JP2006060870A - Modulation method and wireless communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a data transmission amount from being reduced by having roles of data transmission as well as a pilot symbol in a digital modulation scheme used in wireless communication and a wireless communication system using the same. <P>SOLUTION: A PSK modulation method is periodically inserted into an octonary or more multi-level modulation method, and data are transmitted in the PSK modulation scheme and at the same time, a frequency offset amount and an amplitude distortion amount between a transmitter and a receiver are estimated at a demodulation side by an amplitude distortion amount estimation part 25 and a frequency offset amount estimation part 26 respectively, thereby the data transmission amount is suppressed from being reduced in comparison with a scheme wherein known data are used as a pilot symbol. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital modulation method used for wireless communication and a transmission apparatus using the same.

Conventionally, there has been known a method related to a pilot symbol when performing quasi-synchronous detection in a digital mobile radio communication system (see, for example, Patent Document 1). FIG. 26 shows a conventional frame structure of a signal to be transmitted. In FIG. 26, one frame is composed of N symbols, and two pilot symbols composed of known data are inserted at the head of the frame. Followed by (N-2) information symbols, which are repeated for each frame in the transmitted signal.
JP-A-9-93302

  However, the conventional method has a drawback in that the amount of data transmission is reduced because pilot symbols are known data.

  The present invention inserts a PSK modulation system periodically into a multi-level modulation system of 8 or more values, transmits data using PSK modulation symbols, and simultaneously serves as a pilot symbol, thereby increasing the amount of data transmission. The purpose is to suppress the decrease of the.

  In order to solve this problem, the present invention inserts a PSK modulation system periodically into a multi-level modulation system of 8 or more values, and differentially encodes between PSK modulation system symbols to transmit data. At the same time, quasi-synchronous detection is performed by using pilot symbols for estimating the frequency offset amount and amplitude distortion amount between the transmitter and the receiver on the demodulation side.

  Thereby, since data is transmitted by the PSK modulation method, it is possible to suppress a decrease in the amount of data transmission compared to a method using known data as a pilot symbol.

  As described above, according to the present invention, PSK modulation is performed by periodically inserting a PSK modulation scheme into a multi-level modulation scheme of 8 or more values and differentially encoding between symbols of the PSK modulation scheme. By performing quasi-synchronous detection as a pilot symbol for estimating the frequency offset amount and amplitude distortion amount between the transmitter and receiver on the demodulation side at the same time as transmitting data in the method, compared with a method using known data as a pilot symbol, An advantageous effect that a decrease in the amount of data transmission can be suppressed is obtained.

The present invention is used for wireless communication, and a first modulation scheme, a multilevel orthogonal modulation scheme (multilevel QAM; Quadrature Amplitude Modulation), is regularly added to a second modulation scheme, phase modulation (P
SK (Phase Shift Keying) method is a modulation method in which a pilot signal is inserted, and information is added to the signal of the second modulation method, and the amplitude and phase distortion amount of the signal of the first modulation method are A modulation scheme characterized in that it is obtained directly using the pilot signal, and in the PSK modulation scheme, pilot symbols for estimating the frequency offset amount and the amplitude distortion amount between the transmitter and the receiver on the demodulation side at the same time as transmitting data Thus, by performing quasi-synchronous detection, it is possible to suppress a decrease in the amount of data transmission compared to a method using known data as a pilot symbol.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a conceptual diagram of a configuration of a radio communication system according to the present embodiment. In FIG. 1, 10 is a transmitter, 11 is a transmission digital signal, and 12 is a quadrature baseband modulation unit, which inputs the transmission digital signal 11 and outputs an in-phase component 13 and a quadrature component 14 of the transmission quadrature baseband signal. The in-phase component 13 and the quadrature component 14 are converted into a transmission signal 16 by the transmission radio unit 15 and transmitted from the antenna 17. Reference numeral 20 denotes a receiver, 21 denotes an antenna, and 22 denotes a reception radio unit, which inputs a signal received by the antenna and outputs an in-phase component 23 and a quadrature component 24 of the received quadrature baseband signal. An amplitude distortion amount estimation unit 25 receives the in-phase component 23 and the quadrature component 24, estimates the amplitude distortion amount, and outputs an amplitude distortion amount estimation signal 27. A frequency offset amount estimation unit 26 receives the in-phase component 23 and the quadrature component 24, estimates the frequency offset amount, and outputs a frequency offset amount estimation signal 28. A quasi-synchronous detection unit 29 receives the in-phase component 23 and the quadrature component 24, the amplitude distortion amount estimation signal 27 and the frequency offset amount estimation signal 28, performs quasi-synchronization detection, and outputs a received digital signal.

  FIG. 2 shows signal point arrangements in the in-phase I-orthogonal Q plane of the 8-phase PSK modulation system, which is an example of a multi-level modulation system with 8 levels or more. In FIG. is there. FIG. 3 shows a signal point arrangement on the in-phase I-orthogonal Q plane of the binary phase modulation (BPSK: Binary Phase Shift Keying) system which is an example of the PSK modulation system. In FIG. 3, reference numeral 201 denotes a signal point of the BPSK modulation system. It is. FIG. 4 shows an example of a configuration in N symbols of an 8-phase PSK modulation symbol and a BPSK modulation symbol. FIG. 5 shows an example of information sequence arrangement of signal points of the BPSK modulation method when differential encoding is performed. 6 (a) and 6 (b) are examples of the relationship between the signal points of the immediately preceding BPSK modulation symbol and the signal points of the 8-phase PSK modulation system, and in FIG. 6, reference numeral 501 denotes the signal point of the BPSK modulation system, Reference numeral 502 denotes an 8-phase PSK modulation signal point.

  1 to 6, in a modulation scheme in which a PSK modulation scheme is periodically inserted into a multi-level modulation scheme of 8 or more values, differential encoding is performed between PSK modulation symbols, and a multi-level of 8 or more values is obtained. A modulation scheme in which an information sequence of modulation scheme signal points is arranged based on the signal point position of the immediately preceding PSK modulation symbol will be described.

  FIG. 2 shows the arrangement of signal points 101 of the 8-phase PSK modulation system in the in-phase I-orthogonal Q plane, and the arrangement position of the signal points 101 is expressed by (Equation 1). However, the signal point 101 of the 8-phase PSK modulation system is represented by (I8PSK, Q8PSK), k is an integer, and p is a constant.

  FIG. 3 shows the arrangement of signal points 201 of the BPSK modulation method in the in-phase I-orthogonal Q plane, and the arrangement positions of the signal points 201 are expressed by (Equation 2). However, the signal point 201 of the BPSK modulation method is represented by (IBPSK, QBPSK), k is an integer, and r is a constant.

  FIG. 4 shows an example of the configuration of 8-phase PSK modulation symbols and BPSK modulation symbols in N symbols. At this time, if the phase in the in-phase I-quadrature Q plane of the i-th BPSK modulation symbol is φi and the phase in the in-phase I-quadrature Q-plane of the i + N-th BPSK modulation symbol is φi + N, the i + N-th in the xy plane If the phase θi + N is (Equation 3), the information sequence can be determined by θi + N as shown in FIG.

  FIG. 6 shows an example of the relationship between the information sequence of the signal point 501 of the immediately preceding BPSK modulation symbol and the signal point 502 of the 8-phase PSK modulation system. The information sequence of the signal point 501 of the i-th BPSK modulation symbol and the signal point 502 of the (i + 1) to (i + 1) to (i + N-1) -th 8-phase PSK modulation symbol is the previous BPSK modulation symbol as shown in FIG. The signal sequence of the signal points of the 8-phase PSK modulation symbol is determined by the signal points.

  In this way, data is transmitted in the 8-phase PSK modulation method, and data is transmitted in the BPSK modulation method. At the same time, the demodulation side estimates the frequency offset amount and amplitude distortion amount between the transmitter and the receiver as pilot symbols, and performs quasi-synchronous detection. . Here, the configuration of the 8-phase PSK modulation symbol and the BPSK modulation symbol in the N symbols is not limited to that shown in FIG. Further, although an 8-phase PSK modulation system has been described as an example of an 8-level or more multi-level modulation system, the 8-level or more multi-level modulation system is not limited to this, and an example of a PSK modulation system is a BPSK modulation system. As described above, the PSK modulation method is not limited to this.

  As described above, according to the present embodiment, a PSK modulation system is periodically inserted into an 8-level or higher multi-level modulation system, differential encoding is performed between PSK modulation symbols, and a multi-level of 8 or higher levels. A modulation scheme in which an information sequence of modulation scheme signal points is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol. In the PSK modulation scheme, the frequency offset amount and amplitude distortion between the transmitter and the receiver are transmitted at the same time as data is transmitted. By using pilot symbols for estimating the amount of data, the amount of data transmission can be reduced without reducing the amount of data transmission compared to a method using known data as pilot symbols to estimate the amount of frequency offset and amplitude distortion between transmitters and receivers. Synchronous detection can be performed.

  In the present embodiment, a system is described in which differential encoding is performed between PSK modulation symbols, and an information sequence of signal points of a multi-level modulation system of 8 or more values is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol. However, the same effect can be obtained by inserting PSK modulation symbols that are differentially encoded between PSK modulation symbols.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 2)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

7 shows a signal point arrangement in the phase I- quadrature Q plane 2 ^2m-QAM scheme, which is an example of a multi-level QAM system than 8 values, 7, 601 denotes a signal point of 2 ^2m-QAM scheme is there. Further, the signal point arrangement in the in-phase I-orthogonal Q plane of the BPSK modulation method which is an example of the PSK modulation method is the same as that in FIG. 3 of the first embodiment. FIG. 8 shows a signal point arrangement in the in-phase I-quadrature Q plane of the 16QAM system. In FIG. 8, reference numeral 701 denotes a signal point of the 16QAM system. FIG. 9 shows an example of a configuration in N symbols of 16QAM symbols and BPSK modulation symbols. An example of the information sequence arrangement of signal points of the BPSK modulation method when differential encoding is performed is the same as that in FIG. 5 of the first embodiment. FIGS. 10A and 10B are examples of the relationship between the signal sequence of the immediately preceding BPSK modulation symbol and the information sequence of 16QAM signal points. In FIG. 10, 901 is the signal point of the BPSK modulation method, and 902 is 16QAM. Signal point of the system.

  1, 3, 5, and 7 to 10, in a modulation scheme in which a PSK modulation scheme is periodically inserted in a multi-level QAM scheme of 8 or more values, a difference is generated between PSK modulation symbols. Encodes and periodically inserts PSK modulation system into modulation system in which information sequence of multi-point QAM system signal point of 8 or more values is arranged with reference to signal point position of immediately preceding PSK modulation symbol, or 16QAM system In this modulation scheme, a modulation scheme in which PSK modulation symbols are differentially encoded and an information sequence of 16QAM signal points is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol will be described.

FIG. 7 shows the arrangement of 22 ^m- value QAM signal points 601 in the in-phase I-quadrature Q plane, and the arrangement position of the signal points 601 is expressed by (Equation 4). However, the signal point 401 of 2 ^2m-QAM scheme is represented by (IQAM, QQAM), m is an integer, (a1, b1), ( a2, b2), ···, (am, bm) is 1, -1 Binary code, r is a constant.

  FIG. 8 shows the arrangement of 16QAM signal points 701 in the in-phase I-quadrature Q plane, and the arrangement positions of the signal points 701 are expressed by (Equation 5). However, the signal point 701 of the 16QAM system is represented by (I16QAM, Q16QAM), (a1, b1), (a2, b2) are binary codes of 1, -1 and s is a constant.

  Further, the signal point arrangement of the BPSK modulation method is as shown in FIG. 3, and is the same as that described in the first embodiment.

  FIG. 9 shows an example of the configuration of 16QAM symbols and BPSK modulation symbols in N symbols. At this time, if the phase in the in-phase I-quadrature Q plane of the i-th BPSK modulation symbol is φi and the phase in the in-phase I-quadrature Q-plane of the i + N-th BPSK modulation symbol is φi + N, the i + N-th in the xy plane If the phase θi + N is (Equation 3), the information sequence can be determined by θi + N as shown in FIG.

  FIG. 10 shows an example of the relationship between the information sequence of the signal point 901 of the immediately preceding BPSK modulation symbol and the signal point 902 of the 16QAM system. The information series of the signal point 901 of the i-th BPSK modulation symbol and the signal point 902 of the (i + 1) to (i + 1) to (i + N-1) -th 16QAM symbol are expressed in two ways as shown in FIG. 10 (a) or FIG. 10 (b).

In this way, data transmission is performed in the 16QAM system, and data is transmitted in the BPSK modulation system. At the same time, the demodulation side estimates the frequency offset amount and amplitude distortion amount between the transmitter and the receiver as pilot symbols, and performs quasi-synchronous detection. Here, the configuration of 16QAM symbols and BPSK modulation symbols in N symbols is not limited to that shown in FIG. Although the 16QAM system has been described as an example, the same applies to the 2 ^2m- value QAM system. At this time, the multi-value QAM system of 8 or more values is not limited to the 2 ^2m- value QAM system. The BPSK modulation method has been described as an example of the PSK modulation method, but the PSK modulation method is not limited to this.

  As described above, according to the present embodiment, a PSK modulation scheme is periodically inserted into a multilevel QAM scheme of eight or more values, differential encoding is performed between PSK modulation symbols, and a multilevel of eight or more values is obtained. A modulation system in which an information sequence of QAM system signal points is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol, or a PSK modulation system is periodically inserted into the 16QAM system, and differential between PSK modulation symbols. This is a modulation method in which an information sequence of 16QAM signal points is encoded and arranged with reference to the signal point position of the immediately preceding PSK modulation symbol. In the PSK modulation method, the frequency offset amount between the transmitter and the receiver is transmitted at the same time as the data is transmitted. And pilot symbols for estimating the amplitude distortion amount, the known data is passed to estimate the frequency offset amount and amplitude distortion amount between the transmitter and the receiver. Compared to method of the lot symbols can be performed quasi-synchronized detection without reducing the amount of data transmission.

  In the present embodiment, a differential encoding is performed between PSK modulation symbols, and a multi-level QAM signal point information sequence of eight or more values is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol, or In the above description, the 16QAM signal point information sequence is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol. However, in any case, if a differentially encoded PSK modulation symbol is inserted between PSK modulation symbols, An effect is obtained.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 3)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

FIG. 11 shows an example of an 8-phase or higher multi-level QAM system obtained by rotating a signal point of 8-level or higher multi-level QAM system by π / 4 radians on the in-phase I-quadrature Q plane. The signal point arrangement in the in-phase I-orthogonal Q plane of the 2 ^2m value QAM system obtained by rotating the signal point of the ^2m value QAM system by π / 4 radians is shown. In FIG. 11, reference numeral 1001 denotes the signal point of the 2 ^2m value QAM system. is there. Further, the signal point arrangement in the in-phase I-orthogonal Q plane of the BPSK modulation method which is an example of the PSK modulation method is the same as that in FIG. 3 of the first embodiment. FIG. 12 shows a signal point arrangement on a 16QAM system in-phase I-quadrature Q plane obtained by rotating a 16QAM system signal point on the in-phase I-quadrature Q plane by π / 4 radians. In FIG. 12, reference numeral 1101 denotes the 16QAM system signal. Is a point. The configurations of the 16QAM symbols and BPSK modulation symbols in N symbols are the same as those in FIG. 9 of the second embodiment. An example of the information sequence arrangement of signal points of the BPSK modulation method when differential encoding is performed is the same as that in FIG. 5 of the first embodiment. FIGS. 13A and 13B show an example of the relationship between the signal point of the immediately preceding BPSK modulation symbol and the information sequence of the 16QAM signal point. In FIG. 13, 1201 is the signal point of the BPSK modulation method, 1202 This is a signal point of the 16QAM system.

  1, 3, 5, 9, and 11 to 13, in a modulation scheme in which a PSK modulation scheme is periodically inserted in the multilevel QAM scheme of 8 or more values, between PSK modulation symbols In the modulation scheme in which the information sequence of the signal points of the multi-level QAM scheme of 8 or more values is arranged based on the signal point position of the immediately preceding PSK modulation symbol, or the 16QAM scheme, is periodically encoded. In the modulation scheme in which the PSK modulation scheme is inserted, a modulation scheme in which differential encoding is performed between PSK modulation symbols and the information sequence of the 16QAM signal points is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol will be described.

FIG. 11 shows the arrangement of the signal point 1001 of the 22 ^m- value QAM system on the in-phase I-orthogonal Q plane, and the arrangement position of the signal point 1001 is expressed by (Equation 6). However, the signal point 1001 of the 2 ^2m value QAM system is represented by (IQAMR, QQAMR), (IQAM, QQAM) is represented by (Equation 4), and n is an integer.

  FIG. 12 shows the arrangement of the 16QAM signal points 1101 on the in-phase I-orthogonal Q plane, and the arrangement positions of the signal points 1101 are expressed by (Expression 7). However, the signal point 1101 of the 16QAM system is represented by (I16QAMR, Q16QAMR), (I16QAM, Q16QAM) is represented by (Equation 5), and n is an integer.

  Further, the signal point arrangement of the BPSK modulation method is as shown in FIG. 3, and is the same as that described in the first embodiment.

  FIG. 9 shows an example of the configuration of the 16QAM symbol and the BPSK modulation symbol in N symbols. At this time, if the phase in the in-phase I-quadrature Q plane of the i-th BPSK modulation symbol is φi and the phase in the in-phase I-quadrature Q-plane of the i + N-th BPSK modulation symbol is φi + N, the i + N-th in the xy plane If the phase θi + N is (Equation 3), the information sequence can be determined by θi + N as shown in FIG.

  FIG. 13 shows an example of the relationship between the information sequence of the signal point 1201 of the immediately preceding BPSK modulation symbol and the signal point 1202 of the 16QAM system. The information series of the signal point 1201 of the i-th BPSK modulation symbol and the signal point 1202 of the 16QAM symbol of the (i + 1) to (i + 1) to (i + N-1) -th are expressed in two ways as shown in FIG. 13 (a) or FIG. 13 (b).

In this way, data transmission is performed in the 16QAM system, and data is transmitted in the BPSK modulation system. At the same time, the demodulation side estimates the frequency offset amount and amplitude distortion amount between the transmitter and the receiver as pilot symbols, and performs quasi-synchronous detection. Here, the configurations of the 16QAM symbol and the BPSK modulation symbol in the N symbols are not limited to those in FIG. Although described the 16QAM scheme as an example, the same applies to the 2 ^2m-QAM scheme, multilevel QAM scheme or the 8 value this time is not limited to the 2 ^2m-QAM scheme. The BPSK modulation method has been described as an example of the PSK modulation method, but the PSK modulation method is not limited to this.

  As described above, according to the present embodiment, a PSK modulation scheme is periodically inserted into the multi-level QAM scheme of eight or more values, differential encoding is performed between PSK modulation symbols, and A modulation system in which an information sequence of signal points of a multilevel QAM system is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol, or a PSK modulation system is periodically inserted into the 16QAM system, and PSK modulation symbols Is a modulation system in which the 16QAM system signal point information sequence is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol. In the PSK modulation system, data is transmitted at the same time between the transmitter and the receiver. In order to estimate the frequency offset amount and amplitude distortion amount between the transmitter and receiver by using the pilot symbol for estimating the frequency offset amount and amplitude distortion amount of Known data in comparison with the method in which a pilot symbol, it is possible to perform quasi-synchronous detection without reducing the amount of data transmission.

  In the present embodiment, a differential encoding is performed between PSK modulation symbols, and the information sequence of the signal points of the multilevel QAM scheme of 8 values or more is arranged with reference to the signal point position of the immediately preceding PSK modulation symbol, Alternatively, the 16QAM signal point information series has been described with reference to the signal point position of the immediately preceding PSK modulation symbol. However, in any case, a PSK modulation symbol differentially encoded between PSK modulation symbols may be inserted. Similar effects can be obtained.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 4)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

  The signal point arrangement on the in-phase I-orthogonal Q plane of the 8-phase PSK modulation system, which is an example of a multi-level modulation system with 8 or more values, is the same as in FIG. 2 of the first embodiment. FIG. 14 shows the signal point arrangement of the QPSK modulation method in the in-phase I-orthogonal Q plane. In FIG. 14, reference numeral 1301 denotes the signal point of the QPSK modulation method. FIG. 15 shows an example of a configuration in N symbols of an 8-phase PSK modulation symbol and a QPSK modulation symbol. FIG. 16 shows an example of an information sequence arrangement of signal points of the QPSK modulation method when differential encoding is performed.

  FIGS. 17A, 17B, 17C, and 17D are examples of the relationship between the information sequence of the signal point of the immediately preceding QPSK modulation symbol and the signal point of the 8-phase PSK modulation system. Is a signal point of the QPSK modulation system, and 1602 is a signal point of the 8-phase PSK modulation system.

  1, 2, and 14 to 17, in a modulation scheme in which a QPSK modulation scheme is periodically inserted in an 8-level or more multi-level modulation scheme, differential encoding is performed between QPSK modulation symbols, A modulation system in which an information sequence of signal points of an 8-level or more multi-level modulation system is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol will be described.

  The signal point arrangement of the 8-phase PSK modulation method is as shown in FIG. 2 and is the same as in the first embodiment.

  FIG. 14 shows the arrangement of signal points 1301 of the QPSK modulation method in the in-phase I-quadrature Q plane, and the arrangement position of the signal points 1301 is expressed by (Equation 8). However, the signal point 1301 of the QPSK modulation system is represented by (IQPSK, QQPSK), k is an integer, and u is a constant.

  FIG. 15 shows an example of the configuration of 8-phase PSK modulation symbols and QPSK modulation symbols in N symbols. At this time, assuming that the phase of the i-th QPSK modulation symbol in the in-phase I-quadrature Q plane is φi and the phase of the i + N-th QPSK modulation symbol in the in-phase I-quadrature Q-plane is φi + N, the i + N-th in the xy plane If the phase θi + N of (1) is (Equation 3), the information sequence can be defined by θi + N as shown in FIG.

  FIG. 17 shows an example of the relationship between the information sequence of the signal point 1601 of the immediately preceding QPSK modulation symbol and the signal point 1602 of the 8-phase PSK modulation system. The information sequence of the signal point 1601 of the i-th QPSK modulation symbol and the signal point 1602 of the (i + 1) to (i + 1) to (i + N-1) -th 8-phase PSK modulation symbol is shown in FIG. 17 (a), (b), (c) or (d). Thus, the information sequence of the signal points of the 8-phase PSK modulation symbol is determined by the signal points of the immediately preceding QPSK modulation symbol.

  As described above, in the 8-phase PSK modulation system, data is transmitted, and in the QPSK modulation system, data is transmitted, and at the same time, the frequency offset amount and the amplitude distortion amount between the transceivers are estimated as pilot symbols on the demodulation side, and quasi-synchronous detection is performed. . Here, the configuration of the 8-phase PSK modulation symbol and the QPSK modulation symbol in the N symbols is not limited to FIG. Further, although an eight-phase PSK modulation method has been described as an example of a multi-level modulation method with eight or more values, a multi-value modulation method with eight or more values is not limited to this.

  As described above, according to the present embodiment, a QPSK modulation scheme is periodically inserted into a multi-level modulation scheme of eight or more values, differential encoding is performed between QPSK modulation symbols, and a multi-level of eight or more values is obtained. A modulation method in which an information sequence of modulation signal points is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. In the QPSK modulation method, the frequency offset amount and amplitude distortion between the transmitter and the receiver are transmitted simultaneously with data transmission. By using pilot symbols for estimating the amount of data, the amount of data transmission can be reduced without reducing the amount of data transmission compared to a method using known data as pilot symbols to estimate the amount of frequency offset and amplitude distortion between transmitters and receivers. Synchronous detection can be performed.

  In the present embodiment, a system is described in which differential encoding is performed between QPSK modulation symbols, and an information sequence of signal points of a multilevel modulation scheme of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. However, the same effect can be obtained by inserting a QPSK modulation symbol differentially encoded between QPSK modulation symbols.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 5)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

The signal point arrangement on the in-phase I-orthogonal Q plane of the 22 ^m- value QAM method, which is an example of a multi-value QAM method of 8 or more values, is the same as that of FIG. Further, the signal point arrangement in the in-phase I-quadrature Q plane of the QPSK modulation method is the same as that in FIG. 14 of the fourth embodiment. The signal point arrangement in the in-phase I-quadrature Q plane of the 16QAM system is the same as that in FIG. FIG. 18 shows an example of a configuration in N symbols of 16QAM symbols and QPSK modulation symbols. An example of the information sequence arrangement of signal points of the QPSK modulation method when differential encoding is performed is the same as that in FIG. 16 of the fourth embodiment.

  19 (a), (b), (c) and (d) are examples of the relationship between the signal sequence of the immediately preceding QPSK modulation symbol and the 16QAM signal point. In FIG. 19, reference numeral 1801 denotes the QPSK modulation scheme. The signal point 1802 is a 16QAM signal point.

  Referring to FIGS. 1, 7, 8, 14, 16, 18, and 19, in a modulation scheme in which a QPSK modulation scheme is periodically inserted into a multilevel QAM scheme of eight or more levels, It is differentially encoded between modulation symbols, and a modulation system in which an information sequence of signal points of a multilevel QAM system of 8 or more values is arranged on the basis of the signal point position of the immediately preceding QPSK modulation symbol, or periodically in the 16QAM system In the modulation scheme in which a QPSK modulation scheme is inserted, a modulation scheme is described in which differential encoding is performed between QPSK modulation symbols and an information sequence of 16QAM scheme signal points is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol.

The signal point arrangement of the 22 ^m- value QAM system is as shown in FIG. 7 and is the same as that described in the second embodiment. The signal point arrangement of the 16QAM system is as shown in FIG. 8, and is the same as that described in the second embodiment. The signal point arrangement of the QPSK modulation method is as shown in FIG. 14 and is the same as that described in the fourth embodiment.

  FIG. 18 shows an example of the configuration of 16QAM symbols and QPSK modulation symbols in N symbols. At this time, assuming that the phase of the i-th QPSK modulation symbol in the in-phase I-quadrature Q plane is φi and the phase of the i + N-th QPSK modulation symbol in the in-phase I-quadrature Q-plane is φi + N, the i + N-th in the xy plane If the phase θi + N of (1) is (Equation 3), the information sequence can be defined by θi + N as shown in FIG.

  FIG. 19 shows an example of the relationship between the information sequence of signal point 1801 of the immediately preceding QPSK modulation symbol and signal point 1802 of the 16QAM system. The information sequence of the signal point 1801 of the i-th QPSK modulation symbol and the signal point 1802 of the (i + 1) to (i + 1) to (i + N-1) -th 16QAM symbol is determined in four ways as shown in FIG. 19 (a), (b), (c) or (d). Thus, the information sequence of the signal points of 16QAM symbols is determined by the signal points of the immediately preceding QPSK modulation symbol.

As described above, data is transmitted in the 16QAM system, and data is transmitted in the QPSK modulation system. At the same time, the demodulation side estimates the frequency offset amount and the amplitude distortion amount between the transmitter and the receiver as pilot symbols, and performs quasi-synchronous detection. Here, the configuration of 16QAM symbols and QPSK modulation symbols in N symbols is not limited to that shown in FIG. Although the 16 QAM system has been described as an example, the same applies to the 2 ^2m- value QAM system. At this time, multi-value QAM of 8 values or more is not limited to the 2 ^2m- value QAM system.

  As described above, according to the present embodiment, a QPSK modulation scheme is periodically inserted into a multilevel QAM scheme of 8 or more values, differential encoding is performed between QPSK modulation symbols, and a multilevel of 8 or more values is obtained. In a modulation system in which an information sequence of QAM signal points is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol, or in a modulation system in which a QPSK modulation system is periodically inserted into the 16 QAM system, between QPSK modulation symbols Is a modulation method in which an information sequence of 16QAM signal points is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. In the QPSK modulation method, data is transmitted at the same time between the transmitter and the receiver. By using pilot symbols to estimate frequency offset and amplitude distortion, frequency offset and amplitude distortion between transceivers Can be compared to the method in which a pilot symbol of known data in order to estimate, performs quasi-synchronous detection without reducing the amount of data transmission.

  In the present embodiment, a method of differentially encoding between QPSK modulation symbols and arranging an information series of multi-level QAM signal points of 8 or more values with reference to the signal point position of the immediately preceding QPSK modulation symbol, or The 16QAM signal point information series has been described with reference to the signal point position of the immediately preceding QPSK modulation symbol. However, in any case, a QPSK modulation symbol differentially encoded between QPSK modulation symbols can be inserted. An effect is obtained.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 6)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

  The signal point arrangement in the in-phase I-orthogonal Q plane of the 8-phase PSK modulation system, which is an example of a multi-level modulation system with 8 or more values, is the same as in FIG. 2 of the first embodiment. FIG. 20 shows the signal point arrangement of the QPSK modulation method having signal points on the in-phase I axis and the orthogonal Q axis in the in-phase I-orthogonal Q plane. In FIG. 20, reference numeral 1901 denotes the signal point of the QPSK modulation method. FIG. 15 shows an example of a configuration in N symbols of an 8-phase PSK modulation symbol and the QPSK modulation symbol. An example of the information sequence arrangement of the signal points of the QPSK modulation method at the time of differential encoding is the same as FIG. 16 of the fourth embodiment. 21 (a), (b), (c) and (d) are examples of the relationship between the information sequence of the signal point of the immediately preceding QPSK modulation symbol and the signal point of the 8-phase PSK modulation system. 2001 is a signal point of the QPSK modulation system, and 2002 is a signal point of the 8-phase PSK modulation system.

  1, 2, 15, 16, 20, and 21, the QPSK modulation is performed in a modulation scheme in which the QPSK modulation scheme is periodically inserted into a multi-level modulation scheme having eight or more values. A modulation scheme in which symbols are differentially encoded and an information sequence of signal points of a multilevel modulation scheme of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol will be described.

  The signal point arrangement of the 8-phase PSK modulation method is as shown in FIG. 2 and is the same as that described in the first embodiment.

  FIG. 20 shows an arrangement of the signal points 1901 of the QPSK modulation method in the in-phase I-quadrature Q plane, and the arrangement of the signal points 1901 is expressed by (Equation 9). However, the signal point 1901 of the QPSK modulation method is represented by (IQPSKR, QQPSKR), (IQPSK, QQPSK) is represented by (Expression 2), and n is an integer.

  FIG. 15 shows an example of the configuration of an 8-phase PSK modulation symbol and the QPSK modulation symbol in N symbols. At this time, if the phase of the i-th QPSK modulation symbol in the in-phase I-quadrature Q plane is φi, and the phase of the i + N-th QPSK modulation symbol in the in-phase I-quadrature Q-plane is φi + N, then in the xy plane Assuming that the i + N-th phase θi + N is (Expression 3), the information sequence can be determined by θi + N as shown in FIG.

  FIG. 21 shows an example of the relationship between the information sequence of the signal point 2001 of the immediately preceding QPSK modulation symbol and the signal point 2002 of the 8-phase PSK modulation system. The information sequence of the signal point 2001 of the i-th QPSK modulation symbol and the signal point 2002 of the (i + 1) to (i + 1) to (i + N-1) -th 8-phase PSK modulation symbol is shown in FIG. 21 (a), (b), (c) or (d). As described above, the information sequence of the signal points of the 8-phase PSK modulation symbol is determined by the signal points of the immediately preceding QPSK modulation symbol.

  In this way, data is transmitted in the 8-phase PSK modulation method, and data is transmitted in the QPSK modulation method. At the same time, the demodulation side estimates the frequency offset amount and the amplitude distortion amount between the transceivers as pilot symbols, and performs quasi-synchronous detection. Do. Here, the configuration of the 8-phase PSK modulation symbol in the N symbols and the QPSK modulation symbol is not limited to that shown in FIG. Further, although an eight-phase PSK modulation method has been described as an example of a multi-level modulation method with eight or more values, a multi-value modulation method with eight or more values is not limited to this.

  As described above, according to the present embodiment, the QPSK modulation scheme is periodically inserted into the multi-level modulation scheme of eight or more values, differential encoding is performed between the QPSK modulation symbols, and eight or more values are coded. A modulation scheme in which an information sequence of signal points of a multi-level modulation scheme is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. In the QPSK modulation scheme, a frequency offset between a transmitter and a transmitter is simultaneously transmitted on the demodulation side. By using pilot symbols to estimate the amount and amplitude distortion, the amount of data transmission is reduced compared to the method using known data as pilot symbols to estimate the frequency offset and amplitude distortion between the transceivers Quasi-synchronous detection can be performed without doing so.

  In the present embodiment, a differential encoding is performed between the QPSK modulation symbols, and an information sequence of signal points of a multilevel modulation scheme of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. However, the same effect can be obtained by inserting QPSK modulation symbols differentially encoded between the QPSK modulation symbols.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 7)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

The signal point arrangement on the in-phase I-orthogonal Q plane of the 22 ^m- value QAM method, which is an example of a multi-value QAM method of 8 or more values, is the same as that of FIG. The signal point arrangement of the QPSK modulation method having signal points on the in-phase I axis and the orthogonal Q axis in the in-phase I-orthogonal Q plane is the same as that in FIG. 20 of the sixth embodiment. The signal point arrangement in the in-phase I-quadrature Q plane of the 16QAM system is the same as that in FIG. FIG. 18 shows an example of a configuration in N symbols of 16QAM symbols and the QPSK modulation symbols. An example of the information sequence arrangement of the signal points of the QPSK modulation method at the time of differential encoding is the same as FIG. 16 of the fourth embodiment. 22 (a), (b), (c), and (d) are examples of the relationship between the information sequence of the signal point of the immediately preceding QPSK modulation symbol and the signal point of 16QAM. In FIG. 22, 2101 indicates the QPSK. Modulation signal points 2102 are 16QAM signal points.

  In the modulation scheme in which the QPSK modulation scheme is periodically inserted into the multi-level QAM scheme of 8 or more values using FIG. 1, FIG. 7, FIG. 8, FIG. 16, FIG. 18, FIG. Among the QPSK modulation symbols, differential encoding is performed, and an information sequence of multi-level QAM system signal points of 8 or more values is arranged based on the signal point position of the immediately preceding QPSK modulation symbol, or 16QAM system In the modulation scheme in which the QPSK modulation scheme is periodically inserted, differential encoding is performed between the QPSK modulation symbols, and an information sequence of 16QAM scheme signal points is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol The modulation method will be described.

The signal point arrangement of the 22 ^m- value QAM system is as shown in FIG. 7 and is the same as that described in the second embodiment. The signal point arrangement of the 16QAM system is as shown in FIG. 8, and is the same as that described in the second embodiment. The signal point arrangement of the QPSK modulation method is as shown in FIG. 20, and is the same as that described in the sixth embodiment.

  FIG. 18 shows an example of the configuration of 16QAM symbols and QPSK modulation symbols in N symbols. At this time, if the phase of the i-th QPSK modulation symbol in the in-phase I-quadrature Q plane is φi, and the phase of the i + N-th QPSK modulation symbol in the in-phase I-quadrature Q-plane is φi + N, then in the xy plane When the i + N-th phase is θi + N (Equation 3), the information sequence can be determined by θi + N as shown in FIG.

  FIG. 22 shows an example of the relationship between the information sequence of the signal point 2101 of the immediately preceding QPSK modulation symbol and the signal point 2102 of the 16QAM system. The information sequence of the signal point 2101 of the i-th QPSK modulation symbol and the signal point 2102 of the (i + 1) to (i + 1) to (i + N-1) -th 16QAM symbols is as shown in FIG. 22 (a), (b), (c) or (d). The information sequence of 16QAM symbol signal points is determined by the signal point of the immediately preceding QPSK modulation symbol.

In this way, data is transmitted in the 16QAM system, and data is transmitted in the QPSK modulation system. At the same time, the demodulation side estimates the frequency offset amount and amplitude distortion amount between the transmitter and the receiver as pilot symbols, and performs quasi-synchronous detection. Here, the configuration of the 16QAM symbols in the N symbols and the QPSK modulation symbols is not limited to that shown in FIG. Although the 16 QAM system has been described as an example, the same applies to the 2 ^2m- value QAM system. At this time, multi-value QAM of 8 values or more is not limited to the 2 ^2m- value QAM system.

  As described above, according to the present embodiment, the QPSK modulation scheme is periodically inserted into the multi-level QAM scheme of eight or more values, differential encoding is performed between the QPSK modulation symbols, and eight or more values are used. The QPSK modulation scheme is periodically inserted into a modulation scheme in which an information sequence of signal points of a multilevel QAM scheme is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol, or the 16QAM scheme, and the QPSK modulation This is a modulation method in which a differential encoding is performed between symbols and an information sequence of 16QAM signal points is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. In the QPSK modulation method, data is transmitted and simultaneously demodulated. By using pilot symbols for estimating the frequency offset and amplitude distortion between the transceivers, the frequency offset between the transceivers and Compared to method of the pilot symbol known data to estimate the amplitude distortion amount, it is possible to perform quasi-synchronous detection without reducing the amount of data transmission.

  In the present embodiment, a differential encoding is performed between the QPSK modulation symbols, and an information sequence of multi-level QAM system signal points of eight or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. Alternatively, the description has been given of the method in which the information sequence of 16QAM signal points is arranged based on the signal point position of the immediately preceding QPSK modulation symbol. In either case, a QPSK modulation symbol differentially encoded between the QPSK modulation symbols is inserted. The same effect can be obtained.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 8)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

In the in-phase I-orthogonal Q plane, a 22 ^m- value QAM system is used in the in-phase I-orthogonal Q plane, which is an example of the 8-level or more multi-level QAM system obtained by rotating a signal point of the 8-level or more multi-level QAM system by π / 4 radians. The signal point arrangement in the in-phase I-orthogonal Q plane of the 22 ^m- value QAM system obtained by rotating the signal point of π / 4 radians is the same as in FIG. 11 of the third embodiment. The signal point arrangement of the QPSK modulation method in the in-phase I-orthogonal Q plane is the same as in FIG. 14 of the fourth embodiment. The signal point arrangement on the in-phase I-orthogonal Q plane of the 16QAM system obtained by rotating the 16QAM system signal points by π / 4 radians on the in-phase I-orthogonal Q plane is the same as that of FIG. FIG. 18 shows an example of a configuration in N symbols of the 16QAM symbol and the QPSK modulation symbol. An example of the information sequence arrangement of signal points of the QPSK modulation method when differential encoding is performed is the same as that in FIG. 16 of the fourth embodiment. 23 (a), (b), (c), and (d) are examples of the relationship between the signal sequence of the immediately preceding QPSK modulation symbol and the information sequence of the 16QAM signal point. In FIG. 23, 2201 indicates QPSK modulation. Signal points of the system 2202 are signal points of the 16QAM system.

  In the modulation scheme in which a QPSK modulation scheme is periodically inserted into the multilevel QAM scheme of 8 or more values using FIG. 1, FIG. 11, FIG. 12, FIG. 14, FIG. QPSK modulation symbols are differentially encoded, and the modulation system in which the information sequence of the signal points of the multi-level QAM scheme of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol, or the 16QAM scheme In a modulation system that periodically inserts a QPSK modulation system, a modulation system that differentially encodes between QPSK modulation symbols and places an information sequence of signal points of the 16QAM system on the basis of the signal point position of the immediately preceding QPSK modulation symbol Will be described.

The signal point arrangement of the 22 ^m- value QAM system is as shown in FIG. 11 and is the same as that described in the third embodiment. The signal point arrangement of the 16QAM system is as shown in FIG. 12, and is the same as that described in the third embodiment. The signal point arrangement of the QPSK modulation method is as shown in FIG. 14 and is the same as that described in the fourth embodiment.

  FIG. 18 shows an example of the configuration of the 16QAM symbol and the QPSK modulation symbol in N symbols. At this time, assuming that the phase of the i-th QPSK modulation symbol in the in-phase I-quadrature Q plane is φi and the phase of the i + N-th QPSK modulation symbol in the in-phase I-quadrature Q-plane is φi + N, the i + N-th in the xy plane If the phase θi + N of (1) is (Equation 3), the information sequence can be defined by θi + N as shown in FIG.

  FIG. 23 shows an example of the relationship between the information sequence of the signal point 2201 of the immediately preceding QPSK modulation symbol and the signal point 2202 of the 16QAM system. The information series of the signal point 2201 of the i-th QPSK modulation symbol and the signal point 2202 of the 16QAM symbol of the (i + 1) to (i + 1) to (i + N) -th are as shown in FIG. 23 (a), (b), (c) or (d). The information sequence of the signal point of the 16QAM symbol is determined by the signal point of the immediately preceding QPSK modulation symbol.

In this way, data is transmitted in the 16QAM system, and data is transmitted in the QPSK modulation system. At the same time, the demodulation side estimates the frequency offset amount and the amplitude distortion amount between the transceivers as pilot symbols, and performs quasi-synchronous detection. Here, the configuration of the 16QAM symbols and QPSK modulation symbols in the N symbols is not limited to that shown in FIG. Furthermore, the 16QAM scheme also applies to the but the 2 ^2m-QAM scheme described as an example, the multi-level QAM over the 8 value this time is not limited to the 2 ^2m-QAM scheme.

  As described above, according to the present embodiment, a QPSK modulation scheme is periodically inserted into the multilevel QAM scheme of eight or more values, differential encoding is performed between QPSK modulation symbols, and A modulation system in which an information sequence of signal points of the multi-level QAM system is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol, or a QPSK modulation system is periodically inserted into the 16QAM system, and between QPSK modulation symbols Is a modulation system in which the 16QAM system signal point information sequence is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. In the QPSK modulation system, data is transmitted and the transmitter and the By using pilot symbols to estimate the frequency offset amount and amplitude distortion amount, the frequency offset amount and amplitude distortion amount between the transmitter and the receiver Compared to method of the pilot symbol known data to estimate, it is possible to perform quasi-synchronous detection without reducing the amount of data transmission.

  In the present embodiment, a differential encoding is performed between QPSK modulation symbols, and an information sequence of signal points of the multi-level QAM scheme of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol, Alternatively, the 16QAM signal point information series has been described with reference to the signal point position of the immediately preceding QPSK modulation symbol. However, in any case, if a QPSK modulation symbol differentially encoded between QPSK modulation symbols is inserted, Similar effects can be obtained.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

(Embodiment 9)
The configuration of the wireless communication system in the present embodiment is the same as that shown in FIG.

In the in-phase I-orthogonal Q plane, a 22 ^m- value QAM system is used in the in-phase I-orthogonal Q plane, which is an example of the 8-level or more multi-level QAM system obtained by rotating a signal point of the 8-level or more multi-level QAM system by π / 4 radians. The signal point arrangement in the in-phase I-orthogonal Q plane of the 22 ^m- value QAM system obtained by rotating the signal point of π / 4 radians is the same as in FIG. 11 of the third embodiment. The signal point arrangement of the QPSK modulation method having signal points on the in-phase I axis and the orthogonal Q axis in the in-phase I-orthogonal Q plane is the same as that in FIG. 20 of the sixth embodiment. The signal point arrangement on the in-phase I-orthogonal Q plane of the 16QAM system obtained by rotating the 16QAM system signal points by π / 4 radians on the in-phase I-orthogonal Q plane is the same as that of FIG. FIG. 18 shows an example of a configuration in N symbols of the 16QAM symbol and the QPSK modulation symbol. An example of the information sequence arrangement of the signal points of the QPSK modulation method at the time of differential encoding is the same as FIG. 16 of the fourth embodiment. 24 (a), (b), (c) and (d) are examples of the relationship between the information sequence of the signal point of the immediately preceding QPSK modulation symbol and the signal point of 16QAM. In FIG. QPSK modulation signal points 2302 are the 16QAM signal points.

  In FIG. 1, FIG. 11, FIG. 12, FIG. 16, FIG. 18, FIG. 20, FIG. 24, in the modulation scheme in which the QPSK modulation scheme is periodically inserted into the multi-level QAM scheme of 8 or more values. A modulation scheme in which differential encoding is performed between the QPSK modulation symbols, and an information sequence of signal points of the multilevel QAM scheme of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol, or the 16QAM scheme In the modulation scheme in which the QPSK modulation scheme is periodically inserted, differential coding is performed between the QPSK modulation symbols, and the signal point position of the immediately preceding QPSK modulation symbol is converted from the information sequence of the 16QAM signal points. A modulation scheme arranged as a reference will be described.

The signal point arrangement of the 22 ^m- value QAM system is as shown in FIG. 11 and is the same as that described in the third embodiment. The signal point arrangement of the 16QAM system is as shown in FIG. 12, and is the same as that described in the third embodiment. The signal point arrangement of the QPSK modulation method is as shown in FIG. 20, and is the same as that described in the sixth embodiment.

  FIG. 18 shows an example of the configuration of the 16QAM symbol and the QPSK modulation symbol in N symbols. At this time, if the phase of the i-th QPSK modulation symbol in the in-phase I-quadrature Q plane is φi, and the phase of the i + N-th QPSK modulation symbol in the in-phase I-quadrature Q-plane is φi + N, then in the xy plane Assuming that the i + N-th phase θi + N is (Expression 3), the information sequence can be determined by θi + N as shown in FIG.

  FIG. 24 shows an example of the relationship between the information sequence of the signal point 2301 of the immediately preceding QPSK modulation symbol and the signal point 2302 of the 16QAM system. The information sequence of the signal point 2301 of the i-th QPSK modulation symbol and the signal point 2302 of the 16th QAM symbol of the (i + 1 to i + N-1) th is as shown in FIG. 24 (a), (b), (c) or (d). In addition, the information sequence of the signal points of the 16QAM symbol is determined by the signal points of the immediately preceding QPSK modulation symbol.

In this way, data is transmitted in the 16QAM system, and data is transmitted in the QPSK modulation system. At the same time, the demodulation side estimates the frequency offset amount and the amplitude distortion amount between the transceivers as pilot symbols, and performs quasi-synchronous detection. Here, the configurations of the 16QAM symbols and the QPSK modulation symbols in the N symbols are not limited to those in FIG. Furthermore, the 16QAM scheme also applies to the but the 2 ^2m-QAM scheme described as an example, the multi-level QAM over the 8 value this time is not limited to the 2 ^2m-QAM scheme.

  As described above, according to the present embodiment, the QPSK modulation scheme is periodically inserted into the multilevel QAM scheme of 8 or more values, differential encoding is performed between the QPSK modulation symbols, and the 8-level The QPSK modulation scheme is periodically inserted into the modulation scheme in which the information sequence of the signal points of the multi-level QAM scheme is arranged based on the signal point position of the immediately preceding QPSK modulation symbol, or the 16QAM scheme, The QPSK modulation symbol is differentially encoded, and the 16QAM system signal point information sequence is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. In the QPSK modulation system, data is transmitted. At the same time, the frequency between transmitters and receivers is determined by using pilot symbols to estimate the frequency offset and amplitude distortion between transmitters and receivers on the demodulation side. Compared to method of the pilot symbol known data to estimate the offset amount and the amplitude distortion amount, it is possible to perform quasi-synchronous detection without reducing the amount of data transmission.

  In the present embodiment, differential encoding is performed between the QPSK modulation symbols, and an information sequence of multi-level QAM signal points of 8 or more values is arranged with reference to the signal point position of the immediately preceding QPSK modulation symbol. The system, or the system in which the information sequence of the signal points of the 16QAM system is arranged on the basis of the signal point position of the immediately preceding QPSK modulation symbol, has been explained, but both are QPSK modulation symbols differentially encoded between the QPSK modulation symbols The same effect can be obtained by inserting.

  Further, by using such a modulation method, it is possible to construct a communication system that suppresses a decrease in the amount of data transmission.

  Next, an example in which a simulation is specifically performed for the present invention will be described.

  In this embodiment, a 16QAM scheme is selected as an example of the multi-level QAM scheme, and the pilot symbol insertion method is compared with the conventional symbol insertion scheme and the QPSK modulation symbol insertion scheme according to the present invention. . At this time, the known or QPSK modulation symbol length is set to 1, and the data symbol length is set to n.

  The conventional symbol insertion method is a method in which one signal point of the maximum signal point amplitude of 16QAM is a pilot symbol, and 16QAM is quasi-synchronously detected on the receiving side.

  The QPSK modulation symbol insertion method according to the present invention is a method in which QPSK modulation symbols are used as pilot symbols and data transmission is performed simultaneously, and 16QAM mapping depends on the immediately preceding QPSK modulation symbol. Further, QPSK modulation symbols are differentially encoded. On the receiving side, 16QAM is detected quasi-synchronously and QPSK is delayed.

  FIG. 25 shows a bit error ratio (BER) characteristic diagram in the noise power density (N0) with respect to the signal energy (Eb) per bit of the modulation system according to the present embodiment. In the above method, n = 1. , 7, and 15 show the respective characteristics. FIG. 25 shows that when the data symbol lengths of the known conventional symbol insertion scheme and the QPSK modulation symbol insertion scheme of the present invention are equal, the QPSK modulation symbol insertion scheme performs data transmission by performing data transmission with QPSK modulation symbols. It can be seen that the transmission efficiency is excellent and the BER characteristics are excellent.

The figure which shows the structure of the radio | wireless communications system by one embodiment of this invention. Signal point arrangement diagram of 8-phase PSK modulation system according to one embodiment of the present invention BPSK modulation scheme signal point arrangement diagram according to an embodiment of the present invention The figure which shows the frame structure of the signal by one embodiment of this invention The figure which shows an example of the relationship between the signal point of an BPSK modulation system in xy plane at the time of differential encoding by one embodiment of this invention, and an information sequence The figure which shows an example of the relationship between the signal point of an BPSK modulation system, the signal point of an 8-phase PSK modulation system, and an information series by one embodiment of this invention Signal point arrangement diagram of 22 ^m- value QAM system according to one embodiment of the present invention 16QAM signal point arrangement diagram according to an embodiment of the present invention The figure which shows the frame structure of the signal by one embodiment of this invention The figure which shows an example of the relationship between the signal point of a BPSK modulation system, the signal point of 16QAM system, and an information sequence by one embodiment of this invention Signal point arrangement diagram of 22 ^m- value QAM system according to one embodiment of the present invention 16QAM signal point arrangement diagram according to an embodiment of the present invention The figure which shows an example of the relationship between the signal point of a BPSK modulation system, the signal point of 16QAM system, and an information sequence by one embodiment of this invention Signal point arrangement diagram of QPSK modulation system according to one embodiment of the present invention The figure which shows an example of a structure of the 8-phase PSK modulation symbol and QPSK modulation symbol in N symbols by one embodiment of this invention The figure which shows an example of the relationship between the signal point of a QPSK modulation system in xy plane at the time of differential encoding by one embodiment of this invention, and an information sequence The figure which shows an example of the relationship of the signal point of QPSK modulation system, the signal point of 8-phase PSK modulation system, and an information sequence by one embodiment of this invention The figure which shows an example of a structure of 16QAM symbol and QPSK modulation symbol in N symbol by one embodiment of this invention The figure which shows an example of the relationship between the signal point of QPSK modulation system, the signal point of 16QAM system, and an information sequence by one embodiment of this invention Signal point arrangement diagram of QPSK modulation system according to one embodiment of the present invention The figure which shows an example of the relationship of the signal point of QPSK modulation system, the signal point of 8-phase PSK modulation system, and an information sequence by one embodiment of this invention The figure which shows an example of the relationship between the signal point of QPSK modulation system, the signal point of 16QAM system, and an information sequence by one embodiment of this invention The figure which shows an example of the relationship between the signal point of QPSK modulation system, the signal point of 16QAM system, and an information sequence by one embodiment of this invention The figure which shows an example of the relationship between the signal point of QPSK modulation system, the signal point of 16QAM system, and an information sequence by one embodiment of this invention The figure which shows the bit error rate characteristic in the noise power density with respect to the signal energy per bit of the modulation system by one Example of this invention. The figure which shows the frame structure of the signal transmitted conventionally.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Transmission digital signal 12 Quadrature baseband modulation part 13 Transmission quadrature baseband signal in-phase component 14 Transmission quadrature baseband signal quadrature component 15 Transmission radio part 16 Transmission signal 17, 21 Antenna 22 Reception radio part 23 Reception quadrature base hand signal in-phase component 24 Received quadrature baseband signal quadrature component 25 Amplitude distortion amount estimation unit 26 Frequency offset amount estimation unit 27 Amplitude distortion amount estimation signal 28 Frequency offset amount estimation signal 29 Quasi-synchronous detection unit 30 Received digital signal 101, 502, 1602, 1801, 2002 8 Phase PSK modulation system signal points 201, 501, 901, 1201 BPSK modulation system signal points 601 2 ^2m- value QAM system signal points 701, 902, 1802, 2102 16QAM system signal points 1001 2 in the in-phase I-orthogonal Q plane ^2m Signal points of a QAM scheme [pi / 4 radians the rotated 2 ^2m-QAM scheme signal point 1101,1202,2202,2302 phase I- quadrature Q 16QAM scheme signal points of 16QAM scheme was [pi / 4 radians rotation in the plane of Signal points of 1301, 1601, 2201 QPSK modulation method Signal points 1901, 2001, 2101, 2301 Signal points of QPSK modulation method having signal points on the in-phase I axis and the orthogonal Q axis in the in-phase I-orthogonal Q plane

Claims (9)

  A phase shift keying (PSK) method, which is a second modulation method, is regularly inserted into a multi-level modulation method, which is a first modulation method, for use in wireless communication and transmission, In the case of reception, at least the amplitude distortion amount between the transmitter and the transmitter among the frequency offset amount of the received signal and the amplitude distortion amount between the transmitter and the receiver is received. Modulation method determined from symbols.   Used in wireless communication, in the case of transmission, a phase modulation (PSK: Phase Shift Keying) method that is a second modulation method is regularly inserted as a pilot signal into a multi-level modulation method that is a first modulation method. In the case of reception, differential encoding is performed between the symbols of the second modulation scheme, and at the time of reception, at least the amplitude distortion amount between the transmitter and the transmitter among the frequency offset amount of the received signal and the amplitude distortion amount between the transmitter and the receiver is calculated from the pilot signal. The desired modulation method.   Used in wireless communication, in the case of transmission, data is added to a symbol of a multi-level modulation scheme that is the first modulation scheme, and the second modulation scheme is regularly between the symbols of the first modulation scheme. Phase shift keying (PSK) system symbols are inserted, differential encoding is performed between symbols of the second modulation system, and in the case of reception, the received signal is converted using the symbols of the second modulation system. A modulation scheme that demodulates the symbols of the first modulation scheme by estimating and removing at least the amplitude distortion amount between the transmitter and the transmitter out of the frequency offset amount and the amplitude distortion amount between the transmitter and the receiver.   Used in wireless communication, in the case of transmission, data is added to a symbol of a multi-level modulation scheme that is the first modulation scheme, and the second modulation scheme is regularly between the symbols of the first modulation scheme. A phase shift keying (PSK) system symbol is inserted as a pilot signal, differentially encoded between the symbols of the second modulation system, and in the case of reception, a frequency offset of the received signal using the pilot signal A modulation scheme that demodulates symbols of the first modulation scheme by estimating and removing at least the amplitude distortion amount between the transmitter and the transmitter, and the amplitude distortion amount between the transmitter and the receiver.   5. The symbol according to claim 1, wherein data is added to the symbol of the second modulation scheme in the case of transmission, and the symbol of the second modulation scheme is demodulated by performing delay detection in the case of reception. The modulation method described in the above. In the transmitter of the communication partner, a phase modulation (PSK) system that is the second modulation system is regularly inserted into the multi-level modulation system that is the first modulation system, and the second modulation system A signal differentially encoded between the symbols is received from the transmitter,
A receiver receiving method for estimating at least an amplitude distortion amount between a transmitter and a receiver among a frequency offset amount of the received signal and an amplitude distortion amount between the transmitter and a receiver using the second symbol extracted from the received signal. In the transmitter of the communication partner, a phase modulation (PSK) system that is the second modulation system is regularly inserted as a pilot signal into the multi-level modulation system that is the first modulation system, and the second A signal differentially encoded between symbols of the modulation scheme is received from the transmitter,
A receiver receiving method for estimating at least an amplitude distortion amount between a transmitter and a receiver among a frequency offset amount of the received signal and an amplitude distortion amount between the transmitter and a receiver using the pilot signal extracted from the received signal. At the transmitter of the communication partner, data is added to the symbols of the multi-level modulation scheme that is the first modulation scheme, and phase modulation (PSK) that is the second modulation scheme regularly between the symbols of the first modulation scheme. : Phase Shift Keying) system symbol is inserted, and a signal differentially encoded between the symbols of the second modulation system is received from the transmitter,
Using the second symbol extracted from the received signal, estimate at least the amplitude distortion amount between the transmitter and the transmitter among the frequency offset amount of the received signal and the amplitude distortion amount between the transmitter and the receiver,
From the received signal of the first symbol, at least the amount of amplitude distortion between transmitters / receivers is removed from the estimated amount of frequency offset and the amount of amplitude distortion between transmitters / receivers, and the data added to the first symbol is demodulated. Receiver receiving method. At the transmitter of the communication partner, data is added to the symbols of the multi-level modulation scheme that is the first modulation scheme, and phase modulation (PSK) that is the second modulation scheme regularly between the symbols of the first modulation scheme. : Phase Shift Keying) symbol is inserted as a pilot signal, and a signal differentially encoded between the symbols of the second modulation scheme is received from the transmitter,
Estimating at least the amplitude distortion amount between the transceivers among the amplitude distortion amount and the frequency offset amount between the transceivers and the amplitude distortion amount between the transceivers using the pilot signal extracted from the received signal,
From the received signal of the first symbol, at least the amount of amplitude distortion between transmitters / receivers is removed from the estimated amount of frequency offset and the amount of amplitude distortion between transmitters / receivers, and the data added to the first symbol is demodulated. Receiver receiving method.

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