WO2010067524A1

WO2010067524A1 - Radio relay system, relay apparatus, transmitter apparatus, receiver apparatus, data relaying method, data transmitting method, and data receiving method

Info

Publication number: WO2010067524A1
Application number: PCT/JP2009/006423
Authority: WO
Inventors: 田中昭生
Original assignee: 日本電気株式会社
Priority date: 2008-12-11
Filing date: 2009-11-27
Publication date: 2010-06-17
Also published as: JP5477298B2; JPWO2010067524A1

Abstract

The purpose of this invention is to reduce power consumption associated with transmission path decoding and re-encoding in a radio relay station. A radio relay system comprises a radio station (1) and a relay station (2). The radio station (1) generates and transmits an RF signal (RF1) including transport data to a WPAN transmission path. The relay station (2) receives the RF signal (RF1) via the WPAN transmission path and generates and relays an RF signal (RF2) including the data received from the radio station (1) to a WWAN transmission path. The radio station (1) can exhibit, for the transport data to be transmitted to the WPAN transmission path, any one of two alternative transmission modes: one for performing a WPAN-compliant transmission path encoding and the other for performing a WWAN-compliant transmission path encoding. On the other hand, the relay station (2) can exhibit, for the encoded data received from the radio station (1), any one of two alternative relay modes: one for performing error correction code decoding and re-encoding and the other for skipping these processings.

Description

Wireless relay system, relay device, transmission device, reception device, data relay method, data transmission method, and data reception method

The present invention relates to a wireless relay system including a relay station that relays data between different wireless networks such as a WPAN (Wireless Personal Area Network) and a WWAN (Wireless Wide Area Network).

There is known a usage form in which transmission data of a portable information device is transferred to a cellular phone public network by connecting a cable between a portable information device such as a notebook PC (Personal Computer) and a cellular phone terminal.

In addition, Patent Documents 1 to 7 exist as prior documents relating to wireless or wired communication devices.

The wired communication device disclosed in Patent Document 1 detects an error in a received packet received from a LAN, and discards the received packet when a serious error such as an error exists in the information header portion. If only a minor error has occurred, the received packet is directly transferred to another LAN without discarding the packet and correcting the error.

Patent Document 2 discloses a wireless relay device for digital broadcast signals mounted on an artificial satellite. When the radio relay apparatus detects quality degradation based on the received signal level or error rate of the uplink wave, the radio relay apparatus modulates the downlink wave using a modulation scheme different from that for the uplink wave.

The relay device for optical fiber transmission disclosed in Patent Document 3 relays data having FEC (Forward Error Correction) encoded payload data and overhead data including a BIP (Bit Interleaved Parity) operation result. The relay apparatus performs only the parity check without performing the FEC decoding process on the received data, adds the check result to the overhead data, and transfers it to the next stage apparatus.

The communication device for satellite communication disclosed in Patent Document 4 determines satellite channel quality based on the quality of a received signal. Then, the communication apparatus changes the number of continuous transmissions of the transmission data packet and the user data length in the packet according to the determination result of the line quality.

Patent Document 5 discloses a relay device used for signal relay between a base station and a mobile station in a mobile radio communication system. The relay apparatus performs signal relay without performing demodulation (symbol demapping) and error correction decoding.

The packet relay device disclosed in Patent Document 6 transfers a received packet without performing error correction decoding, and simultaneously executes error correction decoding of the received packet in parallel. Then, when the downstream apparatus cannot decode the packet relay apparatus, the packet relay apparatus re-encodes the decoded packet and transmits it to the downstream apparatus.

Patent Document 7 discloses a relay device for digital data broadcasting. The relay device discards the received packet without relaying when the reception level of the received data broadcast carrier signal is reduced or when an error is detected in the error correction decoding process of the received packet.

JP 2008-17016 A JP 2006-50205 A JP 2001-186061 A Japanese Patent Laid-Open No. 06-112874 JP 2008-48237 A JP 2007-325320 A JP 2000-209273 A

The inventor of the present application has studied a form in which a wireless communication device connectable to two different wireless networks is used as a relay station. For example, there is a mobile phone terminal having a WWAN communication circuit for connecting to a mobile phone public network and a WPAN communication circuit for connecting to a WPAN. When such a mobile phone terminal and a WPAN terminal (for example, a personal computer) are connected by WPAN, the mobile phone terminal can transfer transmission data of the WPAN terminal to a base station in the WWAN (that is, a mobile phone public network). That is, the mobile phone terminal operates as a bridge that relays data between WPAN and WWAN.

Generally, the transmission path encoding method specified by WPAN and the transmission path encoding method specified by WWAN are different. Therefore, a relay station such as a mobile phone terminal receives a radio signal from an end terminal such as a WPAN terminal, performs transmission path decoding corresponding to WPAN, restores received data, and further supports WWAN for the restored data. After the transmission path encoding is performed again, it must be transmitted to the WWAN. Therefore, the relay station has a problem that power consumption required for transmission line decoding and re-encoding of data to be relayed increases.

On the other hand, the quality of the wireless transmission path is characterized by large fluctuations compared to the wired transmission path due to the fact that it is easily affected by the mobility of the terminal and interference waves. For this reason, if the transmission path decoding (error correction decoding) at the relay station is always omitted as in the optical fiber transmission relay apparatus disclosed in Patent Document 3, code errors occur frequently and effective communication is performed. May reduce speed.

Note that the packet relay apparatus disclosed in Patent Document 6 executes error correction decoding on the received packet in parallel with the received packet transfer process that omits error correction decoding. That is, it is considered that the error correction decoding for the received packet is always performed and thus does not contribute to the reduction of power consumption.

The present invention has been made based on the above-described knowledge, and aims to reduce power consumption accompanying transmission path decoding and re-encoding in a wireless relay station such as the above-described mobile phone terminal.

The wireless relay system according to the first aspect of the present invention includes a transmission device and a relay device. The transmission device generates a first radio frequency signal including transmission data and transmits the first radio frequency signal to a first radio transmission path. The relay apparatus receives the first radio frequency signal via the first radio transmission path, generates a second radio frequency signal including the transmission data, and generates a second radio transmission path. Relay transmission to.

The transmission device can be switched between the first transmission mode and the second transmission mode. Here, the first transmission mode is a mode in which transmission path encoding according to a first encoding rule is performed on the transmission data and then transmitted to the first wireless transmission path. On the other hand, in the second transmission mode, the first wireless transmission path is obtained after performing transmission path encoding on the transmission data according to a second encoding rule different from the first encoding rule. Is the mode to send to.

Furthermore, the relay device can be switched between a first relay mode corresponding to the first transmission mode and a second relay mode corresponding to the second transmission mode. The first relay mode performs transmission path decoding corresponding to the first encoding rule on the received data sequence demodulated from the first radio frequency signal, and converts the decoded data sequence to On the other hand, the transmission mode is transmitted to the second wireless transmission path after performing transmission path encoding in accordance with the second encoding rule. On the other hand, the second relay mode omits transmission path decoding corresponding to the first encoding rule and transmission path encoding according to the second encoding rule, and This is a mode for transmitting to the second wireless transmission path.

According to the first aspect of the present invention described above, it is possible to reduce power consumption accompanying transmission path decoding and re-encoding in the wireless relay device. Moreover, the 1st aspect of this invention can switch between the 1st relay mode which does not abbreviate | omit transmission path decoding and re-encoding, and the 2nd relay mode which abbreviate | omits. For this reason, for example, when the transmission line quality is low, it is possible to prevent the effective communication speed from being reduced due to frequent occurrence of code errors by selecting the first relay mode.

It is a block diagram of the radio relay system concerning embodiment of this invention. It is a block diagram regarding the short-range wireless station shown in FIG. It is a block diagram regarding the relay station shown in FIG. It is a block diagram which shows the structural example of the transmission line CODEC. It is a block diagram which shows the structural example of a WPAN transmission / reception part. It is a block diagram which shows the structural example of a WWAN radio | wireless transmission / reception part. It is a conceptual diagram which shows the signal transfer path | route of normal mode. It is a conceptual diagram which shows the signal transfer path | route in bypass mode. It is a flowchart which shows an example of the determination procedure of a communication mode change. FIG. 2 is a sequence diagram showing a data relay procedure by the wireless relay system shown in FIG. FIG. 2 is a diagram showing data transmission / reception timing in the wireless relay system shown in FIG.

Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary for the sake of clarity.

<Embodiment 1 of the Invention>
FIG. 1 shows a wireless relay system according to the present embodiment. The wireless relay system includes a short-range wireless station 1 and a relay station 2. The wireless station 1 has a WPAN interface that can be connected to the relay station 2. WPAN is a general term for short-range wireless networks having a communicable distance of about several tens of centimeters to several tens of meters. For example, WPAN includes UWB, Bluetooth (registered trademark), ZigBee, and the like whose standardization is being discussed by the IEEE 802.15 committee. The radio station 1 transmits and receives a radio frequency signal R1 including user data to and from the relay station 2.

The relay station 2 has a WPAN interface for connecting to the short-range wireless station 1 and a WWAN interface for connecting to the base station 50. WWAN is a general term for a wide area wireless network constructed by a radio access network between a base station and a mobile station and a core network generally constructed by a wired transmission path. For example, in WWAN, 3G mobile phone networks (WCDMA: Wideband CDMA, CDMA2000, LTE: Long Term Evolution) and 4G mobile phone networks (IMT-Advanced), IEEE, which are being standardized by 3GPP (Third Generation Partnership Project), IEEE Mobile WiMAX, etc. The relay station 2 relays the user data received from the wireless station 1 via the WPAN to the base station 50 on the radio frequency signal (RF2). Further, the relay station 2 relays the user data received from the base station 50 to the radio station 1 on the radio frequency signal (RF1).

In relay processing of user data, the relay station 2 omits the relay mode in which error correction decoding and re-encoding of user data is performed, and the encoded data restored from the received signal without error correction decoding and re-encoding. The relay mode for relaying can be switched. Hereinafter, the relay mode for performing error correction decoding and re-encoding is referred to as “normal mode”, and the relay mode in which these processes are omitted is referred to as “bypass mode”.

Also, in order to support switching of the relay mode of the relay station 2, the short-range wireless station 1 sets the transmission path encoding rule used for the transmission path encoding and decoding of user data to the WPAN compatible rule and the WWAN. You can switch between rules. Hereinafter, the communication mode of the wireless station 1 that performs transmission path coding and decoding using a coding rule that conforms to WPAN is referred to as a “normal mode” in association with the designation of the relay station 2 for the relay mode. On the other hand, the communication mode of the wireless station 1 that performs transmission path encoding and decoding using an encoding rule corresponding to WWAN is referred to as a “bypass mode”.

Subsequently, configuration examples of the radio station 1 and the relay station 2 corresponding to switching between the normal mode and the bypass mode will be described below with reference to FIGS. 2 to 7B.

FIG. 2 is a block diagram illustrating a configuration example of the short-range wireless station 1. In FIG. 2, a WPAN transmission line codec 10 performs transmission line encoding for transmission data and transmission line decoding for reception data based on a transmission line encoding rule suitable for WPAN. A typical example of transmission path encoding is an FEC encoding system. Known FEC coding methods include block coding, convolutional coding, a combination of these, and turbo coding as an advanced form of convolutional coding. The selection of the coding method and the coding rate is determined in consideration of various factors such as the characteristics of the wireless transmission path, the required transmission rate, and the delay tolerance.

The WWAN transmission line codec 11 performs transmission line encoding for transmission data and transmission line decoding for reception data based on a transmission line encoding rule suitable for WWAN. The main configuration of the codec 11 may be the same as that of the codec 10 described above, except that the transmission channel encoding / decoding rules are different.

The WPAN transmission / reception unit (wireless TX / RX) 12 converts the encoded data sequence encoded by the

codec

10 or 11 into a transmission symbol sequence, and multiplies the transmission symbol sequence with the carrier frequency to generate a radio frequency signal (RF1). Generate. The generated radio frequency signal is output from the antenna 13. The WPAN transmission / reception unit 12 demodulates the encoded data sequence from the radio frequency signal received by the antenna 13 and supplies the demodulated data sequence to the

codec

10 or 11.

The mode control unit 14 controls switching between the normal mode and the bypass mode. In the normal mode, user data transferred to the WWAN via the relay station 2 is encoded by the WPAN transmission line codec 11. On the other hand, in the bypass mode, user data is encoded by the WWAN transmission line codec 11. The same applies to user data received from the WWAN via the relay station 2.

Even when the bypass mode is used, the codec 10 suitable for WPAN performs encoding / decoding of control data transferred between the radio station 1 and the relay station 2 for WPAN control. Just do it. In the control data transferred between the radio station 1 and the relay station 2 for controlling the WPAN, for example, information specifying the transmission rate of the data portion, information specifying the modulation method, and information specifying the encoding method The feedback information necessary for these controls is included. For example, in the case of UWB, the encoding / decoding of the PLCP header may be performed continuously by the WPAN transmission line codec 10 even when the bypass mode is used.

FIG. 4 shows a configuration example of the transmission line codec 10 described above. The FEC encoder 1000 encodes transmission data using an FEC encoding scheme that conforms to WPAN. The FEC encoder 1000 may perform rate matching (decimation) processing in order to achieve a desired coding rate. The interleaver 1001 performs rearrangement (interleaving) of the bit order of the encoded data sequence generated by the encoder 1000. The interleaver 1001 performs interleaving according to a bit replacement rule conforming to WPAN.

The deinterleaver 1004 restores the bit order by performing reverse processing (deinterleaving) of interleaving on the encoded data sequence demodulated from the received RF signal. The error correction decoder 1003 performs error correction on the received data based on the FEC encoding performed on the transmission side, and restores the received data. The transmission path codec 10 may perform only transmission path encoding / decoding and omit interleaving / deinterleaving. Interleaving / deinterleaving is commonly employed in wireless communications to deal with burst errors, but can be omitted.

Next, a configuration example of the WPAN transmission / reception unit 12 will be described with reference to FIG. FIG. 5 shows an example of an OFDM (Orthogonal Frequency Division Multiplexing) wireless transmission / reception unit 12. Examples of WPAN that employs OFDM include UWB and wireless USB (Universal Serial Bus).

The multiplexer 1200 multiplexes the user data encoded by the

codec

10 or 11 and the control data / control channel encoded by the codec 10. The symbol mapper 1201 converts the encoded data sequence supplied from the multiplexer into a complex symbol sequence. The mapping by the symbol mapper 1201 is performed according to a modulation scheme adopted by WPAN.

The IFFT unit 1202 performs batch conversion on N symbols corresponding to a predetermined WPAN FFT size, and generates N OFDM symbols. Also, IFFT section 1202 inserts a guard interval (cyclic prefix) between the generated OFDM symbols. The OFDM symbol after insertion of the guard interval is converted into a continuous signal by the DA converter 1203 and then supplied to the quadrature modulation unit 1204.

The quadrature modulation unit 1204 multiplies the carrier frequency signal generated by the local oscillator 1206 and the baseband signal supplied from the DA converter 1203 to generate a radio frequency signal (RF1). The radio frequency signal is amplified by the transmission power amplifier 1205 and then supplied to the antenna 13.

In the signal path from the low noise amplifier 1207 to the demultiplexer 1212, a process opposite to the process for the transmission signal described above is performed on the radio frequency signal received by the antenna 13. The low noise amplifier 1207 amplifies the radio frequency signal received by the antenna 13 and supplies the amplified signal to the orthogonal demodulation unit 1208.

The orthogonal demodulation unit 1208 down-converts the received radio frequency signal to the baseband band by multiplying the received radio frequency signal with the carrier frequency signal. The down-converted received signal is sampled by the AD converter 1209 and then supplied to the FFT unit 1210.

The FFT unit 1210 performs OFDM demodulation by executing an FFT operation on the received signal after sampling, and generates a symbol string. The symbol demapper 1211 performs a determination process on the received symbol sequence generated by the FFT unit 1210 and demodulates the received data sequence. The demultiplexer 1212 separates user data and control data.

Of course, the configuration of the WPAN transmission / reception unit 12 shown in FIG. 5 is merely an example. For example, the conversion between the baseband signal and the radio frequency signal may be performed via an intermediate frequency. Of course, the WPAN transmission / reception unit 12 is not limited to the OFDM system. For example, when the WPAN adopts a DS-SS (Direct Sequence Spread Spectrum) system, the basic configuration of the WPAN transmission / reception unit 12 relating to modulation / demodulation may be the WCDMA wireless transceiver shown in FIG.

Subsequently, a configuration example of the relay station 2 will be described in detail below. FIG. 3 is a block diagram illustrating a configuration example of the relay station 2. The WPAN transmission / reception unit 21 performs wireless communication with the WPAN transmission / reception unit 12 of the wireless station 1 via the antenna 20. First, the operation in the normal mode will be described. In the normal mode, the WPAN transmission / reception unit 21 converts the encoded data sequence encoded by the codec 22 corresponding to the WPAN into a transmission symbol sequence, and multiplies the transmission symbol sequence with the carrier frequency to generate a radio frequency signal (RF1). Generate. The WPAN transmission / reception unit 21 demodulates the encoded data sequence from the radio frequency signal received by the antenna 20 and supplies the demodulated data sequence to the codec 22.

On the other hand, the operation in bypass mode is as follows. In the bypass mode, error correction decoding and re-encoding by the

codecs

23 and 22 are omitted. For this reason, the WPAN transmission / reception unit 21 receives the encoded user data demodulated by the WWAN transmission / reception unit 24 described later, and performs modulation processing. Similarly, the encoded user data demodulated from the received signal by the WPAN transmission / reception unit 21 is sent to the WWAN transmission / reception unit 24 without passing through the

codecs

22 and 23. Note that data transmission / reception between the WPAN transmission / reception unit 21 and the WWAN transmission / reception unit 24 may be performed via a data buffer (not shown) for adjustment of processing timing.

The WWAN transmission / reception unit 24 performs wireless communication with the base station 50 via the antenna 25. In the normal mode, the WWAN transmission / reception unit 24 transmits / receives encoded user data to / from the codec 23 corresponding to the WWAN. On the other hand, in the bypass mode, the encoded user data demodulated from the received signal by the WWAN transmission / reception unit 24 is sent to the WPAN transmission / reception unit 21 without passing through the

codecs

23 and 22.

Even in the case of using the bypass mode, the control data transferred between the radio station 1 and the relay station 2 for WPAN control is encoded / decoded by the codec 22 adapted to WPAN. Is called. For this reason, the encoded control data demodulated by the WPAN transmitting / receiving unit 21 is sent to the codec 22 corresponding to WPAN. Similarly, the encoded control data demodulated by the WWAN transmitting / receiving unit 24 is sent to the codec 23 corresponding to the WWAN. For example, when the WWAN is WCDMA, the control data regarding the WWAN includes a PILOT bit, a TFCI bit, an FBI bit, and the like. The TFCI bit is information indicating the number of uplink transport channels and the channel format. The FBI bit is response information related to transmission power control (TPC).

The mode control unit 26 controls switching between the normal mode and the bypass mode. A specific example of the communication mode switching determination by the mode control unit 26 will be described later.

Next, a configuration example of the WWAN transmission / reception unit 24 will be described with reference to FIG. FIG. 6 shows, as an example, a wireless transmission / reception unit 12 of the DS-SS system, specifically the WCDMA system. The multiplexer 2400 multiplexes the encoded user data and the encoded control data / control channel. The symbol mapper 2401 converts the encoded data sequence supplied from the multiplexer 2400 into a complex symbol sequence. The mapping by the symbol mapper 2401 is performed according to the primary modulation scheme of WCDMA.

The spreading unit 2402 performs spreading modulation by multiplying the symbol sequence generated by the symbol mapper 2401 by the spreading code. The symbol sequence after the spread modulation is converted into a continuous signal by the DA converter 2403 and then supplied to the quadrature modulation unit 2404.

The quadrature modulation unit 2404 multiplies the carrier frequency signal generated by the local oscillator 2406 and the baseband signal supplied from the DA converter 2103 to generate a radio frequency signal (RF2). The radio frequency signal is amplified by the transmission power amplifier 2405 and then supplied to the antenna 25.

In the signal path from the low noise amplifier 2407 to the demultiplexer 2412, the radio frequency signal received by the antenna 25 is subjected to a process opposite to the process for the transmission signal described above. The low noise amplifier 2407 amplifies the radio frequency signal received by the antenna 25 and supplies the amplified signal to the quadrature demodulation unit 2408.

The orthogonal demodulator 2408 multi-converts the received radio frequency signal with the carrier frequency signal to down-convert it to the baseband band. The down-converted received signal is sampled (that is, code determination) by the AD converter 2409 and then supplied to the despreading unit 2410.

The despreading unit 2410 performs a despreading process on the baseband signal sampled by the AD converter 2409 to generate a received symbol sequence. The despreading unit 2410 is configured using, for example, a matched filter. The symbol demapper 2411 performs a determination process on the received symbol sequence generated by the despreading unit 2410 and demodulates the received data sequence. The demultiplexer 2412 separates user data and control data.

7A and 7B are conceptual diagrams showing signal transfer paths when user data transmitted from the short-range wireless station 1 is transferred to the base station 50 in each of the normal mode and the bypass mode. As shown in FIG. 7A, in the normal mode, the relay station 2 executes transmission path decoding corresponding to WPAN and re-encoding corresponding to WWAN. On the other hand, in the bypass mode shown in FIG. 7B, these channel decoding and re-encoding are omitted.

As described above, the relay station 2 according to the present embodiment can omit transmission line decoding and re-encoding for user data to be relayed. For this reason, the power consumption accompanying transmission path decoding and re-encoding can be reduced. Further, the relay station 2 can switch between a normal mode that does not omit transmission path decoding and re-encoding and a bypass mode that is omitted. For example, the relay station 2 may select the normal mode when the transmission path quality in the WPAN section is low. Thereby, it is possible to prevent the effective communication speed from being lowered due to frequent code errors in the WPAN section.

Subsequently, the change process between the normal mode and the bypass mode will be described below with reference to FIGS. FIG. 8 is a flowchart showing a specific example of the mode change determination by the

mode control units

14 and 26. In step S101, the mode control unit 14 (26) acquires the transmission path quality of the WPAN section. For example, in the case of the wireless station 1, the transmission path quality includes RSSI (Received Signal Strength Indicator) obtained by the orthogonal demodulator 1208 or AD converter 1209, LQI (Link Quality Quality Indicator) obtained by the symbol demapper 1211, WPAN transmission channel codec. The code error rate (BER: Bit Error Rate) obtained at 10 may be acquired. Note that the measurement of the transmission path quality may be performed not only on one of the above-described RSSI, LQI, and BER but also on two or more indicators.

In step S102, the mode control unit 14 (26) determines whether or not the transmission path quality level exceeds a predetermined threshold value. If the quality level exceeds the threshold and is good, the mode control unit 14 (26) determines to change to the bypass mode (S103). On the other hand, when the transmission path quality level does not satisfy the standard (below the threshold), the mode control unit 14 (26) determines to change to the normal mode (S104). The transmission path quality described above generally has a correlation with the communication distance in the WPAN section. For this reason, it can be paraphrased that the determination in step S102 is determining the communication distance (proximity) between the radio station 1 and the relay station 2.

The determination process shown in FIG. 8 may be performed on the device side that receives the radio signal propagated through the WPAN transmission path. For example, in the uplink direction from the radio station 1 to the relay station 2, the mode control unit 26 of the relay station 2 may measure the channel quality and perform the mode change determination. Further, in the downlink direction from the relay station 2 to the radio station 1, the mode control unit 14 of the radio station 1 may measure the channel quality and perform the mode change determination.

Further, the mode change determination may be performed intensively by either the radio station 1 or the relay station 2. For example, if the mode control unit 14 of the wireless station 1 performs intensively, the relay station 2 may transmit the measurement result of the transmission path quality to the wireless station 1. Further, the mode control unit 14 of the radio station 1 may switch the normal mode to the bypass mode together in the downlink direction and the uplink direction when the quality of the downlink transmission path is good.

Next, the operation when the uplink data transmission from the radio station 1 to the relay station 2 is switched from the normal mode to the bypass mode will be specifically described with reference to FIGS. FIG. 9 is a sequence diagram showing the interaction between the short-range radio station 1 and the relay station 2. FIG. 10 is a diagram showing data transmission / reception timing corresponding to FIG. Reference numerals 201TX / RX to 208TX / RX related to data transmission / reception correspond to each other in FIG. 9 and FIG. 9 and 10, “TX” means data transmission, and “RX” means data reception.

9, WPAN beacons 201 and 202 are transmitted and received between the wireless station 1 and the relay station 2 in the normal mode. Next, the wireless station 1 transmits the data 203 encoded according to the WPAN transmission path encoding rule to the relay station 2. Next, at timing 204, the relay station 2 determines whether or not the mode can be changed to the bypass mode based on the data reception result from the radio station 1. Next, the relay station 2 transmits the data 205 encoded according to the WWAN transmission path encoding rule to the base station 50.

When the change to the bypass mode is determined at timing 204, the relay station 2 transmits a data transmission permission 206 by WWAN encoding to the wireless station 1. The wireless station 1 that has received the data transmission permission 206 by WWAN encoding encodes user data according to the WWAN transmission path encoding rule, and transmits this data 207 to the relay station 2. The relay station 2 transmits the encoded data 207 received from the wireless station 1 to the base station 50 in the bypass mode (data 208).

According to the mode change example described with reference to FIGS. 8 to 10, the communication mode can be changed according to the quality level of the WPAN transmission line. By making a transition to the bypass mode on condition that the quality level of the WPAN transmission line satisfies a predetermined standard, the use of the bypass mode can be limited to a case where the quality of the WPAN transmission line is good. The case where the WPAN transmission path quality is good is, for example, a case where the radio station 1 and the relay station 2 are arranged sufficiently close to each other. Thereby, the radio station 1 and the relay station 2 can prevent the effective communication speed from being lowered due to the occurrence of an error in the WPAN section.

Incidentally, the mode change determination process by the

mode control units

14 and 26 described above may be realized using a semiconductor processing apparatus such as an ASIC or a DSP. The mode change determination process may be realized as an ASIC or DSP common to the wireless transmission /

reception units

12, 21, or 24 and the

codecs

10, 11, 22, or 23.

Further, the mode change determination process may be realized by causing a computer such as a microprocessor to execute a control program describing the determination procedure described with reference to FIG. This control program can be stored in various types of storage media, and can be transmitted via a communication medium. Here, the storage medium includes, for example, a flexible disk, a hard disk, a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD, a ROM cartridge, a RAM memory cartridge with battery backup, a flash memory cartridge, a nonvolatile RAM cartridge, and the like. . In addition, the communication medium includes a wired communication medium such as a telephone line, a wireless communication medium such as a microwave line, and the Internet.

<Other embodiments>
In the first embodiment of the present invention described above, the configuration example in which the radio station 1 and the relay station 2 can be switched to the bypass mode in both directions has been described. However, switching between the normal mode and the bypass mode may be performed only in one of the upward direction and the downward direction.

In the first embodiment of the present invention described above, the case where the relay station 2 performs data relay between the WPAN and the WWAN has been described. However, the combination of networks in which the relay station 2 relays data is not particularly limited. For example, the relay station 2 may perform data relay between WPAN and WLAN. Further, the relay station 2 may perform data relay between the WLAN and the WWAN.

The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

This application claims priority based on Japanese Patent Application No. 2008-315240 filed on Dec. 11, 2008, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 1 Near field station 2 Relay station 10 WPAN transmission line codec 11 WWAN transmission line codec 12 WPAN transmission / reception part 13 Antenna 14 Mode control part 20 Antenna 21 WPAN transmission / reception part 22 WPAN transmission line codec 23 WWAN transmission line codec 24 WWAN wireless transmission / reception part 25 Antenna 26 Mode control unit 50 Base station 1000 FEC encoder 1001 Interleaver 1002 Deinterleaver 1003 Error correction decoder 1200 Multiplexer 1201 Symbol mapper 1202 IFFT unit 1203 DA converter 1204 Orthogonal modulation unit 1205 Transmission power amplifier 1206 Local oscillator 1207 Low noise amplifier 1208 Orthogonal demodulation unit 1209 AD converter 1210 FFT unit 1211 Symbol demapper 1212 Demultiplexer 240 Multiplexer 2401 symbol mapper 2402 spreading unit 2403 DA converter 2404 quadrature modulation unit 2405 of the transmission power amplifiers 2406 a local oscillator 2407 low-noise amplifier 2408 quadrature demodulator 2409 AD converter 2410 despreading unit 2411 symbol demapper 2412 demultiplexers

Claims

A transmitter for generating a first radio frequency signal including transmission data and transmitting the first radio frequency signal to the first radio transmission path;
A relay device that receives the first radio frequency signal via the first radio transmission path, generates a second radio frequency signal including the transmission data, and relays the second radio frequency signal to the second radio transmission path; With
The transmitter is switchable between a first transmission mode and a second transmission mode;
The first transmission mode is a mode for transmitting to the first wireless transmission path after performing transmission path encoding on the transmission data according to a first encoding rule,
In the second transmission mode, transmission channel encoding is performed on the transmission data according to a second encoding rule different from the first encoding rule, and then transmitted to the first wireless transmission channel. Mode to
The relay device is switchable between a first relay mode corresponding to the first transmission mode and a second relay mode corresponding to the second transmission mode;
The first relay mode performs transmission path decoding corresponding to the first encoding rule on the received data sequence demodulated from the first radio frequency signal, and converts the decoded data sequence to A mode for transmitting to the second wireless transmission path after performing transmission path encoding according to the second encoding rule for
In the second relay mode, transmission path decoding corresponding to the first encoding rule and transmission path encoding according to the second encoding rule are omitted, and the received data string is changed to the second relay mode. Is a mode to transmit to the wireless transmission path of
Wireless relay system.
2. The wireless relay system according to claim 1, wherein the relay device switches from the first relay mode to the second relay mode when the first wireless transmission path satisfies a predetermined quality level. 3. .
The wireless relay system according to claim 2, wherein the transmission device switches between the first transmission mode and the second transmission mode in response to switching of the relay mode in the relay device.
The transmission device according to any one of claims 1 to 3, wherein the transmission device switches from the first transmission mode to the second transmission mode when the first wireless transmission path satisfies a predetermined quality level. The wireless relay system according to item.
The wireless relay system according to claim 4, wherein the relay device switches between the first relay mode and the second relay mode in response to switching of a transmission mode in the transmission device.
In the second transmission mode, the transmission apparatus transmits a transmission line code according to the first encoding rule for control data transmitted to the relay apparatus for controlling the first wireless transmission line. The wireless relay system according to any one of claims 1 to 5, wherein the communication is continued.
In the second relay mode, the relay apparatus performs transmission path decoding according to the first encoding rule for control data received from the transmission apparatus for controlling the first wireless transmission path. The wireless relay system according to any one of claims 1 to 6, wherein the communication is continued.
When the communication distance between the transmission device and the relay device is equal to or less than a predetermined distance, the transmission device and the relay device can change the second transmission mode from the first transmission mode and the first relay mode. The wireless relay system according to any one of claims 1 to 7, wherein transition is made to each of the transmission mode and the second relay mode.
The transmitter is
First encoding means for selectively encoding the transmission data using the first or second encoding rule;
First mapping means for converting a first encoded data sequence that has been transmission-line encoded by the first encoding means into a first transmission symbol sequence;
First radio transmission means for generating the first radio frequency signal by multiplying the first transmission symbol string with a first carrier wave and transmitting the first radio frequency signal to the first radio transmission path;
The relay device is
Receiving means for extracting a received symbol sequence from the first radio frequency signal received via the first radio transmission path;
Demapping means for demodulating the received data sequence from the received symbol sequence;
Decoding means for performing transmission path decoding corresponding to the first encoding rule on the received data sequence and restoring the transmission data;
Second encoding means for performing transmission path encoding on the transmission data restored by the decoding means in accordance with the second encoding rule;
One of the second encoded data sequence that has been channel-coded by the second encoding unit and the received data sequence demodulated by the demapping unit is selectively input, and the input data sequence Second mapping means for converting a second transmission symbol sequence corresponding to the second wireless transmission path;
Second radio transmission means for generating the second radio frequency signal by multiplying the second transmission symbol string with a second carrier wave and transmitting the second radio frequency signal to the second radio transmission path;
When the first encoding unit performs transmission path encoding according to the first encoding rule, the second mapping unit generates the second transmission symbol sequence from the second encoded data sequence. And
When the first encoding means performs transmission path encoding according to the second encoding rule, the second mapping means generates the second transmission symbol string from the received data string;
The wireless relay system according to any one of claims 1 to 8.
10. The wireless relay system according to claim 1, wherein the relay device is a mobile phone terminal.
The first wireless communication path is a wireless PAN (Personal Area Network) or a wireless LAN (Local Area Network),
The wireless relay system according to any one of claims 1 to 10, wherein the second wireless communication path is a wireless communication network capable of far-distance communication with respect to the first wireless communication path.
The first encoding rule, the first mapping means, the first wireless transmission means, the receiving means, and the demapping means are adapted to UWB (Ultra Wide Band),
The second encoding rule, the second mapping unit, and the second wireless transmission unit are adapted to at least one of wireless LAN, mobile WiMAX, W-CDMA, CDMA2000, LTE, and IMT-Advanced. The wireless relay system according to any one of claims 1 to 10.
A first radio frequency signal is received via the first radio transmission path, and a second radio frequency signal including transmission data included in the first radio frequency signal is generated to generate a second radio frequency signal. A relay device for relay transmission to the transmission line;
A receiver that receives the second radio frequency signal via the second radio communication path,
The relay device is switchable between a first relay mode and a second relay mode;
In the first relay mode, transmission line decoding corresponding to the first encoding rule is performed on the received data sequence demodulated from the first radio frequency signal, and the data sequence after decoding is performed. A mode of transmitting to the second wireless transmission path after performing transmission path encoding according to a second encoding rule different from the first encoding rule,
In the second relay mode, transmission path decoding corresponding to the first encoding rule and transmission path encoding according to the second encoding rule are omitted, and the received data string is changed to the second relay mode. Mode to transmit to the wireless transmission path of
The receiver is switchable between a first reception mode corresponding to the first relay mode and a second reception mode corresponding to the second relay mode;
The first reception mode is a mode in which the transmission data is restored by performing transmission path decoding corresponding to the second encoding rule on the data sequence demodulated from the second radio frequency signal. And
The second reception mode is a mode in which the transmission data is restored by performing transmission path decoding corresponding to the first encoding rule on the data sequence demodulated from the second radio frequency signal. ,
Wireless relay system.
When the second wireless transmission path satisfies a predetermined quality level, the receiving device and the relay device can change the second reception mode and the first reception mode from the first reception mode and the first relay mode. The wireless relay system according to claim 13, wherein the wireless relay system transitions to a second relay mode.
The wireless relay system according to claim 13 or 14, wherein the reception device switches between the first reception mode and the second reception mode in response to switching of the relay mode in the relay device.
The wireless device according to any one of claims 13 to 15, wherein the relay device performs switching between the first relay mode and the second relay mode in response to switching of a reception mode in the reception device. Relay system.
In the second reception mode, the receiving apparatus performs transmission path decoding corresponding to the second encoding rule for control data received from the relay apparatus for controlling the second wireless transmission path. The wireless relay system according to any one of claims 13 to 16, wherein the communication is continued.
In the second relay mode, the relay apparatus transmits a transmission line code according to the second encoding rule for control data transmitted to the reception apparatus for controlling the second wireless transmission line. The wireless relay system according to any one of claims 13 to 17, wherein the communication is continued.
A first radio frequency signal is received via the first radio transmission path, and a second radio frequency signal including transmission data included in the first radio frequency signal is generated to generate a second radio frequency signal. A relay device that relays and transmits to a transmission line,
Relay means capable of switching between the first relay mode and the second relay mode;
Control means for controlling switching between the first and second relay modes,
In the first relay mode, transmission line decoding corresponding to the first encoding rule is performed on the received data sequence demodulated from the first radio frequency signal, and the data sequence after decoding is performed. A mode of transmitting to the second wireless transmission path after performing transmission path encoding according to a second encoding rule different from the first encoding rule,
In the second relay mode, transmission line decoding corresponding to the first encoding rule and transmission line encoding according to the second encoding rule are omitted, and the received data string is changed to the second relay mode. It is a mode to transmit to the wireless transmission path of
Relay device.
In the second relay mode, the relay means performs transmission path decoding according to the first encoding rule for control data related to the first wireless transmission path included in the first radio frequency signal. The relay apparatus according to claim 19, wherein the relaying is continued.
The relay means is
Receiving means for extracting a received symbol sequence from the first radio frequency signal;
Demapping means for demodulating a received data sequence from the received symbol sequence;
Decoding means for performing transmission path decoding corresponding to the first encoding rule on the received data sequence and restoring the transmission data;
Encoding means for performing transmission path encoding on the transmission data restored by the decoding means according to the second encoding rule;
Either one of the encoded data sequence that has been transmission path encoded by the encoding unit and the received data sequence demodulated by the demapping unit is selectively input, and the input data sequence is input to the second radio Mapping means for converting to a transmission symbol sequence corresponding to the transmission path;
Wireless transmission means for generating the second radio frequency signal by multiplying the transmission symbol string with a carrier wave and transmitting the second radio frequency signal to the second radio transmission path;
With
The control means switches which of the encoded data sequence and the received data sequence is used for generation of the transmission symbol sequence,
The relay device according to claim 19 or 20.
The relay apparatus according to claim 21, wherein the control means determines a data sequence used for generating the transmission symbol sequence according to a quality level of the first or second wireless transmission path.
The relay according to claim 21, wherein the control means determines a data sequence to be used for generating the transmission symbol sequence in response to switching of a communication mode of a communication partner device in the first or second wireless transmission path. apparatus.
A transmission device that generates a radio frequency signal including transmission data and transmits the signal to a wireless transmission path,
Transmission means switchable between a first transmission mode and a second transmission mode;
Control means for controlling switching between the first and second transmission modes,
The first transmission mode is a mode for transmitting to the wireless transmission path after performing transmission path encoding on the transmission data according to a first encoding rule,
The second transmission mode is a mode in which transmission channel encoding according to a second encoding rule different from the first encoding rule is performed on the transmission data and then transmitted to the wireless transmission channel. Yes,
The control means determines which of the first and second encoding rules to encode the transmission data according to the quality level of the wireless transmission path.
Transmitter device.
In the second transmission mode, the transmission means performs transmission path encoding according to the first encoding rule for control data transmitted to the wireless transmission path for controlling the wireless transmission path. The transmission device according to claim 24, which continues.
The transmission means includes
Encoding means capable of performing transmission path encoding on transmission data in accordance with the first or second encoding rule;
Mapping means for converting the encoded data sequence generated by the encoding means into a transmission symbol sequence;
A wireless transmission means for generating a radio frequency signal by multiplying the transmission symbol sequence with a carrier wave and transmitting the signal to a wireless transmission path;
The transmission device according to claim 24 or 25.
The first encoding rule, the mapping unit, and the wireless transmission unit are adapted to a wireless PAN (Personal Area Network) or a wireless LAN (Local Area Network),
The transmission device according to any one of claims 24 to 26, wherein the second encoding rule is adapted to a wireless communication network capable of long-distance communication through the wireless transmission path.
The first encoding rule, the mapping unit, and the wireless transmission unit are adapted to UWB (Ultra Wide band),
The transmission according to any one of claims 24 to 26, wherein the second coding rule is adapted to at least one of wireless LAN, mobile WiMAX, W-CDMA, CDMA2000, LTE, and IMT-Advanced. apparatus.
A receiving device that receives a radio frequency signal via a wireless communication path,
Receiving means switchable between a first receiving mode and a second receiving mode;
Control means for controlling switching between the first and second reception modes,
The first reception mode is a mode in which transmission data is restored by performing transmission path decoding corresponding to a first encoding rule on a data sequence demodulated from the radio frequency signal,
In the second reception mode, transmission data is obtained by performing transmission path decoding corresponding to a second encoding rule different from the first encoding rule on the data sequence demodulated from the radio frequency signal. Is the mode to restore
The control means determines according to the quality level of the wireless transmission path whether to perform transmission path decoding corresponding to the first or second decoding rule,
Receiver device.
In the second reception mode, the receiving unit continues transmission path decoding corresponding to the first encoding rule for control data related to the first wireless transmission path included in the radio frequency signal. The receiving device according to claim 29.
The receiving means includes
Radio receiving means for extracting a received symbol sequence from the radio frequency signal received via the radio transmission path;
Demapping means for demodulating a received data sequence from the received symbol sequence;
Decoding means for performing transmission path decoding corresponding to the first or second encoding rule on the received data sequence to restore transmission data;
The receiving device according to claim 29 or 30, comprising:
The first encoding rule, the receiving unit, and the demapping unit are adapted to a wireless PAN (Personal Area Network) or a wireless LAN (Local Area Network),
The receiving apparatus according to any one of claims 29 to 31, wherein the second encoding rule is adapted to a wireless communication network capable of long-distance communication through the wireless transmission path.
The first encoding rule, the receiving unit, and the demapping unit are adapted to UWB (Ultra Wide band),
The reception according to any one of claims 29 to 31, wherein the second coding rule is adapted to at least one of wireless LAN, mobile WiMAX, W-CDMA, CDMA2000, LTE, and IMT-Advanced. apparatus.
A relay that receives a first radio frequency signal including transmission data via the first radio transmission path, generates a second radio frequency signal including the transmission data, and relays the second radio frequency signal to the second radio transmission path A device data relay method,
Comprising switching from the first relay mode to the second relay mode,
In the first relay mode, transmission line decoding corresponding to the first encoding rule is performed on the received data sequence demodulated from the first radio frequency signal, and the data sequence after decoding is performed. A mode of transmitting to the second wireless transmission path after performing transmission path encoding according to a second encoding rule different from the first encoding rule,
In the second relay mode, transmission path decoding corresponding to the first encoding rule and transmission path encoding according to the second encoding rule are omitted, and the received data string is changed to the second relay mode. It is a mode to transmit to the wireless transmission path of
Data relay method.
35. The method further comprises determining switching from the first relay mode to the second relay mode when the first or second wireless transmission path satisfies a predetermined quality level. The method described in 1.
The method further comprises the step of determining switching from the first relay mode to the second relay mode in response to switching of the communication mode of the communication partner device in the first or second wireless transmission path. 34. The method according to 34.
A data transmission method by a transmission device that generates a radio frequency signal including transmission data and transmits the signal to a wireless transmission path,
Determining switching from the first transmission mode to the second transmission mode according to the quality level of the wireless transmission path;
Based on the determination, comprising switching from a first transmission mode to a second transmission mode;
The first transmission mode is a mode for transmitting to the first wireless transmission path after performing transmission path encoding on the transmission data according to a first encoding rule,
In the second transmission mode, transmission channel encoding is performed on the transmission data according to a second encoding rule different from the first encoding rule, and then transmitted to the first wireless transmission channel. Is the mode to
Data transmission method.
A data receiving method by a receiving device that receives a radio frequency signal via a short-range wireless communication path,
Determining switching from the first reception mode to the second reception mode according to the quality level of the wireless transmission path;
Based on the determination, comprising switching from a first reception mode to a second reception mode;
The first reception mode is a mode in which transmission data is restored by performing transmission path decoding corresponding to a first coding rule for a data sequence demodulated from the radio frequency signal,
In the second reception mode, transmission data is obtained by performing channel decoding corresponding to a second encoding rule different from the first encoding rule on a data sequence demodulated from the radio frequency signal. Is the mode to restore,
Data reception method.