JP2007036491A - Transmitter, receiver and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the throughput of a multicarrier communication system using wavelet transform.
When a retransmission control information demodulating unit receives a communication error (NACK) from a receiver, a transmitter uses a subband mapping pattern determining unit to transmit a subband mapping pattern used by an inverse wavelet transform unit. Update. Along with this update, the transmitter 100 retransmits transmission data by performing wavelet transform with a different subband mapping pattern for each communication error detection. A receiver that receives the retransmitted data can use the interleaving effect between the received data.
[Selection] Figure 1

Description

  The present invention relates to a transmitter, a receiver, and a control method thereof according to a multicarrier communication scheme using orthogonal wavelet transform.

  In the conventional multicarrier communication system, an OFDM (Orthogonal Frequency Division Multiplexing) system has been put to practical use as a high-speed transmission technique that can reduce the influence of frequency selective fading caused by a multipath propagation path. Among other multi-carrier communication systems, there is WPM (Wavelet Packet Modulation) using wavelet transform for orthogonal transform (see Patent Document 1).

The communication system described in Patent Document 1 uses a discrete wavelet transform using orthogonal wavelet transform as a one-to-one reversible transform, and assigns one signal point to a component subjected to subband decomposition to generate a synthesized wave. This is used as a baseband modulation signal. Specifically, in the above-described prior art, highly reliable communication is performed as a whole system by assigning one signal point to orthogonal subbands of wavelet transform and performing transmission with different BER characteristics for each subband. be able to.
JP-A-11-275165

  However, in the above prior art, one signal point is allocated to subbands orthogonal to the wavelet transform, and transmission with different BER characteristics is performed for each subband. Since the same subband pattern is used, the throughput of the entire communication system is not improved.

  The present invention has been made in view of this point, and an object thereof is to improve the throughput of the entire communication system in a multicarrier communication system using wavelet transform.

  In order to solve such a problem, the transmitter of the present invention is a retransmission request detection means for detecting a retransmission request from a communication partner in a transmitter that performs orthogonal wavelet transform on transmission data to be multiplexed and transmits the data in a multicarrier communication system. When the retransmission request is detected, wavelet pattern determination means for updating and determining a wavelet pattern to which a plurality of signal points are assigned, and using the updated wavelet pattern, the transmission data is subjected to orthogonal inverse wavelet transform. And a wavelet modulation means for obtaining a multicarrier signal.

  Further, the receiver of the present invention is a receiver for receiving a signal transmitted by orthogonal inverse wavelet transform, wavelet pattern information demodulating means for demodulating wavelet pattern information from the received signal, and the demodulated wavelet pattern A receiving wavelet pattern determining unit that determines a wavelet pattern based on information, and a demodulating unit that demodulates a signal by performing orthogonal wavelet transform according to the determined wavelet pattern are employed.

  Also, the transmitter control method of the present invention is a retransmission request for detecting a retransmission request from a communication partner in a transmitter control method for performing orthogonal wavelet transform on multiplexed transmission data and multiplexing transmission using a multicarrier communication method. A detection step; a wavelet pattern determination step that updates and determines a wavelet pattern to which a plurality of signal points are assigned when the retransmission request is detected; and an orthogonal wavelet transform is performed on the transmission data using the updated wavelet pattern. And a wavelet modulation step for obtaining a multicarrier high-frequency signal.

  The receiver control method of the present invention is a receiver control method for receiving a signal transmitted by orthogonal inverse wavelet transform, and a wavelet pattern information demodulation step for demodulating wavelet pattern information from the received signal; A received wavelet pattern determining step for determining a wavelet pattern based on the demodulated wavelet pattern information, and a demodulating step for demodulating the signal by performing orthogonal wavelet transform according to the determined wavelet pattern are adopted.

  According to the present invention, by updating the wavelet pattern in retransmission control, the error probability for each information symbol is changed, an interleaving effect is obtained, and the throughput of the entire communication system is improved.

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

(Embodiment 1)
FIG. 1 is a block diagram of a transmitter according to Embodiment 1 of the present invention. Transmitter 100 according to the present embodiment includes S / P conversion section 101, inverse wavelet conversion section 102, D / A conversion section 103, transmission section 104, transmission antenna 105, reception antenna 106, and reception. Unit 107, retransmission control information demodulating unit 108, and subband mapping pattern determining unit 109. Note that the transmitting antenna 105 and the receiving antenna 106 may be shared and configured integrally.

  In FIG. 1, the S / P conversion unit 101 uses a predetermined subband mapping pattern at the time of initial transmission and transmits transmission data based on the subband pattern output from the subband mapping pattern determination unit 109 at the time of retransmission. P-converted and output to the inverse wavelet transform unit 102. The S / P conversion unit 101 also outputs the subband mapping pattern information to the inverse wavelet conversion unit 102 together with the transmission data series. The inverse wavelet transform unit 102 performs inverse wavelet transform on the input and outputs the result to the D / A conversion unit 103. The D / A conversion unit 103 converts the input signal into an analog signal and outputs the analog signal to the transmission unit 104. The transmission unit 104 converts the input signal into a high-frequency signal and outputs it to the transmission antenna 105. The transmission antenna 105 wirelessly transmits transmission data and subband mapping pattern information to the receiver of the communication partner.

  The receiving antenna 106 receives a radio signal from a receiver (not shown) and outputs it to the receiving unit 107. Receiving section 107 down-converts the received radio signal and outputs it to retransmission control information demodulating section 108. Retransmission control information demodulation section 108 demodulates the input signal, detects the presence or absence of a retransmission request from the receiver, and outputs a retransmission request signal to subband mapping pattern determination section 109 when there is a retransmission request. The subband mapping pattern determination unit 109 outputs a new subband mapping pattern to the S / P conversion unit 101.

  With such a configuration, transmitter 100 according to the present embodiment updates the subband mapping pattern for each retransmission due to a communication error, performs communication by wavelet transform using the new subband mapping pattern, and responds to the communication error. The interleaving effect is easily obtained.

  FIG. 2 is a schematic diagram showing wavelet patterns used in the transmitter and the receiver according to each embodiment of the present invention. As shown in FIG. 2, the wavelet pattern is expanded in two axial directions of the frequency axis (f) and the time axis (t) and decomposed into eight sections (each component obtained by subband decomposition). In the form, it is not necessary to use all, but a maximum of 8 signal points can be assigned. Moreover, it is not necessarily limited to eight sections.

  The orthogonal wavelet transform will be described in detail with reference to FIG. 2. In the orthogonal wavelet transform, the time resolution changes depending on the level of the subband, and the time resolution becomes lower as the frequency becomes lower. Therefore, the number of assigned signal points increases according to the higher level. Specifically, when the subband level 1 is Nw / 2 (Nw: information frame length), and the subband level is increased by one, the number of signal points is halved. At N-1, two signal points are assigned. However, two subband levels N are provided and assigned signal points respectively. The above is a typical signal point assignment in the wavelet transform. Therefore, FIG. 2 shows a typical time-frequency mapping example in the case of 8 signal points. Hereinafter, the subband level is abbreviated as SL as necessary.

  Now, the transmission characteristics when this typical time-frequency mapping is performed will be described. When the same signal point arrangement is applied to all subbands, the energy per information symbol is reduced in the lower level subbands. In the example of FIG. 2, the energy per information symbol has a relationship of {d1, d2, d3, d4} <{d5, d6} <{d7, d8}. In general, the higher the energy per information symbol, the better the transmission characteristic, and the lower the level, the better the signal quality. That is, communication using orthogonal wavelet transform can realize a multi-carrier communication system that can obtain a hierarchical BER characteristic, and can perform modulation with flexible setting of transmission efficiency and a BER characteristic that is in a trade-off relationship with the transmission efficiency. .

  In addition, the point which can implement | achieve this flexible multicarrier communication system is also the reason for which WPM attracts attention recently.

  As described above, the present invention realizes multicarrier communication using orthogonal wavelet transform, and there are two basic methods for constructing a wavelet pattern. One is a method of determining a subband pattern by determining a frequency axis and a time axis according to conditions in FIG. The other is a method in which the subband pattern is fixed like the typical subband pattern shown in FIG. 2, for example, and the assignment of signal points to each section is determined according to the conditions. This latter is referred to herein as a subband mapping pattern. Of course, the wavelet pattern is not fixed only to the above two methods, but can be configured in a combination of both as required. Here, Embodiment 1 according to the present invention will be described as using subband mapping pattern updating.

  FIG. 3 is a schematic diagram showing how the subband mapping pattern is updated. As shown in FIG. 3, the subband mapping pattern is developed in two axial directions, ie, the frequency axis (f) direction on the vertical axis and the time axis (t) direction on the horizontal axis, and is divided into several sections. Transmission data is assigned to each partition. In FIG. 3, there are eight sections, and transmission data (signal points) d1 to d8 can be assigned to each section. That is, in this embodiment, one symbol is composed of a maximum of 8 data. Note that, as disclosed in Patent Document 1, it is not necessary to assign signal points to all sections. However, in describing the embodiment of the present invention, transmission data is transmitted to all sections below for convenience of explanation. A description will be given assuming that (signal point) is assigned.

  FIG. 3 is a schematic diagram showing that a communication error occurs when transmission is performed using the subband mapping pattern indicated by (a) at the first time, and transmission is performed after updating to the subband mapping pattern indicated by (b) upon retransmission. Is shown. That is, at the beginning (a), the transmission data d1 to d4 are allocated to SL1, and the transmission data d7 and d8 are allocated to SL3. At the time of retransmission, the transmission data d1 and d2 are allocated to SL3, while SL3 In the example shown in FIG. 3, such as allocation of d5 to d8, the subband mapping pattern is updated so that the relationship between each section and transmission data is reversed. As a result, the error probability for each information symbol changes between the first transmission (a) and the retransmission (b). That is, according to the present embodiment, changing the subband mapping pattern for each retransmission has an effect of changing the transmission characteristics, and as a result, the interleaving effect can be effectively utilized, and the entire communication system can be effectively used. It leads to improvement of throughput.

  Next, the operation of transmitter 100 according to the present embodiment will be described using FIG. 1 and FIG. When a transmission error occurs when transmission is performed using the subband mapping pattern shown in FIG. 3A, a receiver (not shown) transmits a transmission error signal (hereinafter referred to as NACK if necessary). This NACK is detected by retransmission control information demodulation section 108 via reception antenna 106 and reception section 107. Along with this NACK detection, the subband mapping pattern determination unit 109 gives the wavelet pattern (subband mapping pattern) shown in FIG. 3B, which is a new subband mapping pattern, to the S / P conversion unit 101. The P conversion unit 101 rearranges the data according to the subband mapping pattern and outputs the data to the inverse wavelet conversion unit 102. The inverse wavelet transform unit 102 performs inverse wavelet transform on the input signal and performs parallel-serial conversion to output to the D / A converter 103. The D / A conversion unit 103 converts the input signal into an analog signal and outputs the analog signal to the transmission unit 104. The output of the transmission unit 104 is wirelessly transmitted from the transmission antenna 105, and accordingly, the receiver can receive a new subband mapping pattern.

  Next, the receiver according to Embodiment 1 will be described. FIG. 4 is a block diagram of the receiver according to the first embodiment. In FIG. 4, a receiver 400 includes a reception antenna 401, a reception unit 402, an A / D conversion unit 403, a wavelet conversion unit 404, a P / S conversion unit 405, a data demodulation unit 406, and an error determination unit. 407, a retransmission control information generation unit 408, a transmission unit 409, a transmission antenna 410, and a subband mapping pattern determination unit 411.

  In FIG. 4, the reception antenna 401 receives a transmission signal wirelessly transmitted by the transmission antenna 105 of the transmitter 100 in FIG. 1 and outputs the transmission signal to the reception unit 402. The receiving unit 402 down-converts the received radio signal and outputs it to the A / D conversion unit 403. The A / D conversion unit 403 converts the received signal into a digital signal. The converted digital signal is output to the wavelet transform unit 404. The wavelet transform unit 404 performs wavelet transform according to the subband mapping pattern (for example, the subband mapping pattern shown in FIG. 3A) from the subband mapping pattern determination unit 411. The parallel signal obtained by the wavelet transform is converted into a serial signal by the P / S converter 405 and demodulated by the data demodulator 406. The data obtained as a result of demodulation is determined by the error determination unit 407 for the presence or absence of an error. The determination result is wirelessly transmitted to the transmitter 100 in FIG. 1 via the retransmission control information generation unit 408, the transmission unit 409, and the transmission antenna 410. The subband mapping pattern information demodulated by the error determination unit 407 is output to the subband mapping pattern determination unit 411.

  Specifically, when the determination result of the error determination unit 407 is “no error”, the receiver 400 outputs the received data to an upper layer device (not shown) and indicates the determination result of “no error”. A signal (hereinafter referred to as ACK if necessary) is transmitted to the transmitter 100 in FIG.

  When NACK is transmitted, the transmitter 100 in FIG. 1 updates the subband mapping pattern from the pattern (a) in FIG. 3 to the pattern (b) as described above. As a result, the transmitter 100 wirelessly transmits to the receiver 400 the signal and the subband mapping pattern that have been inverse wavelet transformed with the new (b) pattern.

  As described above, according to the first embodiment, the transmitter 100 sequentially updates and transmits the wavelet pattern for each retransmission associated with a transmission error, so that the receiver 400 that receives this has a BER characteristic. Data can be received under different communication conditions. As a result, the receiver 400 can effectively use the interleaving effect, and can improve the throughput of the entire communication system. Further, as can be seen from the update of the wavelet pattern shown in FIG. 3, the basic structure of the wavelet pattern is not changed, only the assignment of signal points to each section is changed, that is, the subband mapping pattern is changed. Therefore, the control is simple and the wavelet pattern can be updated at a higher speed.

  In addition, the subband mapping pattern determination unit 411 that has received the subband mapping pattern information from the error determination unit 407 determines a corresponding subband mapping pattern from the subband patterns prepared in advance.

(Embodiment 2)
Next, a second embodiment according to the present invention will be described with reference to FIGS. FIG. 5 is a block diagram of transmitter 500 according to the second embodiment. 5, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 5, when a communication error occurs and retransmission is necessary, the subband pattern determination unit 509 updates the wavelet pattern. Accordingly, the transmitter 500 performs inverse wavelet transform with the new subband pattern. is there.

  FIG. 6 is a schematic diagram showing how a wavelet pattern (subband pattern) according to the second embodiment is updated. As can be seen from FIG. 6, in the transmitter 500 according to the second embodiment, it is assumed that a communication error occurs during the initial transmission using the typical wavelet pattern shown in FIG. . When this communication error is detected, it is assumed that retransmission is performed by updating the wavelet pattern and performing wavelet transformation with the pattern (b) of FIG. At the time of retransmission, as shown in the pattern (b), wavelet transformation is performed with a wavelet pattern composed only of subband level 2 (SL2: see FIG. 2). Specifically, when retransmission control is required, the subband pattern determination unit 509 outputs the subband pattern in FIG. 6B to the inverse wavelet transform unit 102 as a new wavelet pattern. Accordingly, the transmitter 500 transmits a transmission signal obtained by performing inverse wavelet transform using a new wavelet pattern and the wavelet pattern to the receiver 700 in FIG.

  FIG. 7 is a block diagram of a receiver according to the second embodiment. 7, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 7, the subband mapping pattern determination unit 711 determines a subband pattern from the demodulated subband pattern information and outputs the subband pattern to the wavelet transform unit 404. The data signal output from the A / D conversion unit 403 is wavelet transformed according to the wavelet pattern by the wavelet transformation unit 404, parallel / serial converted by the P / S conversion unit 405, demodulated by the data demodulation unit 406, and error judgment is performed. The unit 407 determines whether there is an error. The determination result is wirelessly transmitted to the transmitter 500 of FIG. 5 via the retransmission control information generation unit 408, the transmission unit 409, and the transmission antenna 410. Accordingly, if there is an error, the transmitter 500 updates the wavelet pattern and performs inverse wavelet transform with the new subband pattern.

  Specifically, a communication error occurs and transmission is performed with a new wavelet pattern from the transmitter 500 shown in FIG. A wavelet pattern signal is also transmitted from the transmitter 500 as control information. In receiver 700, subband mapping pattern determination section 711 receives demodulated subband pattern information and outputs the corresponding subband pattern to wavelet transform section 404. The wavelet transform unit 404 demodulates the retransmitted wavelet signal according to the wavelet pattern input from the subband mapping pattern determination unit 711. Along with this, wavelet transform and data demodulation are performed.

  According to the second embodiment, since transmission is performed by changing the subband pattern for each retransmission due to a transmission error, the receiver can receive data under communication conditions having different BER characteristics for each retransmission and obtain an interleaving effect. As a result, the throughput of the entire system is improved. Since the time frequency width for each subband can be changed for each retransmission, a large interleaving effect can be obtained.

(Embodiment 3)
Next, a third embodiment according to the present invention will be described. The third embodiment is characterized by the update of the wavelet pattern (subband pattern) shown in the schematic diagram of FIG. Specifically, as shown in FIG. 8, the wavelet pattern according to the third embodiment is a combination of the wavelet pattern according to the first embodiment shown in FIG. 3 and the wavelet pattern according to the second embodiment shown in FIG. Is adopted. That is, the wavelet pattern according to the third embodiment (FIG. 8B) is common to the wavelet pattern according to the second embodiment (FIG. 6B) in that the wavelet pattern is composed only of the subband level 2. Common to the wavelet pattern of the first embodiment (FIG. 3 (a), FIG. 3 (b)) in that the relation between the wavelet pattern sections and signal points is reversed between the initial transmission and the retransmission. is doing.

  Note that the transmitter and the receiver according to Embodiment 3 can be configured and realized in the same manner as in Embodiments 1 and 2, and thus will not be described in detail.

  According to the third embodiment, transmission is performed by changing the subband pattern and subband mapping pattern for each retransmission due to a transmission error, so that a larger interleaving effect can be obtained compared to the first and second embodiments. , Leading to improved throughput.

(Embodiment 4)
Next, a fourth embodiment according to the present invention will be described.

  FIG. 9 is a block diagram of transmitter 900 according to Embodiment 4 of the present invention. FIG. 10 is a block diagram of a receiver 950 according to the fourth embodiment. 9, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in FIG. 10, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  9 and 10, the transmitter 900 and the receiver 950 according to Embodiment 4 have a configuration that counts the number of retransmissions, and a wavelet pattern according to the number of retransmissions. It is characterized in that update control of (subband mapping pattern and subband pattern) is performed. However, the wavelet pattern update itself employed in the present embodiment adopts the method employed in the first to third embodiments.

  Specifically, as shown in FIG. 9, transmitter 900 includes retransmission number counting section 909 and subband pattern / subband mapping pattern determining section 910 (hereinafter abbreviated as SBP section 910 as necessary). is doing. The retransmission number counting unit 909 receives the NACK from the retransmission control information demodulation unit 108 and coefficients the number of retransmissions. The SBP unit 910 determines a wavelet pattern according to the number of retransmissions, outputs the subband mapping pattern to the S / P conversion unit 101, and outputs the subband pattern to the inverse wavelet conversion unit 102.

  FIG. 11 is a flowchart for explaining the operation of the transmitter according to the fourth embodiment. Hereinafter, the operation of the transmitter 900 will be described. Initially, as a first transmission, a transmission signal subjected to inverse wavelet transform with the wavelet pattern of FIG. 3A is transmitted from the transmitter 900 to the receiver 950 (ST101). Next, retransmission control information demodulator 108 demodulates the retransmission control information signal (ST102), and determines ACK and NACK of the transmission result (ST103). If the determination result is NACK, the number of retransmissions is counted by retransmission number counting section 909, and SBP section 910 determines a new wavelet pattern according to the number of retransmissions indicated by the count value (ST104). Specifically, according to the number of retransmissions (1) to (3), in the case of (1), control is performed to update the subband mapping pattern as shown in FIG. 3B, and in the case of (2) Control for updating only the subband shown in FIG. 6B is performed. In case of (3), update control for updating the subband pattern shown in FIG. 8B and reversing the mapping of signal points is performed.

  Next, transmitter 900 performs inverse wavelet transform with a new wavelet pattern (ST105). As a result, transmitter 900 transmits a transmission information subjected to inverse wavelet transform and a control information signal indicating that retransmission control is performed to receiver 950 (ST106).

  When there is no communication error (ST103: ACK), transmitter 900 continues communication using the previous wavelet pattern.

  FIG. 12 is a flowchart for explaining the operation of the receiver according to the fourth embodiment. Hereinafter, the operation of the receiver 950 will be described. First, receiver 950 receives a wavelet packet subjected to wavelet transform from transmitter 900 (ST151). As a result of reception, the retransmission number counting unit 951 confirms the number of retransmissions, and the subband pattern / subband mapping pattern determination unit 952 performs an operation corresponding to step ST104 in the transmitter 900, and the subband mapping pattern is changed to P / S. The subband pattern is output to conversion section 405 to wavelet conversion section 404 (ST152). Specifically, according to the number of retransmissions (1) to (3), in the case of (1), control is performed to update the subband mapping pattern as shown in FIG. 3B, and in the case of (2) Control for updating only the subband shown in FIG. 6B is performed. In case of (3), update control for updating the subband pattern shown in FIG. 8B and reversing the mapping of signal points is performed.

  Next, receiver 950 performs wavelet transform using a new wavelet pattern and demodulates received data (ST153). Next, receiver 950 determines whether there is a communication error in the received data (ST154). If there is an error, NACK is transmitted to transmitter 900 (ST154: Yes, ST155). If there is no error, receiver 950 transmits ACK to transmitter 900 (ST154: No, ST155).

  In this manner, when ACK and NACK are transmitted to the transmitter 900, the transmitter 900 performs control to update the wavelet pattern shown in FIG.

  As described above, according to the fourth embodiment, communication is performed by wavelet transform while updating a plurality of wavelet patterns according to the number of retransmissions, so that the line environment is poor and the two wavelet patterns of the first to third embodiments are used. Compared with the mode of alternately using, communication environment can be improved. Therefore, by sequentially updating the wavelet pattern, the interleaving effect can be more effectively utilized and the throughput of the communication system can be improved.

  In the fourth embodiment, the corresponding wavelet pattern is determined cyclically according to the number of retransmissions. In the first to third embodiments, the two wavelet patterns are alternately switched between the transmitter and the receiver. Since it is determined in advance, it is not necessary to transmit complicated data associated with wavelet pattern update, and the control operation is not complicated. The practicality of the communication system used is high. Of course, when constructing a communication system that is more sophisticated and requires high reliability, the cause of the communication error may be analyzed in detail and the wavelet pattern may be updated adaptively.

  In the first to fourth embodiments, a wavelet pattern is transmitted as a control information signal from a transmitter to a receiver in advance, and the control information signal is also subjected to wavelet signal modulation like a data signal. However, as a method of sending the control information signal, it is not always necessary to perform wavelet modulation. For example, even if another modulation scheme is used, transmission using another frequency channel is also possible.

  In the present invention, when multi-carrier communication is performed using the orthogonality of wavelet transform, the wavelet pattern is updated for each predetermined unit such as each symbol to be transmitted. This is useful for realizing high-throughput communication.

Block diagram of a transmitter according to Embodiment 1 of the present invention Schematic diagram showing a wavelet pattern used in the transmitter and the receiver according to Embodiment 1 of the present invention. Schematic diagram showing how the subband mapping pattern used in Embodiment 1 of the present invention is updated The block diagram of the receiver which concerns on Embodiment 1 of this invention Block diagram of a transmitter according to Embodiment 2 of the present invention The schematic diagram which shows the mode of the update of the wavelet pattern which concerns on Embodiment 2 of this invention Block diagram of a receiver according to Embodiment 2 of the present invention The schematic diagram which shows the mode of the update of the wavelet pattern which concerns on Embodiment 3 of this invention Block diagram of a transmitter according to Embodiment 4 of the present invention Block diagram of a receiver according to Embodiment 4 of the present invention Flow chart for explaining the operation of the transmitter according to the fourth embodiment of the present invention. Flow chart for explaining the operation of the receiver according to the fourth embodiment of the present invention.

Explanation of symbols

100, 500, 900 Transmitter 400, 700, 950 Receiver 102 Inverse wavelet transform unit 108 Retransmission control information demodulation unit 109 Subband mapping pattern determination unit 404 Wavelet transform unit 408 Retransmission control information generation unit 411 Subband mapping pattern determination unit 509 Subband pattern determination unit 711 Subband mapping pattern determination unit 909 Retransmission count counter 910 Subband pattern / subband mapping pattern determination unit 951 Retransmission count counter 952 Subband pattern / subband mapping pattern determination unit

Claims (6)

In the transmitter for transmitting the multiplexed transmission data by orthogonal wavelet transform and transmitting by multi-carrier communication system,
A retransmission request detection means for detecting a retransmission request from a communication partner;
When the retransmission request is detected, a wavelet pattern determination unit that updates and determines a wavelet pattern to which a plurality of signal points are assigned;
Wavelet modulation means for obtaining a multicarrier signal by performing orthogonal inverse wavelet transform on transmission data using the updated wavelet pattern;
A transmitter comprising:   2. The transmitter according to claim 1, wherein the wavelet pattern can be changed in a time axis direction and / or a frequency axis direction, and the wavelet pattern determination unit updates the wavelet pattern by the change of the division.   The transmitter according to claim 2, wherein the wavelet pattern determination unit updates the wavelet pattern by changing a signal point assigned to the section. In a receiver that receives a signal transmitted by orthogonal inverse wavelet transform,
Wavelet pattern information demodulating means for demodulating wavelet pattern information from the received signal;
Received wavelet pattern determining means for determining a wavelet pattern based on the demodulated wavelet pattern information;
A demodulating means for demodulating the signal by orthogonal wavelet transform according to the determined wavelet pattern;
A receiver comprising: In a control method for a transmitter that performs orthogonal wavelet transform on multiplexed transmission data and multiplex transmission using a multicarrier communication method,
A retransmission request detection step for detecting a retransmission request from a communication partner;
When the retransmission request is detected, a wavelet pattern determination step for updating and determining a wavelet pattern to which a plurality of signal points are assigned;
Using the updated wavelet pattern, a wavelet modulation step for obtaining a multicarrier high-frequency signal by performing orthogonal wavelet transform on transmission data;
A method for controlling a transmitter comprising: In a control method of a receiver that receives a signal transmitted by orthogonal inverse wavelet transform,
A wavelet pattern information demodulation step for demodulating wavelet pattern information from the received signal;
A received wavelet pattern determining step for determining a wavelet pattern based on the demodulated wavelet pattern information;
A demodulation step of demodulating the signal by orthogonal wavelet transform according to the determined wavelet pattern;
A control method for a receiver comprising:

Images