf excluding 0. For example, as shown in FIG. 2, the frequency offset is given so that the frequency offsets are arranged at equal intervals of Δf. When the frequency offset is applied in this way, the frequency offset to be applied can be made dense, so that the maximum absolute value of the difference between the frequency offsets applied by the different frequency offset applying units 14_1 to 14_M can be reduced.

As shown in FIG. 2, when applied at equal intervals on the frequency offset Δf intervals, the symbol sequence S13 which is outputted from the symbol generating unit 13 s (t), the carrier frequency is f _c, m th transmit antenna 16_m Assuming that the transmission signal S15_1 transmitted from is a signal x _m (t), the signal x _m (t) is expressed by the following equation (1).

Here, if the channel response between the mth transmitting antenna 16_m and the receiving antenna 21 is α _m , the reception level p (t) of the received signal S21 at the receiving antenna 21 is expressed by the following equation (2.1). Will be. Note that φ (t) in equation (2.1) is defined by equation (2.2).

  Thus, when the frequency offset applying means 14_1 to 14_M applies M frequency offsets at equal intervals of Δf, the reception level p (t) of the received signal S21 at the receiving antenna 21 is increased from 1 times Δf to M. It can be expressed by M-1 sine waves up to -1 times and a constant.

  When the frequency offset is given so that the frequency difference between the frequency offsets is an integer multiple of Δf excluding 0, the reception level of the reception signal S21 is obtained by performing the same equation expansion as equation (2.1). p (t) is a sine wave and a constant that are equal to or less than N times Δf (N is a value obtained by dividing the maximum difference between the frequency offsets to be applied by Δf) or an integer multiple of Δf excluding 0. Will be represented.

  Here, assuming that T = 1 / Δf, an integral multiple sine wave excluding 0 of Δf has a result of integration over time T of 0, so that the frequency difference between frequency offsets excludes 0 of Δf. When a frequency offset is given so as to be an integral multiple, the average reception level for each time T is always constant.

  In this way, by giving the frequency offset so that the frequency difference between the frequency offsets is an integer multiple of Δf excluding 0, regardless of the maximum value of the difference between the number M of transmission antennas and the given frequency offset, Since the average reception level (average reception quality) for each time T is constant, the interleaver 12 and the deinterleaver 25 can be designed to realize a high diversity effect and flexibility in changing the number of transmission antennas.

  By the way, in the frequency offset transmission diversity system, fading is forcibly generated on the receiving side due to the frequency difference between each other by transmitting a plurality of signals given different frequency offsets. The speed of the fading fluctuation generated forcibly is determined by the maximum absolute value of the difference between the frequency offsets applied by the different frequency offset applying units 14_1 to 14_M. In addition, when the speed of fading fluctuation is high, the amount of phase change per symbol increases, and the reception quality deteriorates because it falls outside the APC (Auto Phase Control) pull-in range.

  As described above, if the frequency offset is applied so that the frequency offsets are arranged at equal intervals of Δf, the maximum absolute value of the difference between the frequency offsets applied by the different frequency offset applying units 14_1 to 14_M can be reduced. Degradation of reception quality due to high-speed fading can be reduced.

  Next, a detailed operation of the deinterleaver 25 in the receiving device 2 will be described. First, an arbitrary natural number q, a modulation multilevel number k, a symbol rate fs, a value obtained by dividing a maximum difference between given frequency offsets by Δf, N, and an arbitrary natural number equal to or greater than q × (N + 1) Let L be L. At this time, in the deinterleaver 25, L bits arranged at q × k × fs / Δf / L bit intervals of the information sequence input to the deinterleaver 25 are continuous in the information sequence S25 output from the deinterleaver 25. The bits are rearranged so that they are arranged in L bits in an arbitrary order. By performing such an operation, the average reception level of the reception signal S21 used to generate continuous L bits of the information series S25 is always constant. Hereinafter, the principle will be described using mathematical expressions.

  First, in order to simplify the description, the case where the frequency offset applying units 14_1 to 14_M apply frequency offsets at equal intervals of Δf as shown in FIG. 2 will be considered below. At this time, the above-described N is N = M−1. First, in order to estimate the average reception level of the reception signal S21 used to generate consecutive L bits of the information series S25, L terms φ (t) that fluctuate at the reception level p (t) are collected at intervals τ. Consider the sum of times g (t). At this time, g (t) is expressed by the following equation (3).

Here, the condition of τ where g _i (t) = 0 at an arbitrary time t is expressed by the following equation (4).

However, alpha _i is, L-1 following an arbitrary natural number, b _i is given by any integer of 0 or more. In order to satisfy g (t) = 0 at an arbitrary time t, all g _i (t) must be equal to g _i (t) = 0 at an arbitrary time t. Such τ is given by the following equation (5).

  However, in Formula (5), q is given by an arbitrary natural number, and L is given by an arbitrary natural number of q × M or more, that is, an arbitrary natural number of q × (N + 1) or more. From the above, it can be seen that when L terms φ (t) that change with time at intervals of q / Δf / L are collected, the sum g (t) becomes 0 and the average reception level of the reception signal S21 becomes constant.

  As described above, when the deinterleaver 25 is used, the average reception level of the reception signal S21 corresponding to L bits used to generate the continuous L bits of the information sequence S25 is fixed. The reception quality of the information sequence S25 is determined by the reception level p (t) of the reception signal S21 at the reception antenna 21. Therefore, when the deinterleaver 25 is used, the average reception quality in the short section of the information sequence S25 becomes constant. Thereby, the error correction capability of the decoding means 26 can be improved, and as a result, a high diversity effect can be obtained.

  Further, when the deinterleaver 25 is used, if L is equal to or greater than q × (N + 1), the average reception quality of consecutive L bits of the information sequence S25 is constant. Therefore, when the value of N changes depending on the situation, for example, even when the number of transmission antennas changes, if L is set so as to be compatible with the maximum possible N, the information sequence S25 is always continuous. The average reception quality of L bits is constant. As described above, by using the interleaver 12 and the deinterleaver 25 set so as to be able to cope with the maximum N assumed L, it is possible to obtain a diversity effect according to the number of transmission antennas without changing the structure. .

  Further, L bits arranged at q × k × fs / Δf / L bit intervals of the information sequence input to the deinterleaver 25 are arranged in an arbitrary order to L bits continuous in the information sequence S25 output from the deinterleaver 25. The operation of rearranging the bits so as to be arranged in the above is provided with a matrix memory of L rows q × fs / Δf / L columns, written to the matrix memory in an arbitrary order in the column direction, and in an arbitrary order This can be realized by a matrix interleaver that reads in the row direction. In the matrix interleaver, L bits arranged at intervals of q × k × fs / Δf / L bits of the information sequence input to the deinterleaver 25 are arranged in a specific column regardless of the order of writing to the matrix memory. It is.

  There are various variations in the matrix interleaver depending on the order of the rows and columns to be written in the matrix memory. Among them, the order of the rows to be written in the matrix memory and the order of the columns to be read as shown in FIG. The matrix interleaver given below (hereinafter referred to as a simple interleaver) is an interleaver that can be implemented with the smallest circuit scale. FIG. 3 shows the configuration of the matrix interleaver when q = 1, k = 1, fs / Δf = 32, and L = 4.

  Next, the detailed operation of the interleaver 12 will be described. The interleaver 12 performs exactly the reverse operation to the deinterleaver 25 described above in order to align the order of the information sequence S11 output from the encoding unit 11 and the information sequence S25 input to the decoding unit 26. That is, the bits are rearranged so that consecutive L bits of the information sequence S11 are arranged at q × k × fs / Δf / L bit intervals in the information sequence S12. Further, the interleaver 12 can be realized by a matrix interleaver similarly to the deinterleaver 25 described above, and the circuit scale can be reduced by using a simple matrix interleaver.

  5 shows a scheme using the simple matrix interleaver shown in FIG. 3 in the wireless communication system 100 according to the first embodiment under the conditions shown in FIG. 4 (hereinafter referred to as “Scheme A in the text, FIGS. 4 and 5). The simulation results for the SNR (Signal to Noise Ratio) vs. BLER (Block Error Rate) characteristics are shown. For comparison, FIG. 5 shows the frequency arrangement in the first embodiment with respect to the interleaver 12, the deinterleaver 25, and the frequency offset means 14_1 to 14_M in the same configuration as the radio communication system 100 shown in FIG. And a simulation result of the SNR vs. BLER characteristic in the case of a method that does not rearrange bits (hereinafter referred to as “method C” in the text and FIG. 5).

  As is clear from FIG. 5, it can be seen that the scheme A by the wireless communication system 100 according to the first embodiment has better SNR vs. BLER characteristics than the scheme C. It can also be confirmed that when the number of transmission antennas is increased from 3 to 6, a high diversity effect according to the number of transmission antennas is obtained.

(Second Embodiment)
FIG. 6 is a block diagram showing a radio communication system 101 according to the second embodiment of the present invention. The wireless communication system 101 includes a transmission device 3 and a reception device 4, and is configured to perform communication using a frequency offset transmission diversity method by interleaving and deinterleaving information sequences after symbol generation and before symbol identification. Different from the wireless communication system 100 according to the first embodiment.

  In the wireless communication system 101, the transmission apparatus 3 includes an encoding unit 31, a symbol generation unit 32, an interleaver 33, frequency offset addition units 34_1 to 34_M, radio units 35_1 to 35_M, and transmission antennas 36_1 to 36_M. The encoding unit 31 performs error correction encoding on the input information sequence S30, and the symbol generation unit 32 converts the information sequence S31 encoded by the encoding unit 31 into a symbol sequence. The interleaver 33 interleaves the symbol series S32 converted by the symbol generation means 32. The frequency offset assigning units 34_1 to 34_M assign independent frequency offsets to the symbol series S33 interleaved by the interleaver 33. The radio units 35_1 to 35_M perform analog conversion and frequency conversion on the symbol sequences S34_1 to S34_M to which the frequency offset has been added by the frequency offset assigning units 34_1 to 34_M, and transmit the signals S35_1 to S35_M through the transmission antennas 36_1 to 36_M. .

  The reception device 4 includes a reception antenna 41, a radio unit 42, a detection unit 43, a deinterleaver 44, a symbol identification unit 45, and a decoding unit 46. The receiving antenna 41 receives a radio signal. The radio unit 42 performs frequency conversion and digital signal conversion on the signal S41 received by the receiving antenna 41. The detection means 43 detects the digital signal S42 converted by the radio unit 42 and converts it into a symbol series S43. The deinterleaver 44 deinterleaves the symbol series S43 after detection by the detection means 43. The symbol identifying means 45 converts the symbol sequence S44 deinterleaved by the deinterleaver 44 into an information sequence S45. The decoding unit 46 corrects the error included in the converted information sequence S45 and outputs the information sequence S46. The wireless communication system 101 according to the second embodiment is different from the conventional one in that detailed operations of the interleaver 33, the frequency offset assigning units 34_1 to 34_M, and the deinterleaver 44 are defined. Hereinafter, these detailed operations will be described.

  Similarly to the frequency offset applying units 14_1 to 14_M according to the first embodiment, the frequency offset applying units 34_1 to 34_M apply the frequency offset so that the frequency difference between the frequency offsets is an integral multiple of Δf excluding 0. Also, in the frequency offset assigning means 34_1 to 34_M, similarly to the frequency offset giving means 14_1 to 14_M according to the first embodiment, by giving the frequency offset so that the frequency offsets are arranged at equal intervals of Δf, Degradation of reception quality due to high-speed fading can be reduced.

  The deinterleaver 44 performs the same operation on the symbols as the deinterleaver 25 of the first embodiment performs on the bits. That is, the symbols are rearranged so that the L symbols arranged at the q × fs / Δf / L symbol interval of the symbol information sequence S43 are continuous in the information sequence S44. Similarly to the deinterleaver 25, the deinterleaver 44 can be realized by a matrix interleaver, and the circuit scale can be reduced by using a simple matrix interleaver.

  In the interleaver 33, in order to align the order of the information sequence S 31 output from the encoding unit 31 and the information sequence S 45 input to the decoding unit 46, the interleaver 33 performs an operation completely opposite to that of the deinterleaver 44 described above. That is, the symbols are rearranged so that the L symbols that continue in succession in the symbol series S32 are arranged in the information series S33 at intervals of q × fs / Δf / L symbols. Similarly to the deinterleaver 25 of the first embodiment, the interleaver 33 can be realized by a matrix interleaver, and the circuit scale can be reduced by using a simple matrix interleaver.

  In the transmission device 3 and the reception device 4 according to the second embodiment, since interleaving and deinterleaving are performed on the symbols, the modulation multi-level number is larger than that of the transmission device 1 and the reception device 2 according to the first embodiment. Is 2 or more, the sizes of the interleaver 33 and the deinterleaver 44 are reduced, and a reduction in circuit scale can be expected.

(Modification 1)
Next, Modification 1 in which a part of the configurations of the wireless communication system 100 according to the first embodiment and the wireless communication system 101 according to the second embodiment is changed will be described. In the first modification, the frequency offset assigning means 14_1 to 14_M in the first embodiment or the frequency offset assigning means 34_1 to 34_M in the second embodiment is the absolute value of the difference between the frequency offsets given by different frequency offset giving means. Is configured so as to give a frequency offset so as to be different in all combinations. In the following, the frequency offset assigning means 14_1 to 14_M will be described with reference to FIG. 1, but the operations of the frequency offset giving means 14_1 to 14_M and the frequency offset giving means 34_1 to 34_M are the same. Similar effects can be obtained in the configuration.

  As described above, when the average quality of the short section of the input information sequence S25 is constant, the error correction code has a higher correction capability as the quality variation is smaller. Therefore, in order to obtain a high error correction effect and consequently a high diversity effect, it is required not only to keep the average quality of the short section constant but also to reduce the variation in the reception quality.

  The reception quality of the information sequence S25 is determined by the reception level of the signal S21 at the reception antenna 21. Therefore, as an index for estimating the diversity effect, the variance of the reception level fluctuation p (t) in the reception antenna 21 is used, and the difference in the diversity effect due to the difference in the frequency offset applying method will be described. Hereinafter, a case where the number of transmission antennas is three will be described, but the same effect can be obtained regardless of the number of transmission antennas.

  First, as shown in FIG. 2, a case is considered in which frequency offsets are regularly given at Δf intervals in the frequency offset giving means 14_1 to 14_M. At this time, the transmission antenna 16_1 is given a frequency offset of 0, the transmission antenna 16_2 is Δf, and the transmission antenna 16_3 is 2Δf, and the reception level fluctuation p (t) at the reception antenna 21 is expressed by the following equation ( 6).

  The variance of the reception level fluctuation p (t) at this time is expressed by the following equation (7).

  As is clear from the equation (7), when the frequency offset is regularly added, the dispersion of the reception level fluctuation has the phase dependence of the channel response, and depending on the phase relation of the channel response, the dispersion of the reception level fluctuation is very large. growing.

Next, as shown in FIG. 7, a case is considered in which the frequency offset is applied so that the absolute value of the frequency offset difference is different in all combinations in the frequency offset applying means 14_1 to 14_M. At this time, the transmission antenna 16_1 is given a frequency offset of 0, the transmission antenna 16_2 is Δf, and the transmission antenna 16_3 is 3Δf, and the reception level fluctuation p (t) is expressed by the following equation (8). Will be.

  The variance of the reception level fluctuation p (t) at this time is expressed by the following equation (9).

  As is apparent from Equation (9), when the frequency offset is applied so that the absolute value of the difference in frequency offset is different in all combinations, the channel response is not dependent on the dispersion of the reception level variation because the channel response has no phase dependence. Regardless of the phase relationship, the variance of the reception level fluctuation is always constant.

  As described above, when the frequency offset is applied so as to be different in all combinations of the absolute values of the frequency offset differences, the dispersion of the reception level fluctuation does not have the phase dependence of the channel response. A stable diversity effect can be obtained regardless of the relationship.

(Modification 2)
Next, Modification 2 in which a part of the configurations of the wireless communication system 100 according to the first embodiment and the wireless communication system 101 according to the second embodiment is changed will be described. In the second modification, when there is a large difference in the distance between the transmitting antennas in the first or second embodiment, the frequency offset applying means 14_1 to 14_M in the first embodiment or the frequency offset providing means in the second embodiment. In 34_1-34_M, the frequency offset provision means connected with a transmission antenna with a long distance is comprised so that the same frequency offset may be provided.

  Frequency offset transmission diversity gives a diversity effect by giving different frequency offsets to signals transmitted from multiple transmission antennas and forcibly generating fading, so antennas with the same frequency offset are given to each other The diversity effect cannot be obtained. However, when there is a large difference in the distance between transmitting antennas, there is a large difference in distance attenuation from transmitting antennas that are separated from each other, and the diversity effect by transmitting antennas that are close to each other is dominant. . For this reason, the decrease in the diversity effect due to the same frequency offset added to the signals transmitted from the transmitting antennas at a distance is negligible. On the other hand, if the frequency offset provided by the frequency offset assigning unit is too large, for example, when synchronous detection is used on the receiving side, reception quality deteriorates due to reasons such as being outside the pull-in range of AFC (Auto Frequency Control). Therefore, it is necessary not to increase the frequency offset types unnecessarily.

  From the above, when there is a large difference in the distance between the transmitting antennas, the frequency offset assigning means connected to the transmitting antennas that are separated from each other gives the same frequency offset, and the type of frequency offset is not increased unnecessarily. Thus, it is possible to reduce the maximum value of the frequency offset and reduce the inexpensive reception quality.

(Modification 3)
Next, Modification 3 in which a part of the configuration of the wireless communication system 100 according to the first embodiment and the wireless communication system 101 according to the second embodiment is changed will be described. In Modification 3, when there is a large difference in the distance between the transmitting antennas in the first or second embodiment, the frequency offset applying means 14_1 to 14_M in the first embodiment, or the frequency offset applying in the second embodiment. In the means 34_1 to 34_M, the frequency offset is given so that the absolute value of the difference between the frequency offsets given by the frequency offset giving means connected to the transmitting antennas close to each other becomes small.

  As described above, when the speed of fading fluctuation is high, the amount of phase change per symbol increases, and the reception quality deteriorates. Further, the phase change due to the non-dominant fading fluctuation can be ignored as compared with the phase change due to the dominant fading fluctuation. Therefore, it is required to reduce the speed of fading fluctuation that becomes particularly dominant.

  By the way, as described in the second modification, when there is a large difference in the distance between the transmission antennas, there is a large difference in distance attenuation from the transmission antennas that are separated from each other, and transmissions that are close to each other are performed. Diversity effect between antennas becomes dominant. Therefore, it is required to minimize the frequency offset added to the signal from the transmission antenna with a short distance. On the other hand, as described above, in the frequency offset transmission diversity method, since the diversity effect is obtained by giving different frequency offsets and forcibly generating fading, the diversity effect cannot be obtained if the same frequency is given. .

  From the above, when there is a large difference in the distance between the transmitting antennas, the absolute value of the difference in frequency offset provided by the frequency offset assigning means connected to the transmitting antenna that is close to the distance becomes a value that is as small as zero. It can be seen that by giving a frequency offset to, it is possible to slow down the dominant fading speed and reduce the degradation of reception quality.

(Modification 4)
Next, Modification 4 in which a part of the configuration of the wireless communication system 100 according to the first embodiment and the wireless communication system 101 according to the second embodiment is changed will be described. In the modification 4, the operations of the interleaver 12 and the deinterleaver 25 in the first embodiment, or the interleaver 33 and the deinterleaver 44 in the second embodiment are different from those in the first and second embodiments.

  The deinterleaver 25 and the deinterleaver 44 differ only in whether deinterleaving is performed on bits or symbols, and their operation principles are the same. In the following, the operation of the deinterleaver 25 will be described. However, since the interleaver 12 and the deinterleaver 25 and the interleaver 33 and the deinterleaver 44 perform exactly the reverse operations, respectively, the deinterleaver 25 and the first The same effect can be obtained even when applied to the interleaver 33 and the deinterleaver 44 of the second embodiment.

  In the operation of the deinterleaver 25 in the first embodiment, “L bits arranged at q × k × fs / Δf / L bit intervals of the information sequence S24 input to the deinterleaver 25 are output from the deinterleaver 25. The information sequence S25 is arranged in an arbitrary order in consecutive L bits ”. In the operation of the deinterleaver 25 in the modified example 4, “L is a power of 2 and any power of 2 that is not less than 2 and not more than L is defined as r. The constraint is that r bits arranged at q × k × fs / Δf / r bit intervals of the input information sequence S24 are continuous in the information sequence S25 output from the deinterleaver 25 ”.

  By imposing such constraint conditions, if r ′ is a power of 2 greater than or equal to q × (N + 1), the average reception quality of consecutive r ′ bits of the information sequence S25 is arbitrary for any r ′. It becomes constant. This is because the L bits arranged at q × k × fs / Δf / L bit intervals of the information sequence S24 input to the deinterleaver 25 for any L greater than or equal to q × (N + 1) are deinterleaver. When the bits are rearranged so that they are arranged in an arbitrary order in consecutive L bits in the information sequence S25 output from 25, it is clear that the average reception quality of consecutive L bits becomes constant. .

  By the way, as described above, when the deinterleaver 25 according to the first embodiment is used, if L is equal to or greater than q × (N + 1), the average reception quality of consecutive L bits of the information sequence S25 becomes constant. . As a result, when the value of N changes depending on the situation, for example, even when the number of transmission antennas changes, the structure of the deinterleaver 25 can be changed by setting L so that it can handle the maximum possible N. And high diversity effect can be obtained.

  However, conversely, if L is set to a large value, even if N is small, there is no guarantee that the average reception quality will be constant unless L bits are always collected. Is shown. In addition, error correction capability of an error correction code decreases when reception quality fluctuates in a cycle longer than its constraint length or block length. From the above, if L is set to a large value compared to the constraint length or block length of the error correction code in order to cope with a large N, the period L at which the reception quality becomes constant becomes long and the value of N is small. In this case, for example, it is understood that there is a risk that the error correction capability is always reduced even when the number of transmission antennas is small.

  On the other hand, when the deinterleaver 25 in the fourth modification is used, the average reception quality of consecutive r ′ bits of the information sequence S25 can be made constant at an arbitrary r ′. Here, r ′ is a value that depends only on N, and a value that does not depend on L. Therefore, even if L is set to a large value in order to cope with a large N, when the value of N is small, for example, when the number of transmission antennas is small, it is possible to suppress a decrease in diversity effect due to a decrease in error correction capability. it can.

The deinterleaver 25 in the modification 4 includes the matrix memory of L rows q × k × fs / Δf / L columns described above, writes data in the matrix memory in an arbitrary order, and in the row direction in an arbitrary order. Using a matrix interleaver that reads out, the following configuration can be made. That is, the number of rows L of the matrix memory is a power of 2, and the number l ′ of the row written to the matrix memory in the l-th (l is 0 to L−1) is l is a binary number of log ₂ (L) bits. Can be realized by a value obtained by reversing the order of the bits when displayed in the above, that is, a matrix interleaver (hereinafter referred to as a special matrix interleaver) given by the following equation (10).

  In Expression (10), and (x, y) is a function that returns a result obtained by ANDing two integers x and y for each bit.

  FIG. 8 shows an example of the configuration of the special matrix interleaver when fs / Δf = 32, L ′ = 4, q = 1, and k = 1. Hereinafter, it will be described with reference to FIG. 8 that the average reception quality of consecutive r ′ bits of the information sequence S25 is constant for an arbitrary r ′ by using a special matrix interleaver.

In the special matrix interleaver, the row number l ′ to be written in the matrix memory is a value obtained by reversing the order of bits when l is represented by a binary number of log ₂ (L) bits. Only the upper log ₂ (r) bits are different in the writing order to the r row, and the same r values are arranged in the lower log ₂ (L) −log ₂ (r) bits. If a matrix interleaver is used, 2 bits of the same column written in the 1st and 1 + 1th columns in the matrix memory become 2 bits apart from q × fs / Δf / L of the information sequence S24. As described above, the continuous r bits of the information sequence S25 after reading in the row direction are (L / r) × (q × fs / Δf / L) = q × k × fs / Δf / r bit interval of the information sequence S24. It can be seen that when r is q × (N + 1) or more, the average reception quality is constant.

  FIG. 10 shows a scheme in which the special matrix interleaver shown in FIG. 8 is applied to the wireless communication system 100 according to the first embodiment under the conditions shown in FIG. 9 (hereinafter, “Scheme B” in the text and FIGS. 9 and 10). The simulation result about the SNR vs. BLER characteristic is described. For comparison, the case where the simple matrix interleaver shown in FIG. 3 is provided to the wireless communication system 100 according to the first embodiment (“method A” described above) was also simulated under the conditions shown in FIG. The results are also shown.

As is clear from FIG. 10, in the scheme (“Scheme B”) in which the special matrix interleaver is applied to the wireless communication system 100 according to the first embodiment, even when L is set larger than the constraint length of the error correction code, N It can be seen that a high diversity effect can be obtained when is small, that is, when the number of transmission antennas is small.

  In the wireless communication system that realizes the frequency offset transmission diversity scheme according to the first and second embodiments and the first to fourth modifications, the frequency difference between the frequency offsets is an integer multiple of Δf excluding 0. By giving the offset, the average reception level at every time T = 1 / Δf, that is, the average reception quality, is made constant regardless of the maximum value of the difference between the number of transmission antennas and the frequency offsets to be given. As a result, it is possible to design an interleaver and deinterleaver that realizes flexibility with respect to a high diversity effect and a change in the number of antennas.

  Further, q is an arbitrary natural number, k is a modulation multi-value number, fs is a symbol rate, N is a value obtained by dividing the maximum difference between frequency offsets to be given by Δf, and an arbitrary natural number of q × (N + 1) or more. When L is set, L bits arranged at an interval of q × k × fs / Δf / L bit of the information sequence input to the deinterleaver are arbitrarily set to L bits continuous in the information sequence output from the deinterleaver. By rearranging the bits so that they are arranged in order, the average of consecutive L bits of the information sequence output from the deinterleaver is independent of the maximum number of differences between the number of antennas and the frequency offset to be applied. The reception quality is constant. As a result, the error correction capability of the decoding means can be utilized to the maximum, and as a result, a high diversity effect and flexibility in changing the number of antennas can be obtained.

1 is a block diagram schematically showing a wireless communication system according to a first embodiment of the present invention. It is the figure which showed an example of operation | movement of the frequency offset provision means which concerns on 1st Embodiment. It is a figure which shows an example of a structure and operation | movement of a deinterleaver implement | achieved by the simple matrix interleaver which concerns on 1st Embodiment. It is the figure which showed the simulation conditions of the SNR vs. BLER characteristic with respect to the radio | wireless communications system which concerns on 1st Embodiment. It is the figure which showed the simulation result of the SNR vs. BLER characteristic in the structure of the radio | wireless communications system which concerns on 1st Embodiment, and the structure when a simple matrix interleaver is not applied by the said structure. It is the block diagram which showed schematically the radio | wireless communications system which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of operation | movement of the frequency offset provision means which concerns on the modification 1 of this invention. It is a figure which shows an example of a structure and operation | movement of a deinterleaver implement | achieved by the special matrix interleaver which concerns on the modification 4 of this invention. 10 is a diagram showing simulation conditions for SNR vs. BLER characteristics for a wireless communication system according to Modification 4. FIG. It is the figure which showed the simulation result of the SNR vs. BLER characteristic in the structure of the radio | wireless communications system which concerns on the modification 4, and the structure when a simple matrix interleaver is not applied by the said structure. It is the block diagram which showed schematically the radio | wireless communications system to which the conventional frequency offset transmission diversity system is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Radio | wireless communications system 1 Transmission apparatus 11 Encoding means 12 Interleaver 13 Symbol generation means 14_1-14_M Frequency offset provision means 15_1-15_M Radio | wireless part 16_1-16_M Transmission antenna 2 Reception apparatus 21 Reception antenna 22 Radio | wireless part 23 Detection means 24 Symbol identification means 25 Deinterleaver 26 Decoding unit 101 Wireless communication system 3 Transmitting unit 31 Encoding unit 32 Symbol generating unit 33 Interleaver 34_1 to 34_M Frequency offset adding unit 35_1 to 35_M Radio unit 36_1 to 36_M Transmit antenna 4 Receiver 41 Receiver antenna 42 Radio unit 43 Detection means 44 Deinterleaver 45 Symbol identification means 46 Decoding means

Claims (31)

A wireless communication system comprising a transmission device having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception device for receiving a radio signal from the transmission device through a reception antenna,
The transmitter is
Encoding means for performing error correction encoding on an input information sequence;
An interleaver for interleaving the information sequence encoded by the encoding means;
Symbol generating means for converting the information sequence interleaved by the interleaver into a symbol sequence;
The difference between all the frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the symbol sequence converted by the symbol generating means is an integer multiple of the predetermined frequency Δf excluding 0. A plurality of frequency offset giving means for giving a frequency offset to the plurality of symbol sequences;
Transmitting means for transmitting the symbol sequence to which the frequency offset is given by the frequency offset giving means through the transmission antenna;
The receiving device is:
Receiving means for receiving a radio signal from the transmitting device through the receiving antenna;
Detecting means for detecting a signal received by the receiving means and converting it into a symbol sequence;
Symbol identifying means for converting the symbol series converted by the detecting means into an information series;
A deinterleaver for deinterleaving the information sequence converted by the symbol identification means;
A wireless communication system comprising: decoding means for performing error correction decoding on the information sequence deinterleaved by the deinterleaver. A wireless communication system comprising a transmission device having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception device for receiving a radio signal from the transmission device through a reception antenna,
The transmitter is
Encoding means for performing error correction encoding on an input information sequence;
Symbol generating means for converting the information sequence encoded by the encoding means into a symbol sequence;
An interleaver for interleaving the symbol sequence converted by the symbol generating means;
The difference between all frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the symbol sequence interleaved by the interleaver is an integral multiple of the predetermined frequency Δf excluding 0. A plurality of frequency offset applying means for applying a frequency offset to the plurality of symbol sequences;
Transmitting means for transmitting the symbol sequence to which the frequency offset is given by the frequency offset giving means through the transmission antenna;
The receiving device is:
Receiving means for receiving a radio signal from the transmitting device through the receiving antenna;
Detecting means for detecting a signal received by the receiving means and converting it into a symbol sequence;
A deinterleaver for deinterleaving the symbol sequence converted by the detection means;
Symbol identifying means for converting a symbol sequence deinterleaved by the deinterleaver into an information sequence;
A wireless communication system comprising: decoding means for performing error correction decoding on the information sequence converted by the symbol identification means. The plurality of frequency offset applying means includes
The radio communication system according to claim 1 or 2, wherein the frequency offset is given so that all the frequency offsets to be given are arranged at equal intervals. The frequency offset applying means is
The frequency offset is given so that the absolute value of the difference between two frequency offsets selected from all the frequency offsets to be given becomes a different value in a combination of all two frequency offsets. Or the radio | wireless communications system of 2. Arbitrary natural number q, modulation multi-value number k, symbol rate fs, maximum value of difference between frequency offsets provided by the plurality of frequency offset assigning means divided by Δf, N, q × (N + 1) When the above arbitrary natural number is L,
The interleaver is
Reordering the bits so that consecutive L bits of the input information sequence are arranged in an arbitrary order of q × k × fs / Δf / L bit interval in the output information sequence;
The deinterleaver is
Bit rearrangement is performed so that L bits arranged at q × k × fs / Δf / L bit intervals of an input information sequence are arranged in an arbitrary order in consecutive L bits in the output information sequence. The wireless communication system according to claim 1. Arbitrary natural number q, symbol rate fs, maximum difference between frequency offsets given by the plurality of frequency offset assigning means divided by Δf is N, and any natural number greater than q × (N + 1) is L If
The interleaver is
Rearranging symbols so that consecutive L symbols of the input symbol series are arranged in an arbitrary order of q × fs / Δf / L symbol intervals in the output symbol series;
The deinterleaver is
Symbol rearrangement is performed such that L symbols arranged at q × fs / Δf / L symbol intervals of an input symbol sequence are arranged in an arbitrary order in consecutive L symbols in the output information sequence. The wireless communication system according to claim 2, wherein: When L is a power of 2 and any power of 2 between 2 and L is r,
The interleaver is
For all possible r, the bits are rearranged so that consecutive r bits of the input information sequence are arranged at intervals of q × k × fs / Δf / r bits in the output information sequence,
The deinterleaver is
For all possible r's, the bits are rearranged so that r bits arranged at q × k × fs / Δf / r bit intervals of the input information sequence are continuous in the output information sequence. The wireless communication system according to claim 5. When L is a power of 2 and any power of 2 between 2 and L is r,
The interleaver is
For all possible r, the symbols are rearranged so that consecutive r symbols of the input symbol sequence are arranged at intervals of q × k × fs / Δf / r symbols in the output symbol sequence,
The deinterleaver is
For all possible r, the symbols are rearranged so that r symbols arranged at q × k × fs / Δf / r symbol intervals of the input symbol series are continuous in the output symbol series. The wireless communication system according to claim 6. The interleaver is
A matrix interleaver having a matrix memory of L rows q × k × fs / Δf / L columns, writing to the matrix memory in the column direction in an arbitrary order, and reading in the row direction in an arbitrary order;
The deinterleaver is
A matrix deinterleaver having a matrix memory of L rows q × k × fs / Δf / L columns, writing to the matrix memory in the row direction in any order, and reading in the column direction in any order The wireless communication system according to claim 5. The interleaver is
A matrix interleaver having a matrix memory of L rows q × fs / Δf / L columns, writing to the matrix memory in the column direction in an arbitrary order, and reading in the row direction in an arbitrary order;
The deinterleaver is
A matrix deinterleaver having a matrix memory of L rows q × fs / Δf / L columns, writing to the matrix memory in the row direction in any order, and reading in the column direction in any order The wireless communication system according to claim 6. The interleaver is
A row number to be written to the matrix memory and a column number to be read from the matrix memory are given in ascending order;
The deinterleaver is
The wireless communication system according to claim 9 or 10, wherein a row number to be written in the matrix memory and a column number to be read from the matrix memory are given in ascending order. The interleaver is
The row number L of the matrix memory is a power of 2;
The number l ′ of the row written to the l-th (l is 0 to L−1) in the matrix memory is given as a value obtained by reversing the order of bits when l is represented by a binary number of log ₂ (L) bits. And
The deinterleaver is
The row number L of the matrix memory is a power of 2;
The number l ′ of the row written to the l-th (l is 0 to L−1) in the matrix memory is given as a value obtained by reversing the order of bits when l is represented by a binary number of log ₂ (L) bits. The wireless communication system according to claim 9, wherein: The interleaver is
The row number L of the matrix memory is a power of 2;
The number l ′ of the row written to the l-th (l is 0 to L−1) in the matrix memory is given as a value obtained by reversing the arrangement of the symbols when l is displayed as a binary number of log ₂ (L) symbols. And
The deinterleaver is
The row number L of the matrix memory is a power of 2;
The number l ′ of the row written to the l-th (l is 0 to L−1) in the matrix memory is given as a value obtained by reversing the arrangement of the symbols when l is displayed as a binary number of log ₂ (L) symbols. The wireless communication system according to claim 10, wherein: A communication method performed by a transmission device having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception device receiving a radio signal from the transmission device through a reception antenna,
In the transmission device,
An error correction encoding of an input information sequence;
Interleaving the encoded information sequence;
Converting the interleaved information sequence into a symbol sequence;
The plurality of frequency offsets so that the difference between all the frequency offsets assigned to each of the plurality of symbol sequences obtained by branching the converted symbol sequence is an integer multiple excluding 0 of the predetermined frequency Δf. Applying a frequency offset to the symbol sequence;
Transmitting the symbol sequence to which the frequency offset is added through the transmission antenna,
In the receiving device,
Receiving a radio signal from the transmitting device through the receiving antenna;
Detecting the received signal and converting it to a symbol sequence;
Converting the converted symbol sequence into an information sequence;
Deinterleaving the transformed information sequence;
Error correcting decoding the deinterleaved information sequence;
A communication method comprising: A communication method performed by a transmission device having a plurality of transmission antennas and transmitting by a frequency offset transmission diversity method, and a reception device receiving a radio signal from the transmission device through a reception antenna,
In the transmission device,
An error correction encoding of an input information sequence;
Converting the encoded information sequence into a symbol sequence;
Interleaving the transformed symbol sequence;
The plurality of frequency offsets so that a difference between all the frequency offsets assigned to each of the plurality of symbol sequences obtained by branching the interleaved symbol sequence is an integer multiple excluding 0 of a predetermined frequency Δf. Applying a frequency offset to the symbol sequence;
Transmitting the symbol sequence to which the frequency offset is added through the transmission antenna, and in the receiving apparatus,
Receiving a radio signal from the transmitting device through the receiving antenna;
Detecting the received signal and converting it to a symbol sequence;
Deinterleaving the detected symbol sequence;
Converting the deinterleaved symbol sequence to an information sequence;
Performing error correction decoding on the converted information sequence;
A communication method comprising: In the step of providing the frequency offset,
The communication method according to claim 14 or 15, wherein the frequency offset is given so that all the frequency offsets to be given are arranged at equal intervals. In the step of providing the frequency offset,
The frequency offset is given so that the absolute value of the difference between two frequency offsets selected from all the frequency offsets to be given becomes a different value in the combination of all two frequency offsets. Or the communication method of 15. Arbitrary natural number q, modulation multi-value number k, symbol rate fs, maximum value of difference between frequency offsets provided by the plurality of frequency offset assigning means divided by Δf, N, q × (N + 1) When the above arbitrary natural number is L,
In the interleaving step,
Reordering the bits so that consecutive L bits of the input information sequence are arranged in an arbitrary order of q × k × fs / Δf / L bit interval in the output information sequence;
In the deinterleaving step,
Bit rearrangement is performed so that L bits arranged at q × k × fs / Δf / L bit intervals of an input information sequence are arranged in an arbitrary order in consecutive L bits in the output information sequence. The communication method according to claim 14. Arbitrary natural number q, symbol rate fs, maximum difference between frequency offsets given by the plurality of frequency offset assigning means divided by Δf is N, and any natural number greater than q × (N + 1) is L If
In the interleaving step,
Rearranging symbols so that consecutive L symbols of the input symbol series are arranged in an arbitrary order of q × fs / Δf / L symbol intervals in the output symbol series;
In the deinterleaving step,
Symbol rearrangement is performed such that L symbols arranged at q × fs / Δf / L symbol intervals of an input symbol sequence are arranged in an arbitrary order in consecutive L symbols in the output information sequence. The communication method according to claim 15, wherein: A transmission apparatus having a plurality of transmission antennas and performing transmission by a frequency offset transmission diversity method,
Encoding means for performing error correction encoding on an input information sequence;
An interleaver for interleaving the information sequence encoded by the encoding means;
Symbol generating means for converting the information sequence interleaved by the interleaver into a symbol sequence;
The difference between all the frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the symbol sequence converted by the symbol generating means is an integer multiple of the predetermined frequency Δf excluding 0. A plurality of frequency offset giving means for giving a frequency offset to the plurality of symbol sequences;
A transmission apparatus comprising: a transmission unit configured to transmit the symbol sequence to which the frequency offset is added by the frequency offset addition unit through the transmission antenna. A transmission apparatus having a plurality of transmission antennas and performing transmission by a frequency offset transmission diversity method,
Encoding means for performing error correction encoding on an input information sequence;
Symbol generating means for converting the information sequence encoded by the encoding means into a symbol sequence;
An interleaver for interleaving the symbol sequence converted by the symbol generating means;
The difference between all frequency offsets assigned to each of a plurality of symbol sequences obtained by branching the symbol sequence interleaved by the interleaver is an integral multiple of the predetermined frequency Δf excluding 0. A plurality of frequency offset applying means for applying a frequency offset to the plurality of symbol sequences;
A transmission device comprising: a transmission unit configured to transmit the symbol sequence to which the frequency offset is added by the frequency offset addition unit through the transmission antenna. The plurality of frequency offset applying means includes
The transmission apparatus according to claim 20 or 21, wherein the frequency offset is applied so that all the applied frequency offsets are arranged at equal intervals. The frequency offset applying means is
21. The frequency offset is given so that an absolute value of a difference between two frequency offsets selected from all the frequency offsets to be given becomes a different value in a combination of all two frequency offsets. Or the transmission apparatus of 21. Arbitrary natural number q, modulation multi-value number k, symbol rate fs, maximum value of difference between frequency offsets provided by the plurality of frequency offset assigning means divided by Δf, N, q × (N + 1) When the above arbitrary natural number is L,
The interleaver is
The bit rearrangement is performed such that consecutive L bits of an input information sequence are arranged in an arbitrary order of q × k × fs / Δf / L bit intervals in an output information sequence. Item 20. The transmitter according to Item 20. Arbitrary natural number q, symbol rate fs, maximum difference between frequency offsets given by the plurality of frequency offset assigning means divided by Δf is N, and any natural number greater than q × (N + 1) is L If
The interleaver is
The symbol rearrangement is performed such that consecutive L symbols of the input symbol series are arranged in an arbitrary order of q × fs / Δf / L symbol intervals in the output symbol series. The transmitting device described. A transmission method in a transmission apparatus having a plurality of transmission antennas and performing transmission in a frequency offset transmission diversity system,
An error correction encoding of an input information sequence;
Interleaving the encoded information sequence;
Converting the interleaved information sequence into a symbol sequence;
The plurality of frequency offsets so that the difference between all the frequency offsets assigned to each of the plurality of symbol sequences obtained by branching the converted symbol sequence is an integer multiple excluding 0 of the predetermined frequency Δf. Applying a frequency offset to the symbol sequence;
Transmitting the symbol sequence to which the frequency offset is assigned through the transmission antenna;
The transmission method characterized by including. A transmission method in a transmission apparatus having a plurality of transmission antennas and performing transmission by a frequency offset transmission diversity method,
An error correction encoding of an input information sequence;
Converting the encoded information sequence into a symbol sequence;
Interleaving the transformed symbol sequence;
The plurality of frequency offsets so that a difference between all the frequency offsets assigned to each of the plurality of symbol sequences obtained by branching the interleaved symbol sequence is an integer multiple excluding 0 of a predetermined frequency Δf. Applying a frequency offset to the symbol sequence;
Transmitting the symbol sequence to which the frequency offset is added through the transmission antenna. In the step of providing the frequency offset,
The transmission method according to claim 26 or 27, wherein the frequency offset is given so that all the frequency offsets to be given are arranged at equal intervals. In the step of providing the frequency offset,
27. The frequency offset is given so that an absolute value of a difference between two frequency offsets selected from all the frequency offsets to be given becomes a different value in a combination of all two frequency offsets. Or the transmission method of 27. Arbitrary natural number q, modulation multi-value number k, symbol rate fs, maximum value of difference between frequency offsets provided by the plurality of frequency offset assigning means divided by Δf, N, q × (N + 1) When the above arbitrary natural number is L,
In the interleaving step,
The bit rearrangement is performed such that consecutive L bits of an input information sequence are arranged in an arbitrary order of q × k × fs / Δf / L bit intervals in an output information sequence. Item 27. The transmission method according to Item 26. Arbitrary natural number q, symbol rate fs, maximum difference between frequency offsets given by the plurality of frequency offset assigning means divided by Δf is N, and any natural number greater than q × (N + 1) is L If
In the interleaving step,
The symbol rearrangement is performed so that consecutive L symbols of the input symbol series are arranged in an arbitrary order of q × fs / Δf / L symbol intervals in the output symbol series. The communication method described.

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