WO2006106676A1

WO2006106676A1 - Transmitting apparatus and receiving apparatus

Info

Publication number: WO2006106676A1
Application number: PCT/JP2006/306302
Authority: WO
Inventors: Mamoru Sawahashi; Kenichi Higuchi; Hiroyuki Atarashi
Original assignee: Ntt Docomo, Inc.
Priority date: 2005-04-01
Filing date: 2006-03-28
Publication date: 2006-10-12
Also published as: JP2006287759A; TWI301364B; TW200703991A; JP4531614B2

Abstract

A transmitting apparatus can be used in a first communication system of single-carrier format and a second communication system of multicarrier format. This apparatus comprises a first retransmitting means that transmits a single-carrier packet via a downstream channel and retransmits the single-carrier packet in response to a request after the lapse of a first retransmission standby interval; and a second retransmitting means that transmits a multicarrier packet via the downstream channel and retransmits the multicarrier packet in response to a request after the lapse of a second retransmission standby interval. The second retransmitting means transmits at least one multicarrier packet during the first retransmission standby interval.

Description

Specification

Transmitting apparatus and receiving apparatus

Technical field

TECHNICAL FIELD [0001] The present invention relates to a technical field of wireless communication, and more particularly to a transmission device and a reception device that enable coexistence of a single carrier system and a multicarrier system.

Background art

[0002] Third-generation communication systems represented by IMT-2000 (International Mobile Telecommunications-2000), in particular, require a high-speed and large-capacity downlink, and as an example, using a frequency band of 5MHz, 2Mbps or more The information transmission rate is realized. In IMT-2000, a single-carrier wideband code division multiple access (W-CDMA: Wideb and CDMA) system is adopted. Also, a method called high speed downlink packet access (HSDPA) is adopted. HSDP A employs an adaptive modulation and channel coding (AMC) method, an automatic repeat request (ARQ) method for packets in the MAC layer, and the like, thereby enabling a high transmission rate. Nya is aiming for high quality.

[0003] On the other hand, research on multi-carrier systems using a plurality of subcarriers is also currently underway. In particular, the Orthogonal Frequency and Code Division Multiplexing (OFCDM) scheme is promising for future communication systems. The OFCDM method transmits data in parallel on a number of low-speed subcarriers and performs two-dimensional spreading in the frequency and time domains to further increase the speed and quality.

[0004] A publicly known example relating to a communication system in which single carrier terminals and multicarrier terminals can be mixed is described in Patent Document 1, for example.

Patent Document 1: 2004-72455

Disclosure of the invention

Problems to be solved by the invention

Therefore, instead of or in place of a W-CDMA system (referred to as an old system for convenience). In addition, it is conceivable to provide OFCDM system services (referred to as a new system for convenience). In this case, it is expected that multiple areas will exist in which the old and new systems coexist. Even if the new system is changed to the old system, there will be a period of coexistence of both systems, at least in the transition period. One approach to coexisting the old and new systems is to assign separate frequency bands to the old and new systems, as shown in Figure 1A. In Figure 1A, four 5 MHz bands are prepared, two are allocated to the old system operator (carrier), and the other two are allocated to the new system operator. Such a technique is advantageous if there remains a newly assignable band in the frequency band. The above patent document also presupposes such a convenient band.

[0006] However, depending on the region, time, or country, it may not be possible to allocate such a frequency band separately. For example, as shown in Figure 1B, the frequency band is entirely used by the old system. Figure 1B shows two 5MHz bands, both of which have been allocated to the old system operator. In the situation shown in Fig. 1B, it is technically possible to open one of the two bands and assign it to the operator of the new system. However, this is not always possible. For example, if the resource power Si provider has only a 5 MHz band, it is difficult to allocate such a frequency band.

[0007] The present invention has been made in view of the above problems, and the problem is that at least a part of the first communication system of the single carrier system and the second communication system of the multicarrier system are used. The present invention provides a transmission device and a reception device that can coexist while sharing a frequency band.

Means for solving the problem

[0008] In the present invention, a transmission apparatus that can be used in the first communication system of the single carrier scheme and the second communication system of the multicarrier scheme is used. This apparatus transmits a single carrier packet on a downlink channel, and after the first retransmission waiting period has elapsed, a first retransmission means for resending the single carrier packet on demand, and a multicarrier packet on the downlink channel Transmit and after the second retransmission waiting period elapses Second retransmitting means for retransmitting the packet. The second retransmission means transmits one or more multi-carrier packets during the first retransmission waiting period.

The invention's effect

[0009] According to the present invention, the first communication system of the single carrier system and the second communication system of the multi carrier system can share at least some frequency bands in the same region. Brief Description of Drawings

FIG. 1A is a diagram showing an example of a frequency band.

FIG. 1B is a diagram showing an example of a frequency band.

FIG. 2 shows an overall view of a transmitter according to an embodiment of the present invention.

FIG. 3 is a diagram showing details of first and second baseband processing units according to an embodiment of the present invention.

FIG. 4 is a diagram showing frequency spectra of signals used in the first and second communication systems.

FIG. 5 shows a conceptual diagram of a packet transmitted by the transmitter of FIGS.

FIG. 6 is a diagram showing another mode of transmitting a packet.

FIG. 7 is a diagram showing details of first and second baseband processing units according to an embodiment of the present invention.

FIG. 8 shows a conceptual diagram of a packet transmitted from the transmitter according to the present embodiment.

FIG. 9 is a diagram showing details of a baseband processing unit according to an embodiment of the present invention.

FIG. 10 shows a transmitter in which the processing elements are made more common than the baseband processing unit shown in FIG.

FIG. 11 is an overall view of a receiver according to an embodiment of the present invention.

FIG. 12 shows details of the first baseband processing unit in FIG. 11.

FIG. 13 shows details of the second baseband processing section in FIG. 11.

FIG. 14 shows a baseband processing unit of a receiver according to an embodiment of the present invention.

[FIG. 15] A block diagram of a spreading unit used in a VSCRF—CDMA transmitter.

FIG. 16 shows a block diagram of a despreading unit used in a VSCRC-CDMA receiver.

FIG. 17 is an explanatory diagram relating to main operations in the VSCRF-CDMA system. Explanation of symbols

201, 202 First and second baseband processing units; 204 multiplexing unit; 206 RF transmission unit; 2 10 digital-to-analog conversion unit; 212 quadrature modulator; 214 local oscillator; 216 band-pass filter; 218 mixer; 222 bandpass filter; 2 24 power amplifier;

302 convolutional encoder; 304 data modulation unit; 306, 308 spreading unit; 310 multiplexing unit; 312 band-limiting filter; 322 turbo encoder; 324 data modulator; 326 spreading unit; 330 multiplexing unit; 334 transmission TTI control unit; 34 2 turbo encoder; 344 data modulator; 345 interleaver; 347 serial-parallel conversion unit; 349 spreading unit; 350 fast inverse Fourier transform unit; 352 guard interval insertion unit; 354 transmission TTI control unit ;

362 convolutional encoder 364 data modulator 365 interleaver 365; 367 series-parallel conversion unit; 369 spreading unit multiplexing unit 348;

902 interleaver; 904 fast Fourier transform unit; 906 band limiting filter;

1102 RF receiver; 1111, 1112 1st and 2nd base node processor; 1103 Low noise amplifier; 1104 Mixer; 1105 Local oscillator; 1106 Bandpass filter; 1 107 Automatic gain controller; 1108 Quadrature detector; 1109 Local Oscillator; 1110 Analog to digital converter;

1202 Band-limiting filter; 1204 Nosser; 1206 Despreading unit; 1208 Channel estimation unit; 1210 Lake synthesis unit 1210; 1212 synthesis unit; 1214 Turbo decoder;

1302 Symbol timing detection unit; 1304 Guard internal removal unit; 1306 Fast Fourier transform unit; 1308 Demultiplexer; 1310 Channel estimation unit; 1312 Despreading unit; 1314 Parallel-serial conversion unit; 1316 Despreading unit; 1318, 1319 Combining unit 1320 Dintarino 1322 Turbo encoder 1324 Viterbi decoder

1402 Demultiplexer; 1403 Band-limiting filter; 1404 Fast inverse Fourier transform unit;

1602 Spreading unit; 1612, 1614 Multiplying unit; 1604 Iterative synthesis unit; 1606 Phase shift Part;

1702 Phase shift part; 1704 Iterative synthesis part; 1706 Despreading part;

1802 Data sequence before compression; 1804 Compressed and repeated data sequence; 1806 Uplink frequency spectrum for all mobile stations

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] According to one aspect of the present invention, a single carrier packet is retransmitted in response to a request after the first retransmission waiting period has elapsed. Multi-carrier packets are also retransmitted upon request after the second retransmission wait period. One or more multicarrier packets are transmitted during the first retransmission wait period. Since single carrier packets and multicarrier packets are transmitted in different time slots, both signals are transmitted without interfering with each other. Coexistence of both systems can be realized by transmitting other system packets in addition to the same system packets within the first retransmission waiting period. Therefore, for example, even if there is no unallocated band as shown in Fig. 1 (B), the OFCDM system can coexist in the same region using the existing W-CDMA band. wear. In addition, since the packet is not retransmitted later than the first retransmission waiting period for the first communication system, even if the new second communication system coexists, the old first communication The system can be operated as before.

[0013] According to one aspect of the present invention, the transmission time interval of a single carrier packet is equal to the transmission time intervals of a plurality of multicarrier packets. One single-carrier packet and multiple multi-carrier packets are sent alternately.

[0014] According to one aspect of the present invention, the control channel power of the first communication system is shared by the first and second communication systems. The control channel is transmitted continuously in time. Thereby, resources can be saved.

[0015] According to an aspect of the present invention, the first control channel for the first communication system and the second control channel for the second communication system are transmitted separately. In addition, the first control channel is transmitted together with the single carrier packet, and the second control channel is transmitted together with the multicarrier packet. As a result, inter-system interference can be greatly reduced. According to one aspect of the present invention, means for Fourier transforming a signal representing a single carrier packet, filter means for band-limiting the signal after Fourier transformation, a signal after band limitation, and a multicarrier signal The transmission apparatus further includes means for time-multiplexing a signal representing a packet and means for performing inverse Fourier transform on the time-multiplexed signal. As a result, elements related to transmission of the first and second communication systems can be shared. In addition, by performing bandwidth limitation on cinder carrier packets in the frequency domain, the computational burden required for bandwidth limitation processing can be reduced.

[0017] According to an aspect of the present invention, the transmission apparatus further includes an encoding unit that selects and encodes one of signals representing single carrier or multicarrier packets. As a result, the encoding means can be shared by both systems.

[0018] According to one aspect of the present invention, a transmitter usable in a first communication system using a single carrier scheme and a second communication system using a multicarrier scheme performs Fourier transform on a signal representing a single carrier packet. Then, when the bandwidth is limited, time-multiplexed with a signal representing a multi-carrier packet, and the multiplexed signal is transmitted after inverse Fourier transform, the receiving device that receives the transmitted signal receives the received signal. Is then temporally separated into a signal representing a single carrier packet and a signal representing a multicarrier packet, and a signal representing a single carrier packet is inverse Fourier transformed.

Example 1

[0019] FIG. 2 shows an overall view of a transmitter according to one embodiment of the present invention. The transmitter is typically provided in a base station and transmits a downlink channel, but may be provided in a mobile station. In this embodiment, the transmitter transmits a W-CDMA packet and an OFCDM packet. More generally, the transmitter transmits a single carrier packet and a multicarrier packet. It is extensible.

[0020] The transmitter includes a first baseband processing unit 201, a second baseband processing unit 202, a multiplexing unit 204, and an RF transmission unit 206. The RF transmitter 206 includes a digital-analog converter 210, a quadrature modulator 212, a local oscillator 214, a bandpass filter 216, a mixer 218, a local oscillator 220, a bandpass filter 222, and a power amplifier 224. Have

[0021] The first baseband processing unit 201, as will be described later, is based on the W-CDMA scheme. A high-band signal processing unit that performs signal processing related to the HSDPA system. For example, necessary parameters are determined by AMC and ARQ. Also, mapping in the Internet Protocol (IP) and signal processing related to the MAC layer and physical layer are performed.

[0022] The second baseband processing unit 202 is a baseband signal processing unit related to the OFCDM system, as will be described later. In this signal processing unit, for example, determination of parameters necessary for AMC and ARQ, mapping in the Internet protocol, signal processing for the MAC layer and the physical layer, and the like are performed.

The multiplexing unit 204 selects and outputs one of the signals output from the first and second baseband processing units 201 and 202, thereby time-multiplexing those signals.

[0024] The RF transmission unit 206 performs processing for transmitting a baseband signal to be transmitted as a radio signal. The digital-analog converter (DZA) converts digital signals into analog signals. The quadrature modulator 210 generates an in-phase component (I) and a quadrature component (Q) having an intermediate frequency from the signal input thereto. The band pass filter 212 removes excess frequency components for the intermediate frequency band. The mixer 218 uses the local oscillator 220 to convert (up-convert) the intermediate frequency signal into a high frequency signal. The bandpass filter 222 removes excess frequency components. The power amplifier 224 amplifies signal power in order to perform radio transmission from the antenna 226.

FIG. 3 shows details of the first and second baseband processing units 201 and 202 according to an embodiment of the present invention. In this example, it is also used for the control channel power OFCDM system for W-CDMA system (the first communication system). The first baseband processing unit 201 includes a convolutional encoder 302, a data modulation unit 304, spreading units 306 and 308, a multiplexing unit 310, and a band limiting filter 312. The first baseband processing unit 201 includes a turbo encoder 322, a data modulator 324, a spreading unit 326, a multiplexing unit 330, a band limiting filter 332, and a transmission TTI control unit 334. The second baseband processing unit 202 includes a turbo encoder 342, a data modulator 344, an interleaver 345, a serial-parallel conversion unit 347, a spreading unit 349, a fast inverse Fourier transform unit 350, a guard interval It has an insertion unit 3 52 and a transmission TTI control unit 354.

[0026] The convolutional encoder 302 increases the error resilience of data transmitted on the control channel. Is encoded. The data modulator 304 modulates the control channel using, for example, a QPSK modulation method. Any suitable modulation scheme may be adopted, but since the amount of information of the control channel is relatively small, in this embodiment, the QPSK modulation scheme with a small number of modulation multi-values is adopted. The spreading unit 306 performs code spreading by multiplying the control channel by a predetermined spreading code. Similarly, spreading section 308 performs code spreading by multiplying a pilot channel by a predetermined spreading code. Multiplexer 310 multiplexes the spread control channel and the spread pilot channel. Multiplexing may be performed using one or more of time multiplexing, frequency multiplexing, and code multiplexing. The band limiting filter 312 is composed of, for example, a root Nyquist filter, and performs band limiting.

[0027] The turbo encoder 322 of the first baseband processing unit 201 performs code encoding for improving error resilience of data transmitted through the data channel. The data modulator 324 modulates the transmission data with an appropriate modulation method. The modulation scheme may be, for example, QPSK, 16QAM, 64 QAM, or any other suitable modulation scheme. The spreading unit 326 code spreads the data channel. Multiplexer 330 multiplexes the code-spread pilot channel and data channel as necessary. For example, when the transmission channels of the control channel and the data channel are different and the propagation paths of the two are significantly different, a pilot channel for the data channel may be transmitted in addition to the pilot channel for the control channel. The band limiting filter 332 is also configured with a root Nyquist filter force, for example, and performs band limiting. The transmission TTI control unit 334 gives the data channel to the multiplexing unit 204 on the basis of the transmission time interval (TTI: Transmission Time Interval) in the first W-CDMA system. TTI defines the duration of one packet (typically one TTI = the duration of one bucket). Ο The TTI of the first communication system may be 2 ms, for example. Details of the operation of the transmission TTI control unit will be described later.

[0028] Similarly, turbo encoder 342 of the second baseband processing unit improves error tolerance of data transmitted on the data channel of the OFCDM system (referred to as the second communication system). The sign y for The data modulator 344 modulates the transmission data with an appropriate modulation method. The modulation method may be any suitable modulation method such as QPSK, 16QAM, 64QAM, and the like. Interleaver 345 determines the data channel to be transmitted. Change the order of signals to be displayed. The serial-parallel converter (SZP) 347 converts a serial signal sequence (stream) into a plurality of parallel signal sequences. The spreading unit 349 code spreads the data channel. The fast inverse Fourier transform unit 350 performs fast inverse Fourier transform on the input signal and performs OFDM modulation. The guard interval insertion unit 352 creates a symbol in the OFDM scheme by adding a guard interval to the signal to be transmitted. As is well known, the guard interval is obtained by duplicating the beginning or end of the symbol to be transmitted. The transmission / reception control unit 354 provides the data channel to the multiplexing unit 204 based on the transmission time interval (TTI) in the second communication system. As with the first communication system, the TTI defines the duration of one packet (typically one TTI = the duration of one packet). Ο The TTI of the second communication system For example, it may be 0.25 ms. Details of the operation of the transmission TTI control unit will also be described later.

[0029] The control channel input to first baseband processing section 201 is convolutionally encoded, QPSK modulated, code spread, and multiplexed by multiplexing section 310 together with the spread pilot channel. The multiplexed signal is band-limited and provided to the multiplexing unit 204.

[0030] The data channel input to first baseband processing section 201 is encoded by turbo encoder 322, modulated, spread, band-limited, and input to transmission TTI control section 334. The transmission TTI control unit 334 provides a data channel from various users to the multiplexing unit 204 for each packet, or provides a retransmission target packet to the multiplexing unit 204 in order to retransmit a transmitted packet in response to a request.

[0031] The data channel input to second baseband processing section 202 is encoded by turbo encoder 342, modulated, rearranged by interleaver 345, parallelized by serial-parallel conversion section 347, and subcarriers. Diffused for each component. The spread data channel is modulated by the fast inverse Fourier transform unit 350 using the OFDM method, and a guard interval is added to the modulated signal, which is input to the transmission TTI control unit 354. The transmission TTI control unit 354 provides a data channel having various user capabilities to the multiplexing unit 204 for each packet, or supplies a retransmission target packet to the multiplexing unit 204 in order to retransmit the transmitted packet in response to a request. .

[0032] In this way, baseband processing is performed, multiplexed by the multiplexing unit 204, Radio transmission is performed from the antenna 226 via the RF transmission unit 206 in FIG.

First Communication System Power A data channel to be transmitted is a single carrier packet. The data channel on which the second communication system is also transmitted is a multi-carrier packet. Therefore, the frequency spectrum waveforms of the input signal of the transmission TTI control unit 334 and the input signal of the transmission TTI control unit 354 are significantly different (FIG. 4). Therefore, if these signals are transmitted simultaneously in the same frequency band, it is expected that the interference between the systems will become very large.

[0034] By the way, in a W-CDMA 3G communication system (first communication system) such as IMT2000, an automatic repeat request (ARQ) control method is adopted, and a certain packet is transmitted. If necessary, the same packet is retransmitted after a predetermined period. This predetermined period or the time waiting for retransmission (retransmission waiting period) is defined by the standard to be a period of 5TT 1 (5 packets) (in other words, the DSCH round trip time (RTT) is 6ΤΠ). ) ₀ Within this retransmission waiting period, another packet for the same or different user is transmitted. The inventors of the present invention, paying attention to this point, have found that the coexistence of both systems can be realized by transmitting not only the packet of the same system but also the packet of another system within the retransmission waiting period.

[0035] FIG. 5 shows a conceptual diagram of a packet transmitted by the transmitter of FIGS. FIG. 5 shows a packet related to the control channel and a packet for the data channel used in the first and second communication systems. In the figure, the horizontal direction (left-right direction) represents the time direction. As described above, the control channel is shared by both the first and second communication systems and is transmitted continuously in time. Packets related to the data channel are time-multiplexed and transmitted between the first and second communication systems. In the example shown in the figure, a state in which a packet (single carrier packet) of the first communication system and a packet (multicarrier packet) of the second communication system are alternately transmitted is shown. In the figure, single carrier packets are transmitted in the time slots indicated by Al, A2,..., And multicarrier packets are transmitted in the time slots indicated by Bl, B2,. In this embodiment, the TTI of a single carrier packet is 2 ms, and the TTI of a multicarrier packet is 0.25 ms. As shown in the enlarged view, each time slot B (i = l, 2, ...;) for multicarrier packets Contains eight time slots B, B, ..., B. Therefore, single carrier par il i2 i8

After transmitting one packet, eight multi-carrier packets are transmitted, then a single carrier packet is transmitted again, and then the transmission TT I control units 334 and 336 and the multiplexing unit are transmitted in the same manner. 204 works. The specific value of the transmission time interval TTI for each communication system is just an example, and various other values may be adopted.

[0036] When such signal transmission is performed, the first communication system can satisfactorily receive the control channel and the data channel. However, due to this control channel, the data channel of the second communication system is subject to some intersystem interference. However, because the amount of information in the control channel is small, such interference will be negligible in many cases.

[0037] Regarding retransmission of a packet, as shown in the figure, a single carrier packet is retransmitted in the same single carrier packet after 5 TTIs have elapsed since the transmission. For example, a single carrier packet transmitted in time slot A1 is retransmitted in time slot A4. Therefore, the existing specifications regarding the first communication system need not be changed. The multi-carrier packet is also retransmitted after 5 days (after the second communication system). In this case, as shown in the enlarged view of FIG. 5, the packet transmitted in B in time slot B2 immediately after time slot A2 is retransmitted in time slot B. Similarly, times

21 27

Packets sent in lot B are retransmitted in time slot B. However, Thailand

22 28

The packet sent in time slot B is sent to B in time slot B3 immediately after time slot A3.

twenty three

Will be resent at Similarly, packets sent in time slots B, B, B, B, B

31 24 25 26 27 28

Are also retransmitted in time slots B, B, B, B, B after time slot A3. Follow

32 33 34 35 36

Packets sent in time slots B and B are retransmitted without delay, but

21 22

Retransmission of packets transmitted in the base stations B to B is delayed by about 2 ms (8 packets).

23 28

However, it should be noted that this delay can achieve a system overlay (overlay) by allowing this delay to be much shorter than the retransmission bandwidth period of the first communication system (5 TTI = 10 ms). Cost.

[0038] In FIG. 5, packets of the first and second communication systems are alternately transmitted every 2 ms. However, the present invention is not limited to such an embodiment. FIG. 6 is a diagram showing another aspect of the transmission method. In FIG. 6, the packets of the first and second communication systems are transmitted alternately every 6 ms. That is, after three single carrier packets are transmitted over time slots Al, A2, A3, 8 x 3 = 24 multicarrier packets are transmitted over time slots Bl, B2, B3, and so on. Is done. In addition to the illustration, any suitable transmission method may be used. More generally, one or more single carrier packets and one or more multicarrier packets may be transmitted during the retransmission waiting period for single carrier packets.

Example 2

FIG. 7 shows the first and second baseband processing units 201 and 202 according to an embodiment of the present invention. Elements already described with respect to Figure 3 are given similar reference numerals and redundant description is omitted. In this embodiment, a control channel is prepared separately for each of the first and second communication systems, and these are transmitted while being time-multiplexed with the data channel. Note that the multiplexing units 310 and 330 in FIG. 3 are depicted integrally as the multiplexing unit 310 in FIG. Therefore, in FIG. 7, the convolutional encoder 362, the data modulator 364, the interleaver 365, the serial / parallel converter 367, the spreading unit 369, and the multiplexing unit 348 are related to the second control channel. Is drawn. Since these elements are the same as those already described, redundant description is omitted.

FIG. 8 shows a conceptual diagram of a packet transmitted from the transmitter according to the present embodiment. As shown in the figure, the data channel is transmitted alternately between the first and second communication systems, as in FIG. In this embodiment, the control channel is also transmitted alternately according to the switching. That is, the single carrier packet and the control channel are multiplexed by the multiplexing unit 310, and transmission is started simultaneously and transmission is stopped simultaneously. Similarly, the multicarrier packet and the control channel are multiplexed by the multiplexing unit 348, and transmission is started simultaneously and transmission is stopped simultaneously. By adopting such a transmission method, inter-system interference caused by the control channel can be suppressed.

Example 3

FIG. 9 shows details of a baseband processing unit according to an embodiment of the present invention. Regarding Figure 3 Elements that have already been described are given similar reference numbers, and redundant descriptions are omitted. It should be noted that in Fig. 9, the elements related to the control channel are not drawn for simplicity. In FIG. 9, an interleaver 902, a fast Fourier transform unit 904, and a band limiting filter 906 are depicted on the first baseband processing unit 201 side.

[0042] Interleaver 902 changes the arrangement of data channel signals according to a predetermined pattern.

[0043] The fast Fourier transform unit 904 performs fast Fourier transform on the spread data channel.

As a result, the time domain input signal is converted into a frequency domain signal and output.

[0044] The band limiting filter 906 performs band limiting in the same manner as the band limiting filters 312 and 332 of FIGS. 3 and 7, but the band limiting filter 906 performs band limiting in the frequency domain. This is different from the band limiting filter 312 and the like shown in FIG.

In the present embodiment, the processing power relating to the multiplexing unit 204, the fast inverse Fourier transform unit 350, and the guard-inner insertion unit 352 is performed in common to the first and second baseband processing units 201 and 202. Therefore, it should be noted that the transmission TTI control units 334 and 354 are drawn on the input side. In this embodiment, the processing power after the multiplexing unit 204 is performed in common to the first and second baseband processing units 201 and 202, and a fast Fourier transform unit 904 is provided between the spreading unit 326 and the band limiting filter 906. ing. In the present embodiment, the multi-carrier packet is the same as that already described, and therefore a redundant description is omitted. The single carrier packet is processed by the fast Fourier transform unit 904 and the fast inverse Fourier transform unit 350, so that modulation by the OFDM method is not performed. In this way, a part of signal processing is shared, and the band limiting process of the single carrier packet is performed in the frequency domain by the band limiting filter 906. Special attention should be paid to the fact that the calculation load of the band limiting filter 906 is much lighter than that of the band limiting filter 312 in FIG. In the bandwidth limitation processing in the time domain, in order to obtain the value after bandwidth limitation at each time point, it is necessary to weight and add a plurality of samples before and after that time point. On the other hand, in band-limiting processing in the frequency domain, the value after band limitation at each frequency can be obtained immediately by multiplying one sample of one frequency to be processed by one weighting factor. . FIG. 10 shows a transmitter in which elements are further shared as compared with the baseband processing unit shown in FIG. Duplicate explanations for already described elements are omitted. In FIG. 10, a buffer 1002 and a separation unit 1004 are newly drawn.

[0047] Buffer 1002 receives and temporarily stores data channels for single carrier packets and multicarrier packets. These are selectively input to the turbo encoder in accordance with each transmission time interval TTI.

[0048] Separating section 1004 time-divides the data channel related to the single carrier packet and the data channel related to the multi-carrier packet in accordance with each time.

[0049] Significant sharing of the processing elements as shown in the figure can be realized mainly based on the time-multiplexed output signal power from the first and second baseband processing units 201 and 202. Yes. That is, there are many processing elements that do not require simultaneous processing.

Example 4

[0050] FIG. 11 shows an overall view of a receiver according to an embodiment of the present invention. Such a receiver may be provided in a power base station typically provided in a mobile station. The receiver according to the present embodiment receives signals transmitted from the transmitters of FIGS. In this embodiment, this receiver is provided in a mobile station, and antenna diversity using two antennas is performed in order to improve signal quality. Since signals received for each antenna are similarly processed by similar processing elements, the signal processing elements and functions related to one antenna will be described on behalf of them. The mobile station includes an RF receiving unit 1102 connected to one of the antennas, a first baseband processing unit 1111, and a second baseband processing unit 1112. The RF receiver 1102 includes a low noise amplifier (LNA) 1103, a mixer 1104, a local oscillator 1105, a band pass filter 1106, an automatic gain controller 1107, a quadrature detector 1108, a local oscillator 1109, an analog digital A conversion unit 1110.

[0051] The RF receiver 1002 performs processing such as power amplification, frequency conversion, and band limitation on the high-frequency signal received by the antenna. The low noise amplifier 1103 appropriately amplifies the signal received by the antenna. The amplified signal is converted to an intermediate frequency by the mixer 1104 and the local oscillator 1105 (down-conversion). The band pass filter 1106 removes unnecessary frequency components. The automatic gain controller (AGC) 1107 ensures that the signal level is maintained properly. As such, the gain of the amplifier is controlled. The quadrature detector 1108 uses the local oscillator 1109 to perform quadrature demodulation based on the in-phase component (I) and the quadrature component (Q) of the received signal. The analog-digital converter (AZD) 1110 converts an analog signal into a digital signal.

[0052] The first baseband processing unit 1111 performs baseband processing of signals related to a single carrier communication system (for example, a W-CDMA system) which is the first communication system. In addition, IP connection and protocol processing related to the MAC layer and physical layer are also performed. Baseband processing includes, for example, determining necessary parameters using AMC and ARQ.

[0053] The second baseband processing unit 1112 performs baseband processing of signals related to a multicarrier communication system (for example, OFCDM system) that is the second communication system. In addition, IP connection and protocol processing related to the MAC layer and physical layer are also performed. Baseband processing includes, for example, determining the parameters necessary for AMC and ARQ.

[0054] The mobile station may be a terminal dedicated to the first or second communication system, or may be a terminal that can be shared by both systems. The dedicated terminal includes only one of the first and second baseband processing units. A sharable terminal has both the first and second baseband processing units.

FIG. 12 shows details of the first baseband processing unit 1111 shown in FIG. In FIG. 12, a band limiting filter 1202, a no searcher 1204, a despreading unit 1206, a channel estimation unit 1208, a rake combining unit 1210, a combining unit 1212, and a turbo decoder 1214 are depicted.

[0056] The band limiting filter 1202 is also configured with a root Nyquist filter force, for example, and performs band limiting. The path searcher 1204 searches for a path in the multipath propagation path. The path search is performed, for example, by examining a delay profile. The despreading unit 1206 despreads the signal in accordance with the pass timing. The channel estimation unit 1208 performs channel estimation using path timing. The channel estimator 1208 controls the amplitude and phase so as to compensate for fading generated in the propagation path according to the estimation result. Output control signal. The rake combiner 1210 combines and outputs the despread signal while compensating for each path.

[0057] Combining section 1212 combines received signals obtained for each antenna. Any suitable synthesis method may be employed. The synthesis method may include, for example, a selection method, an equal gain synthesis method, a maximum ratio synthesis method, and the like.

[0058] The turbo decoder 1214 decodes the received signal and demodulates the data.

[0059] A signal received by each antenna is processed for each antenna as described above. The received signal is converted into a digital signal through processing such as amplification, frequency conversion and band limitation in the RF receiver. The digital signal is band-limited for each subcarrier, despread, and rake-combined for each path. A signal for each subcarrier after rake combining is obtained for each antenna, and they are combined and decoded by the combining unit 1212, and the transmitted signal is restored.

FIG. 13 shows details of the second baseband processing unit 1112 of FIG. FIG. 13 shows a symbol timing detection unit 1302, a guard interval removal unit 1304, a fast Fourier transform unit 1306, a demultiplexer or separation unit 1308, a channel estimation unit 1310, a despreading unit 1312, and a parallel-serial conversion. Portion (PZS) 1314, despreading unit 1316, combining units 1318 and 1319, Dintalino 1320, turbo encoder 1322 and Viterbi decoder 1324 are depicted.

The symbol timing detection unit 1302 detects the timing of symbols (symbol boundaries) based on the digital signal!

[0062] The guard inverter removing unit 1304 removes a portion of the received signal power corresponding to the guard interval.

[0063] The fast Fourier transform section 1306 performs fast Fourier transform on the input signal, and performs demodulation of the OFDM scheme. As a result, the received signal is converted into a signal in the frequency domain.

[0064] The demultiplexer 1308 separates the pilot channel, control channel, and data channel multiplexed in the received signal. This separation method is performed corresponding to multiplexing on the transmission side (contents of processing in the multiplexing unit 310 and the like in FIG. 3).

[0065] Channel estimation section 1310 estimates the state of the propagation path using the pilot channel, and A control signal for adjusting the amplitude and the phase is output so as to compensate for the channel fluctuation. This control signal is output for each subcarrier.

[0066] Despreading section 1312 despreads the channel channel after channel compensation for each subcarrier. The code multiplex number is assumed to be C.

mux

[0067] Parallel-serial converter (P / S) 1314 converts a parallel signal sequence into a serial signal sequence.

[0068] Despreading section 1316 despreads the channel compensated control channel for each subcarrier.

The combining units 1318 and 1319 combine the signals processed for each antenna by an appropriate combining method such as a selection method, an equal gain combining method, or a maximum ratio combining method.

[0070] Dinthaler 1320 changes the order in which signals are arranged according to a predetermined pattern. The predetermined pattern corresponds to the reverse pattern of reordering performed by the transmitting interleaver (eg 345 in Fig. 3).

The turbo encoder 1322 and the Viterbi decoder 1324 decode the traffic information data and the control information data, respectively.

[0072] The signal received by the antenna is converted into a digital signal through processing such as amplification, frequency conversion, band limitation, quadrature demodulation, and the like in the RF receiver. The signal from which the guard interval is removed is demodulated by the OFDM method by the fast Fourier transform unit 1306. The demodulated signal is separated into a pilot channel, a control channel, and a data channel by a separation unit 1308. The pilot channel is input to the channel estimation unit, and a control signal that compensates for fluctuations in the transmission path is output for each subcarrier. The data channel is compensated using the control signal, despread for each subcarrier, and converted to a serial signal. The converted signal is rearranged in a dinary bar 1320 by a reverse pattern to the rearrangement performed by the interleaver, and decoded by the turbo decoder 1322. Similarly, in the control channel, channel fluctuation is compensated by the control signal, despread, and decoded by the Viterbi decoder 1324. Thereafter, signal processing using the restored data and the control channel is performed.

Example 5 FIG. 14 shows a baseband processing unit of a receiver according to an embodiment of the present invention. Elements already described in Figs. 12, 13 are given the same reference numbers, and redundant explanations are omitted. The receiver according to the present embodiment receives signals from the transmitter shown in FIGS. Therefore, the signal transmitted from the transmitter and received by the receiver is a signal obtained by time-multiplexing a single carrier packet and a multicarrier packet and then inversely transforming the Fourier transform. In FIG. 14, a demultiplexer 1402, a band limiting filter 1403, a high-speed inverse-field conversion unit 1404, and a dintariba 1406 are newly drawn. Elements related to the control channel are not drawn for the sake of simplicity.

[0074] Similar to the demultiplexer 1308 described in FIG. 13, the demultiplexer 1402 separates the pilot channel, the control channel, and the data channel that are multiplexed into the received signal! /. Further, the demultiplexer 1402 also temporally separates and outputs the single carrier packet that has been time multiplexed.

[0075] The band limiting filter 1403 performs band limiting processing on a signal (time-separated signal) input thereto in the frequency domain. Similar to the band limiting filter 906 in FIG. 9, the band limiting process performed here can be performed very easily.

[0076] Fast inverse Fourier transform section 1404 performs fast Fourier inverse transform on the signal related to the single carrier packet after the band limitation. As a result, the signal related to the single carrier packet is converted into a signal in the time domain.

[0077] The dintariba 1406 changes the order in which the signals are arranged according to a predetermined pattern. The predetermined pattern corresponds to the reverse pattern of reordering performed by the transmitting interleaver (such as 902 in Fig. 9).

A signal received by the antenna is converted into a digital signal through processing such as amplification, frequency conversion, band limitation, orthogonal demodulation, and the like in the RF reception unit. The fast Fourier transform unit 1306 converts the signal from which the guard interval has been removed into a frequency domain signal. For multi-carrier packets, OFDM demodulation is performed. The signal converted into the frequency domain signal is temporally separated into a multicarrier bucket (including pilot channel, control channel, and data channel) and a single carrier packet by a separation unit 1308. Multi-carrier packets are described in Figure 13. Since the same processing is performed, redundant explanation is saved.

[0079] The separated single carrier packet is subjected to band limitation in the frequency domain by the band limiting filter 1202, and then subjected to inverse Fourier transform. By this conversion, the single carrier packet is converted into a time domain signal. The converted signal is despread, channel-compensated, deinterleaved and then decoded.

Example 6

[0080] Embodiments 1 to 5 described above are intended for coexistence of a plurality of systems on the downlink. The sixth embodiment described below typically aims at coexistence of multiple systems in the uplink. In the uplink, apart from high-speed and high-quality channel, there is a strong demand for lower power consumption of mobile stations. In this embodiment, the variable spreading factor chip repetition factor CDMA (VSCRF-CDMA) system power that can be orthogonalized in the frequency domain by the single carrier method is adopted for uplink. The configuration and operation of the transmitter and receiver used for this uplink are almost the same as those of direct sequence CDMA (DS-CDMA) transmitters and receivers. The processing content related to diffusion is greatly different.

[0081] FIG. 15 shows a block diagram of a spreading unit used in a VSCRF—CDMA transmitter. Accordingly, the operation of the spreading unit described below is typically performed at the mobile station. The spreading unit includes a code multiplication unit 1602, an iterative synthesis unit 1604, and a phase shift unit 1606.

[0082] Code multiplication section 1602 multiplies the transmission signal by a spreading code. In FIG. 15, a multiplier 1612 multiplies the transmission signal by a channelization code determined under a given code spreading factor SF. Further, a multiplier 1614 multiplies the transmission signal by a scramble code. The code spreading factor SF in this embodiment is appropriately set according to the communication environment. More specifically, the code spreading factor SF may be set based on one or more of the propagation path state, cell configuration, traffic volume, and radio parameter. The code spreading factor SF may be set by the base station or the mobile station. However, when using information managed on the base station side such as traffic volume, it is preferable to determine the code spreading factor at the base station.

[0083] Iterative combining section 1604 compresses the spread transmission signal in terms of time and repeats it a predetermined number of times (CRF times). The configuration and operation when the number of repetitions CRF is equal to 1 is normal DS—C. It is equal to the case of DMA method (however, when CRF = 1, the phase shift in the phase shift unit is unnecessary). O

[0084] Phase shift section 1606 shifts (shifts) the phase of the transmission signal by a predetermined frequency. The phase amount to be shifted is set uniquely for each mobile station.

[0085] FIG. 16 shows a block diagram of a despreading unit used in a VSCRC-CDMA receiver. This despreading unit typically operates in a base station. The despreading unit includes a phase shift unit 1702, an iterative combining unit 1704, and a code despreading unit 1706.

[0086] Phase shift section 1702 multiplies the received signal by the phase amount set for each mobile station, and separates the received signal into a signal for each mobile station.

[0087] The iterative synthesis unit 1704 expands the repeated data in terms of time (uncompressed).

Restore uncompressed data.

[0088] Code despreading section 1706 performs despreading by multiplying the received signal by the spreading code for each mobile station.

FIG. 17 is a diagram for explaining the main operation in the VSCRF-CDMA system. For convenience of explanation, one data group with a signal sequence after code spreading is represented by d 1, d 2, d 1

1 2 It is expressed by Q, and the period of each data d (i = l, Q) is Τ. One data d is i S i

It may correspond to one symbol or any other appropriate information unit. This group of signal sequences has a period corresponding to T X Q as a whole. This signal

S

A sequence 1802 corresponds to an input signal to the iterative synthesis unit 1604. This signal sequence is compressed to 1ZCRF over time, and the compressed signal is repeated over a period of T X Q.

S

To be converted. The converted signal sequence is represented by 1804 in FIG. Figure 17 also shows the guard interval period. Temporal compression can be performed, for example, using a frequency that is CRF times higher than the clock frequency used for the input signal. As a result, the period of individual data d is compressed to T ZCRF (however, CR i S

Repeated F times). The compressed and repeated signal sequence 1804 is output from the iterative combining unit 1604, input to the phase shifting unit 1606, shifted by a predetermined phase amount, and output. The phase amount is set for each mobile station, and is set so that uplink signals for each mobile station are orthogonal to each other on the frequency axis. Thereby, in the received signal of the uplink or base station The frequency spectrum generally looks like that shown at 1806 in FIG. In the figure, the band indicated as the spreading bandwidth indicates the band that will be occupied if the signal sequence 1802 after spreading is transmitted as it is. The spectrum at the stage of time compression and repetition (the spectrum of the output signal of the repetition synthesis unit 1604) occupies a narrow band, but the band is common to all mobile stations. By shifting the narrow-band spectrum by the phase amount specific to the mobile station, these bands can be prevented from overlapping each other. In other words, by performing time compression, repetition, and phase shift, the frequency band related to each mobile station can be narrowed, and the frequency spectrum related to each mobile station can be arranged in a comb-like shape. Orthogonalization can be realized.

[0090] On the receiving side, an operation opposite to that on the transmitting side is performed. That is, in accordance with the phase amount for each mobile station, the phase is added to the received signal by the phase shifter 1702 in FIG. The input signal is uncompressed in terms of time, converted into a spread signal sequence, and output from the iterative synthesis unit 1704. Despreading is performed by multiplying this signal by a predetermined spreading code by the despreading section 1706. Thereafter, further processing is performed by the elements already described.

[0091] The radio frequency waveform and chip rate of the signal transmitted by the VSCRF-CDMA system employed in the uplink are the same as those of the W-CDMA system. This is because the repeated processing performed in the VSCRF—CDMA system does not change the power chip rate that rearranges the data order. Therefore, for the uplink, the first and second communication systems can be easily coexisted by adopting the VSCRF-CDMA system for the second communication system.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the present invention. For convenience of explanation, the present invention has been described in several embodiments, but one or more embodiments may be used as needed, as the division of each embodiment is not essential to the present invention.

[0093] This international application claims priority based on Japanese Patent Application No. 2005-106913 filed on April 1, 2005, the entire contents of which are incorporated herein by reference.

Claims

The scope of the claims

[1] A transmitter that can be used in a first communication system of a single carrier system and a second communication system of a multicarrier system,

A first retransmission means for transmitting a single carrier packet on a downlink channel and retransmitting the single carrier packet in response to a request after the first retransmission waiting period has elapsed;

A second retransmission means for transmitting a multicarrier packet on a downlink channel and retransmitting the multicarrier packet in response to a request after the second retransmission waiting period has elapsed;

The second retransmission means transmits one or more multi-carrier packets during the first retransmission waiting period.

A transmission device characterized by the above.

[2] Single carrier packet transmission time interval equal to the transmission time interval of multiple multicarrier packets

The transmission device according to claim 1, wherein:

[3] One single carrier packet and multiple multicarrier packets are sent alternately

The transmission device according to claim 2, wherein:

4. The transmission device according to claim 1, wherein the control channel of the first communication system is shared by the first and second communication systems.

[5] The control channel is transmitted continuously in time

The transmitter according to claim 4, wherein:

[6] The first control channel for the first communication system and the second control channel for the second communication system are transmitted separately.

The transmission device according to claim 1, wherein:

[7] The first control channel is transmitted with a single carrier packet, and the second control channel is transmitted with a multicarrier packet

The transmitting device according to claim 6, wherein:

[8] means for Fourier transforming a signal representing a single carrier packet;

Filter means for band limiting the signal after Fourier transform; Means for time-multiplexing the band-limited signal and the signal representing the multi-carrier packet;

Means for inverse Fourier transforming the time multiplexed signal;

The transmission device according to claim 1, further comprising:

[9] It further comprises an encoding means for selecting and encoding one of the signals representing a single carrier or multicarrier packet.

9. The transmission device according to claim 8, wherein

[10] A transmitter that can be used in the first communication system of the single carrier system and the second communication system of the multi-carrier system is

Send a single carrier packet, and after the first retransmission wait period, retransmit the single carrier packet on demand,

Multi-carrier packets are transmitted, and after the second retransmission waiting period, the multi-carrier packets are retransmitted upon request, and one or more multi-carrier packets are transmitted during the first retransmission waiting period. If you want to

A receiving device for receiving the transmitted signal,

Means for Fourier transforming the received signal;

Means for temporally separating the signal after the Fourier transform into a signal representing a single carrier packet and a signal representing a multicarrier packet;

Means for inverse Fourier transforming a signal representing a single carrier packet;

A receiving apparatus comprising: