CN1886958B - Reception device and transmission device - Google Patents

Abstract

A reception device includes: a partial bit demodulation unit (550) for demodulating a partial bit among bits constituting one symbol of each modulation signal by using a detection method different from the likelihood detection; signal point reduction units (514, 516) for reducing the number of candidate signal points by using the partial bit demodulated; and a likelihood detection unit (518) for obtaining reception digital signals (322, 323) by performing most likelihood detection according to the Euclid distance between the reduced number of candidate signal points and the reception point. Thus, it is possible to obtain only some bits which hardly cause an error, by the partial bit demodulation unit (550) and obtain the other bits by the likelihood detection unit (518), thereby effectively improving the error ratio characteristic with a comparatively small circuit size.

Description

Receiving system and dispensing device

Technical field

The present invention relates to and to receive from the modulation signal that many antennas send simultaneously, and carry out the demodulated received device; And the dispensing device that sends modulation signal from many antennas simultaneously.

Background technology

In the past, as the demodulation method that uses many antennas, the technology that discloses as non-patent literature 1 was known to the crowd.Below, with reference to the content that is disclosed in this non-patent literature 1 of accompanying drawing simple declaration.

Among Fig. 1, dispensing device 30 will send the digital signal 1 of signal A and the digital signal 2 that sends signal B, input to modulation signal generation unit 3.Modulation signal generation unit 3 applies BPSK (BinariphasePhase Shift Keying by the digital signal 2 for digital signal 1 that sends signal A and transmission signal B, binary phase shift keying) or QPSK (Quadrature Phase Shift Keying, Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation, quadrature amplitude modulation) modulation such as, obtain to send the baseband signal 4 of signal A and the baseband signal 5 that sends signal B, and these signals are sent to radio-cell 6.

Radio-cell 6 is by the baseband signal 5 for baseband signal 4 that sends signal A and transmission signal B, apply predetermined wireless processing such as frequency inverted and amplification, obtain to send the modulation signal 7 of signal A and the modulation signal 8 that sends signal B, and these signals are supplied with antenna 9 and antenna 10 respectively.In view of the above, the modulation signal 7 that sends signal A is launched as electric wave from antenna 9; And the modulation signal 8 that sends signal B is launched as electric wave from antenna 10.

Receiving system 40 is by carrying out wireless processing such as frequency inverted or amplification by radio-cell 13 for the received signal 12 that is received by antenna 11, and obtains baseband signal 14, and it is issued to Maximum Likelihood Detection unit 19.In the same manner, obtain baseband signal 18 by carrying out wireless processing such as frequency inverted or amplification for the received signal 16 that receives by antenna 15, and it is issued to Maximum Likelihood Detection unit 19 by radio-cell 17.

Maximum Likelihood Detection unit 19 is by detection baseband signal 14,18, and the receiving digital signals 21 that obtains to send the receiving digital signals 20 of signal A and send signal B.At this moment, Maximum Likelihood Detection unit 19 carries out Maximum Likelihood Detection (MLD:MaximumLikelihood Detection) as represented in the non-patent literature 1.

[non-patent literature 1] international Institute of Electrical and Electric Engineers wireless telecommunications and networking meeting 1999,1038 pages, September number, 1999 (IEEE WCNC 1999, pp.1038-1042, Sep.1999.)

Summary of the invention

Problem to be solved by this invention

, for example in the structure of Fig. 1, carried out under the situation of 16QAM at modulation signal generation unit 3,19 when carrying out MLD in the Maximum Likelihood Detection unit, must obtain the Euclidean distance between 16 * 16=256 backup signal location and received signal.And, carried out under the situation of 64QAM at modulation signal generation unit 3,19 when carrying out MLD in the Maximum Likelihood Detection unit, must obtain Euclid (Euclidian) distance between 64 * 64=4096 backup signal location and received signal.If detect to carry out such computing, then the quality of reception (bit error rate characteristic) improves really, but exists because operation times becomes very many, causes circuit scale to become big problem.This problem as mentioned above, order of modulation is remarkable more more at most.

The object of the present invention is to provide a kind of receiving system, can to from a plurality of modulation signals of many antenna transmission with less circuit scale, bit error rate characteristic demodulation preferably.And, the present invention also aims to provide a kind of dispensing device, the transmission signal of its formation can make the recipient can obtain the received signal of better bit error rate characteristic with less circuit scale.

The technical scheme that is used to deal with problems

Receiving system of the present invention adopts following structure, that is, comprising: a plurality of reception antennas are used to receive a plurality of signals that send the dispensing device transmission of a plurality of different modulated signals from a plurality of transmitting antennas respectively; The channel fluctuation estimation unit is used for obtaining channel estimation value between above-mentioned a plurality of transmitting antenna and the above-mentioned a plurality of reception antenna from a plurality of received signals; Separative element is used to use above-mentioned channel estimation value, estimates at least one estimation baseband signal of above-mentioned a plurality of different modulated signals from above-mentioned a plurality of received signals; The partial bit determining unit, be used for determining above-mentioned at least one estimate at least one predetermined bit of baseband signal, this predetermined bit is used to reduce the signaling point as the candidate of decoding; Signaling point reduces the unit, is used to use above-mentioned channel estimation value and at least one bit of having been determined by above-mentioned partial bit determining unit and the combination of the backup signal location having determined to reduce; And the likelihood determining unit, be used for the combination of the above-mentioned backup signal location that reduced by use and above-mentioned a plurality of received signal and carry out maximum likelihood and determine, come above-mentioned a plurality of received signals are decoded.

According to this structure, because at the partial bit demodulating unit, uses the detection method different with likelihood detection, so a part of bit of demodulation only is can be with less operand acquisition partial bit.In addition, in the likelihood detection unit, owing to use the backup signal location reduced to carry out likelihood detection, so can try to achieve remaining bit with less operand, degree of precision.So, partly carry out likelihood detection owing to be made as, can realize that one side reduces the operation times of asking Euclidean distance, one side obtains the receiving digital signals of better bit error rate characteristic.

And, dispensing device of the present invention is the dispensing device from the mutually different modulation signal of many antenna transmission, this dispensing device adopts following structure, promptly, comprise: modulating unit is used for being divided by a plurality of signaling point combinations by using on the IQ plane, and the minimum signal dot spacing in the signaling point combination carries out the signaling point mapping and obtain modulation signal sending bit from the signaling point configuration less than the minimum signal point distance between the signaling point combination; And antenna, be used to send the modulation signal that obtains by modulating unit.

According to this structure, can determine for the shared bit of the signaling point in the signal combination easily and exactly the recipient.Therefore, can form for needs only the receiving system of a part of bit (partial bit) of demodulation modulation signal send signal very easily.

The effect of invention

According to the present invention, can realize a kind of receiving system, this device can carry out demodulation with less circuit scale and bit error rate characteristic preferably to a plurality of modulation signals from many antenna transmission.And, can realize a kind of dispensing device, this device can form the transmission signal, and this transmission signal can make the recipient with less circuit scale, obtains the received signal of bit error rate characteristic preferably.

Description of drawings

Fig. 1 be represent in the past multi-antenna transmission device and the block diagram of receiving system summary structure;

Fig. 2 is the block diagram of the dispensing device structure that relates to of the expression embodiment of the invention 1;

Fig. 3 is the figure of the frame structure of expression embodiment 1;

Fig. 4 is the block diagram of the receiving system structure that relates to of the expression embodiment of the invention 1;

Fig. 5 is the block diagram of the signal processing unit structure of expression receiving system;

Fig. 6 is the figure of the transmission/reception antennas relation of expression embodiment;

Fig. 7 is the bit configuration (Fig. 7 A) of the expression 16QAM that is applicable to modulation signal A and is applicable to the figure of the bit configuration (Fig. 7 B) of the 16QAM of modulation signal B;

Fig. 8 is the figure of the signaling point configuration example of the estimated signal point (backup signal location) of expression when having received the modulation signal B of the modulation signal A of 16QAM and 16QAM;

Fig. 9 is that the bit configuration (Fig. 9 A) of expression 16QAM reaches in the figure of the definite region partitioning method (Fig. 9 B) of the partial bit that is used for 16QAM of embodiment 1;

Figure 10 is the figure of the signaling point state after the signaling point that is illustrated in embodiment 1 reduces;

Figure 11 is the bit configuration (Figure 11 A) of expression 16QAM and is used for the figure that partial bit is determined the region partitioning method of 2 bits of 16QAM (Figure 11 B);

Figure 12 is the block diagram of the dispensing device structure of expression embodiment 1;

The figure of the frame structure (Figure 13 B) of the frame structure (Figure 13 A) of Figure 13 modulation signal A that to be expression send from the dispensing device of Figure 12 and the modulation signal B that sends from the dispensing device of Figure 12;

Figure 14 is the block diagram of expression reception from the receiving system structure of the signal of the dispensing device of Figure 12;

The figure of the region partitioning method (Figure 15 B) of Figure 15 when to be expression by the signaling point configuration (Figure 15 A) of the dispensing device of embodiment 2 and by the partial bit of the receiving system of embodiment 2 determine;

Figure 16 is the block diagram of other structure example of the signal processing unit of expression embodiment 2;

Figure 17 is the figure of the signaling point configuration of expression 64QAM;

Figure 18 is the signaling point configuration of the dispensing device of expression embodiment 3, and the figure that is used for the region partitioning method that the partial bit of receiving system determines;

Figure 19 is the signaling point configuration of the dispensing device of expression embodiment 3, and the figure that is used for the region partitioning method that the partial bit of receiving system determines;

Figure 20 is the block diagram of the dispensing device structure of expression embodiment 4;

Figure 21 is the block diagram of the receiving system signal processing unit structure of expression embodiment 4;

Figure 22 is the figure that is used to illustrate by the calculation process of the soft determined value computing unit of Figure 21;

Figure 23 is the block diagram of other structure example of the signal processing unit of expression embodiment 4;

Figure 24 is the block diagram of the coding unit structure of expression embodiment 5;

Figure 25 is set the tone really among the embodiment 5 figure of likelihood detection cellular construction (Figure 25 C) of the partial bit determining unit structure (Figure 25 B) of partial bit of partial bit determining unit structure (Figure 25 A), the system of setting the tone really in embodiment 5 signal B of partial bit of system signal A and embodiment 5 of expression;

Figure 26 is the block diagram of other structure example of the coding unit of expression embodiment 5;

Figure 27 is the block diagram of expression according to the other structure example of the receiving system signal processing unit of embodiment 5;

Figure 28 is expression according to the block diagram of modulating unit structure that is used to carry out grid coding (trellis coding) modulation of embodiment 6;

Figure 29 is that expression is used for the figure that partial bit is determined the region partitioning method of bpsk signal;

Figure 30 is the block diagram of the dispensing device structure of expression embodiment 7;

Figure 31 is the figure of the frame structure of expression embodiment 7;

Figure 32 is the block diagram of the receiving system structure of expression embodiment 7;

Figure 33 is the block diagram of expression according to the signal processing unit structure of the receiving system of embodiment 7;

Figure 34 is the block diagram of expression according to another structure of the signal processing unit of the receiving system of embodiment 7;

Figure 35 is used to illustrate the definite figure that handles of 1 bit that embodiment 8 is provided; And

Figure 36 is the flow chart that 1 bit of expression embodiment 8 is determined processing sequence.

Concrete 1 mode of implementing

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

(embodiment 1)

Fig. 2 represents the structure of present embodiment dispensing device.Dispensing device 100 is input to modulating unit 102 to digital signal 101, and digital signal 109 is input to modulating unit 110.

As input, the modulated digital signal 101 according to frame structure signal 118 sends to spectrum-spreading unit 104 with the baseband signal 103 that obtains in view of the above to modulating unit 102 with digital signal 101, frame structure signal 118.Spectrum-spreading unit 104 multiply by spreading code with baseband signal 103, with the spread spectrum that obtains in view of the above baseband signal 105 send to radio-cell 106.Radio-cell 106 by to spread spectrum baseband signal 105 apply frequency inverted, amplification etc., obtain modulation signal 107.Modulation signal 107 is exported as electric wave from antenna 108.

As input, send the baseband signal 111 that obtains in view of the above to spectrum-spreading unit 112 by the modulated digital signal 109 according to frame structure signal 118 with digital signal 109, frame structure signal 118 for modulating unit 110.Spectrum-spreading unit 112 multiply by spreading code with baseband signal 111, with the spread spectrum that obtains in view of the above baseband signal 113 send to radio-cell 114.Radio-cell 114 by to spread spectrum baseband signal 113 apply frequency inverted, amplification etc., obtain modulation signal 115.Modulation signal 115 is exported as electric wave from antenna 116.

In addition, in the following description, will be called modulation signal A, will be called modulation signal B from the signal that antenna 116 sends from the signal that antenna 108 sends.

Frame structure signal generation unit 117 will be represented the information of frame structure, and for example the frame structure information of Fig. 3 is exported as frame structure signal 118.

Fig. 3 has represented from the frame structure example of the modulation signal of each antenna 108,116 transmission of dispensing device 100.From the modulation signal A of antenna 108 transmissions, from the modulation signal B that antenna 116 sends, have the channel estimation symbols 201,203 and the data symbols 202,204 that are used for channel estimating.Modulation signal A and modulation signal B that dispensing device 100 is incited somebody to action frame structure as shown in Figure 3 sent in the basic identical moment.Moreover the code element 201 and 203 that is used for channel estimating also can be described as pilot frequency code element, unique character code, lead code.

Fig. 4 represents the receiving system structure of present embodiment.Receiving system 300 is with two antennas, 301,311 received signals.

The received signal 302 that radio-cell 303 will be received by antenna 301, as input, to received signal 302, apply frequency inverted, quadrature demodulation etc., the baseband signal 304 that obtains is in view of the above passed out to despread unit 305.Despread unit 305 is baseband signal 304 despreadings, the baseband signal 306 after the despreading that output obtains in view of the above.

The channel fluctuation estimation unit 307 of modulation signal A with the baseband signal after the despreading 306 as the input, use the frame structure for example press Fig. 3 modulation signal A channel estimation symbols 201 and estimate channel fluctuation, the channel fluctuation signal 308 of the modulation signal A of acquisition is in view of the above sent to signal processing unit 321.In the same manner, the channel fluctuation estimation unit 309 of modulation signal B with the baseband signal after the despreading 306 as the input, use the frame structure for example press Fig. 3 modulation signal B channel estimation symbols 203 and estimate channel fluctuation, the channel fluctuation signal 310 of the modulation signal B of acquisition is in view of the above sent to signal processing unit 321.

Radio-cell 313 will be imported in received signal 312 conducts that antenna 311 receives, and 312 apply frequency inverted, quadrature demodulation etc. to received signal, and the baseband signal 314 that obtains is in view of the above sent to despread unit 315.Despread unit 315 is baseband signal 314 despreadings, the baseband signal 316 after the despreading that output has obtained in view of the above.

The channel fluctuation estimation unit 317 of modulation signal A with the baseband signal after the despreading 316 as the input, use the frame structure for example press Fig. 3 modulation signal A channel estimation symbols 201 and estimate channel fluctuation, the channel fluctuation signal 318 of the modulation signal A of acquisition is in view of the above sent to signal processing unit 321.In the same manner, the channel fluctuation estimation unit 319 of modulation signal B with the baseband signal after the despreading 316 as the input, use the frame structure for example press Fig. 3 modulation signal B channel estimation symbols 203 and estimate channel fluctuation, the channel fluctuation signal 320 of the modulation signal B of acquisition is in view of the above sent to signal processing unit 321.

Signal processing unit 321 with the channel fluctuation signal 310 and 320 of the channel fluctuation signal 308 and 318 of the baseband signal after the despreading 306 and 316, modulation signal A, modulation signal B as input, by using these signals to carry out the detection, decoding etc. of modulation signal A and B, obtain the digital signal 322 of modulation signal A, the digital signal 323 of modulation signal B.Fig. 5 represents the detailed structure of signal processing unit 321, and its detail operations is narrated in the back.

Fig. 6 has represented the relation between the present embodiment transceiver.The signal that will send from the antenna 108 of dispensing device 100 is made as Txa (t), to be made as Txb (t) from the signal that antenna 116 sends, the signal that will receive at the reception antenna 301 of receiving system 300 is made as Rx1 (T), to be made as Rx2 (T) at the signal that reception antenna 311 receives, with the fluctuation of the transmission between each antenna, be made as h11 (t), h12 (t), h21 (t), h22 (t) respectively.So the relational expression of following formula is set up.Wherein, t is made as the time.

[formula 1]

$\left(\begin{array}{c}\mathrm{Rx}1\left(t\right)\\ \mathrm{Rx}2\left(t\right)\end{array}\right)=\left(\begin{array}{cc}h11\left(t\right)& h21\left(t\right)\\ h12\left(t\right)& h22\left(t\right)\end{array}\right)\left(\begin{array}{c}\mathrm{Txa}\left(t\right)\\ \mathrm{Txb}\left(t\right)\end{array}\right)---\left(1\right)$

Fig. 7 A, Fig. 7 B have represented signaling point configuration and the Bit Allocation in Discrete of modulation signal A when each modulating unit 102,110 has carried out 16QAM (QuadratureAmplitude Modulation, quadrature amplitude modulation) and modulation signal B.Fig. 7 A is signaling point configuration and the Bit Allocation in Discrete of modulation signal A, and Fig. 7 B is signaling point configuration and the Bit Allocation in Discrete of modulation signal B.Modulation signal A, modulation signal B are that 1 code element is distributed 4 bits.In this embodiment, 4 bits that in the explanation 1 code element of modulation signal A distributed are recorded and narrated and are (Sa0, Sa1, Sa2, Sa3), and the 4 bits record that 1 code element of modulation signal B is distributed is (Sb0, Sb1, Sb2, Sb3).Also promptly, (Sa0, Sa1, Sa2, Sa3), (Sb0, Sb1, Sb2, Sb3) obtain 16 kinds of values from (0,0,0,0) to (1,1,1,1) respectively.

As Fig. 7 A, Fig. 7 B, modulation signal A, when modulation signal B is 16QAM, through multiplexing and in the received signal that receives, the signaling point that exists 16 * 16=256 to order.The estimated signal point on the I-Q plane of relevant this signaling point of 256 can obtain from the channel fluctuation signal 308 of the modulation signal A of Fig. 4 and the channel fluctuation signal 310 of modulation signal B.Fig. 8 is an example of this signaling point configuration of expression.

The stain of Fig. 8 is represented 256 estimated signal point.And, the signaling point of baseband signal 306 after the despreading of code element 701 presentation graphs 4.At this moment, in the hope of the signaling point distance of 701 of the signaling points of 256 estimated signal points and the baseband signal after the despreading, search the estimated signal point that becomes lowest distance value, can and detect modulation signal A, modulation signal B decoding.For example, code element 702 is (Sa0, Sa1, Sa2, Sa3, Sb0, Sb1, Sb2, Sb3) estimated signal points for (0,0,0,0,0,0,0,0), under the situation of Fig. 8, because in 256 estimated signal point, acceptance point 701 is minimum to the distance of estimated signal point 702, so, can obtain (0,0,0,0,0,0,0,0) as testing result.

By detecting like this, owing to must ask for signaling point distance between acceptance point and the whole estimated signal point at 256, so there is the circuit scale very large shortcoming that becomes.But, also have the advantage that can obtain the good quality of reception (bit error rate characteristic good data).On the other hand, when the detection method of carrying out with the inverse matrix computing of the relational expression of (1) formula,, the shortcoming of bit error rate characteristic variation is arranged though can reduce circuit scale.

The receiving system 300 of present embodiment constitutes with regard to the feature that is based on the two, can obtain the good reception data of quality (bit error rate characteristic) with less circuit scale.

Fig. 5 is the detailed structure of signal processing unit 321 of receiving system 300 features of expression present embodiment.

Separative element 507 with the channel fluctuation signal 310 of the channel fluctuation signal 308 and 318 of modulation signal A, modulation signal B and 320 and despreading after baseband signal 306 and 316 as input, to carry out the inverse matrix computing of (1) formula, obtain to send the estimated signal of signal Txa (t), Txb (t).Separative element 507 is delivered to partial bit determining unit 509 to the estimation baseband signal 508 of the modulation signal A that obtains like this, and the estimation baseband signal 511 of modulation signal B is delivered to partial bit determining unit 512.

Here, separative element 507 and partial bit determining unit 509,512 constitute and use the only partial bit demodulating unit 550 of a part of bit of demodulation modulation signal A, B of the detection method different with likelihood detection.Here, present embodiment is narrated with the situation of carrying out the inverse matrix computing of (1) formula at separative element 507.But, also can for example carry out the MMSE computing, the received signal that a plurality of modulation signals are mixed in together is separated into each modulation signal A, B, mainly be as long as use the detection method different, and only a part of bit of demodulation modulation signal A, B gets final product with likelihood detection.

Operation to partial bit determining unit 509,512 now is illustrated.Because partial bit determining unit 509 is identical with 512 operations of partial bit determining unit, and the signal difference of only handling, so be illustrated in this operation to the partial bit determining unit 509 of modulation signal A.Fig. 9 A represents the coordinate configuration of 16 signaling points (code element) of 16QAM.Hence one can see that, constitutes 4 bits (Sa0, Sa1, Sa2, Sa3) of 1 code element of modulation signal A, obtains arbitrary value from (0,0,0,0) to (1,1,1,1) according to signal point position.

Partial bit determining unit 509 with the estimation baseband signal 508 of modulation signal A as input, when being present in zone 1 shown in Fig. 9 B, the estimation baseband signal 508 of modulation signal A determines Sa0=1, be present at regional 2 o'clock and determine Sa0=0, be present at regional 3 o'clock and determine Sa2=1, be present at regional 4 o'clock and determine Sa2=0, be present at regional 5 o'clock and determine Sa3=1, with of the partial bit information determined 510 outputs of this information as modulation signal A.Partial bit determining unit 512 as input, is carried out the estimation baseband signal 511 of modulation signal B and above-mentioned identical operations, the partial bit information of determining 513 of output modulation signal B.

Here, the zone of determining 1 bit being defined as reason as Fig. 9 B, is that correct possibility is higher because among Sa0, Sb1, Sa2, the Sa3,1 bit and remaining 3 bits definite as Fig. 9 B are compared.Therefore even determine this 1 bit, during afterwards detection, the possibility that causes the quality of reception to worsen is also less.

Then, the operation to signaling point minimizing unit 514,516 is illustrated.Signaling point reduce unit 514 with the partial bit information of determining 513 of the partial bit information of determining 510 of the channel fluctuation estimated signal 320 of the channel fluctuation estimated signal 318 of modulation signal A, modulation signal B, modulation signal A and modulation signal B as importing.This is in and does not carry out the situation that signaling point reduces, and from the channel fluctuation estimated signal 318 of modulation signal A, the channel fluctuation estimated signal 320 of modulation signal B, as shown in Figure 8, asks for 256 signaling point candidate points.But, in the present embodiment, with the partial bit information of determining 510 of use modulation signal A and the partial bit information of determining 513 of modulation signal B, as described above, definite information (amounting to 2 bits) according to per 1 bit only has 8-2=6 bit (64 signaling points) still undetermined in 8 bits (256 signaling points).

For example, set,, be input to signaling point and reduce unit 514 information of Sb0=0 the partial bit information of determining 513 as modulation signal B with the information of Sa0=1 the partial bit information of determining 510 as modulation signal A.So signaling point reduces unit 514 and leave out the signaling point that does not become Sa0=1 and Sb=0 value in 256 signaling point (Fig. 8).In view of the above, backup signal location can be reduced to 64, signaling point reduces unit 514 information of these 64 signaling points is exported as the signaling point information after will reducing 515.Signaling point reduce unit 516 with the partial bit information of determining 513 of the partial bit information of determining 510 of the channel fluctuation signal 310 of the channel fluctuation signal 308 of modulation signal A, modulation signal B, modulation signal A and modulation signal B as importing, carry out and above-mentioned identical operations, and the signaling point information 517 after the output minimizing.

The signaling point information 515,517 of likelihood detection unit 518 with the baseband signal after the despreading 306,316, after reducing is as importing.Then, signaling point information 515 after reduce and the baseband signal 316 after the despreading obtain the state of Figure 10.In Figure 10, the baseband signal 316 after the despreading is that the signaling point information 515 after the minimizing comprises with stain represents 64 signaling points with the signaling point of code element 701 expressions.Then, the signaling point distance of 701 of the signaling points of the baseband signal after 64 backup signal locations and the despreading is asked in likelihood detection unit 518.That is, ask for branch metric.With its called after branch metric X.In the same manner, likelihood detection unit 518 after reduce signaling point information 517 and the baseband signal 306 after the despreading, ask for the signaling point distance between the signaling point 701 of the baseband signal after 64 backup signal locations and the despreading.Also promptly, ask for branch metric.With its called after branch metric Y.

Then, likelihood detection unit 518 uses branch metric X and branch metric Y, asks for 8 the highest bit sequences of likelihood, and it is exported as the digital signal 322 of modulation signal A and the digital signal 323 of modulation signal B.By the way, in the example of Fig. 5, likelihood detection unit 518 is that the digital signal 322 of modulation signal A and modulation signal B is separated (in parallel) output with 323, but, also can be made as with the digital signal of modulation signal A, modulation signal B together (in series) export as a series of digital signal.

Like this, according to present embodiment, by being provided with: use the detection method different with likelihood detection, and the partial bit demodulating unit 550 of the partial bit in a plurality of bits of 1 code element of definite each modulation signal of formation; The partial bit of use determining and the signaling point that reduces backup signal location reduces unit 514,516; And with based on backup signal location that reduces and the Euclidean distance between the acceptance point, carry out Maximum Likelihood Detection and obtain the likelihood detection unit 518 of receiving digital signals 322,323; Thereby can realize with less circuit scale, effectively promote the receiving system 300 of bit error rate characteristic.Also promptly, owing to 518 use the backup signal location reduced in the likelihood detection unit, so that the operation times of asking for Euclidean distance reduces, so can reduce circuit scale.And for example, because the partial bit of asking for based on the inverse matrix operation result, only be the bit that is difficult to make mistakes, so and whole bits compared based on the situation of inverse matrix operation result likelihood decoding, can suppress deterioration greatly according to the bit error rate characteristic of inverse matrix computing.

(i) other structure example of partial bit determining unit

In the above-described embodiment, be to determine for carry out bit by 509,512 pairs of per 1 bits of partial bit determining unit, reduce at signaling point that the situation that reduces the backup signal location number that amounts to 2 bits respectively in unit 514,516 describes.At this, illustrate by carry out bit by 509,512 pairs of per 2 bits of partial bit determining unit and determine, reduce unit 514,516 at signaling point and reduce the method and the structure of the backup signal location number of 4 bits altogether respectively.

Figure 11 A and Figure 11 B are illustrated in the partial bit determining unit 509,512 of Fig. 8 an example of the definite method when determining 2 bits.Because partial bit determining unit 509 is identical with the operation of partial bit determining unit 512, and the signal difference of only handling, so be illustrated in this operation with regard to the partial bit determining unit 509 of relevant modulation signal A.Figure 11 A represents the coordinate configuration of 16 signaling points (code element) of 16QAM.Hence one can see that, constitutes 4 bits (Sa0, Sa1, Sa2, Sa3) of 1 code element of modulation signal A, according to signal point position, gets the arbitrary value from (0,0,0,0) to (1,1,1,1).

Partial bit determining unit 509 as input, when the estimation baseband signal 508 of modulation signal A is present in the zone 1 that the dotted line with Figure 11 B put under, is determined Sa0=0, Sa2=1 with the estimation baseband signal 508 of modulation signal A; Be present at regional 2 o'clock, determine Sa1=1, Sa2=1; Be present at regional 3 o'clock, determine Sa0=1, Sa2=1; Be present at regional 4 o'clock, determine Sa0=0, Sa3=1; Be present at regional 5 o'clock, determine Sa1=1, Sa3=1; Be present at regional 6 o'clock, determine Sa0=1, Sa3=1; Be present at regional 7 o'clock, determine Sa0=0, Sa2=0; Be present at regional 8 o'clock, determine Sa1=1, Sa2=0; Be present at regional 9 o'clock, determine Sa0=1, Sa2=0.Then, partial bit determining unit 509 with this information determining as modulation signal A 510 outputs of partial bit information.Partial bit determining unit 512, with the estimation baseband signal 511 of modulation signal B as input, carrying out and above-mentioned identical operations, and the partial bit information of having determined 513 of output modulation signal B.

Here, be to compare the zone of determining 2 bits as the reason of determining Figure 11 B because of 2 bits of as Figure 11 B, determining among Sa0, Sb1, Sa2, the Sa3 and remaining 2 bits, correct possibility is higher.Therefore, even determined this 2 bit, after detection in, the possibility that causes the quality of reception to worsen is also lower.

Reduce unit 514 at signaling point, reduce by carrying out carrying out backup signal location with above-mentioned identical operations.At this moment, owing to the partial bit information of determining 510 of modulation signal A is that the partial bit information of determining 513 of 2 bits, modulation signal B is that 2 bits constitute, so become in 8 bits (256 signaling points), only be that 8-4=4 bit (16 signaling points) is undetermined.In view of the above, backup signal location can be reduced to 16.Signaling point information in these 16 becomes the signaling point information after the minimizing.Therefore, owing to, can further reduce the calculating of branch metric, so can further reduce circuit scale in likelihood detection unit 518.But, if the bit numbers of determining in partial bit determining unit 509,512 increase, the then quality of reception deterioration that can become.

(ii) to the application of multi-carrier mode

The configuration example of the situation that applies the present invention to multi-carrier mode is described here.As multi-carrier mode, be that example describes with the situation of having used OFDM (Orthogonal Frequency Division Multiplexing, OFDM) mode.

Figure 12 represents the structure of dispensing device.Dispensing device 1100, to modulating unit 1102 supplied with digital signal 1101, and to modulating unit 1112 supplied with digital signal 1111.

Modulating unit 1102,1112, respectively with digital signal 1101,1111, frame structure signal 1122 as input, the modulated digital signal 1101,1111 according to frame structure signal 1122 is sent the baseband signal 1103,1113 that obtains in view of the above to the parallel converting unit (S/P) 1104,1114 of serial.The parallel converting unit 1104,1114 of serial is carried out baseband signal 1103,1113 the parallel conversion of serial respectively, and the parallel signal 1105,1115 that will obtain is in view of the above sent to contrary Fourier transform unit (idft) 1106,1116.Contrary Fourier transform unit 1106,1116 applies contrary Fourier transform to parallel signal 1105,1115 respectively, and the signal 1107,1117 after the contrary Fourier transform that obtains is in view of the above sent to radio-cell 1108,1118.Radio-cell 1108,1118 by respectively the signal 1107,1117 after the contrary Fourier transform being applied frequency inverted, signal amplification etc., obtains modulation signal 1109,1119.Modulation signal 1109,1119 is exported as electric wave from antenna 1110,1120 respectively.

In view of the above, send modulation signal 1109 (modulation signal A) and modulation signal 1119 (modulation signal B) respectively from each antenna 1110,1120 as ofdm signal.

Here, frame structure signal generation unit 1121 is exported the information of frame structure as frame structure signal 1122.The example of in Figure 13 A, Figure 13 B, having represented frame structure.Figure 13 A, Figure 13 B represent frame structure with the T/F axle.Figure 13 A represents the frame structure of modulation signal A, and Figure 13 B represents the frame structure of modulation signal B.Represent by 5 situations about constituting as an example from carrier wave 1 to carrier wave.The code element that is made as the identical moment sends simultaneously.In addition, with the pilot frequency code element 1201 that oblique line is represented, be the code element that is used to carry out channel estimating the recipient.Be called pilot frequency code element herein, but also can use other addresses such as lead code, get final product so long as can carry out the code element of channel estimating.In addition, the 1202 expression data symbols of representing with blank.

Figure 14 represents the structure of receiving system.Receiving system 1300 is with two antennas, 1301,1311 received signals.

The received signal 1302 that radio-cell 1303 will receive with antenna 1,301 1302 applies frequency inverted etc. to received signal as input, and the baseband signal 1304 of acquisition is in view of the above sent to Fourier transform unit (dft) 1305.Fourier transform unit 1305 carries out Fourier transform with baseband signal 1304, the signal 1306 after the Fourier transform that output obtains in view of the above.

The channel fluctuation estimation unit 1307 of modulation signal A with the signal after the Fourier transform 1306 as the input, use the pilot frequency code element 1201 of the modulation signal A of Figure 13 A, 5 channel fluctuations of asking for modulation signal A respectively from carrier wave 1 to carrier wave, the channel fluctuation ensemble 1308 of output modulation signal A (with from carrier wave 1 to carrier wave 5 separately estimated signal and constitute).In the same manner, the channel fluctuation estimation unit 1309 of modulation signal B with the signal after the Fourier transform 1306 as the input, use the pilot frequency code element 1201 of the modulation signal B of Figure 13 B, 5 channel fluctuations of asking for modulation signal B respectively from carrier wave 1 to carrier wave, the channel fluctuation ensemble (channel fluctuation signal group) 1310 of output modulation signal B (with from carrier wave 1 to carrier wave 5 separately estimated signal and constitute).

In the same manner, radio-cell 1313 will be imported in received signal 1312 conducts that antenna 1311 receives, and 1312 apply frequency inverted etc. to received signal, and the baseband signal 1314 that obtains is in view of the above sent to Fourier transform unit (dft) 1315.Fourier transform unit 1315 carries out Fourier transform with baseband signal 1314, and exports the signal 1316 after the Fourier transform that obtains in view of the above.

The channel fluctuation estimation unit 1317 of modulation signal A with the signal after the Fourier transform 1316 as the input, use the pilot frequency code element 1201 of the modulation signal A of Figure 13 A, 5 channel fluctuations of asking for modulation signal A respectively from carrier wave 1 to carrier wave, the channel fluctuation ensemble 1318 of output modulation signal A (so that 5 separately estimated signal constitute from carrier wave 1 to carrier wave).In the same manner, the channel fluctuation estimation unit 1319 of modulation signal B with the signal after the Fourier transform 1316 as the input, use the pilot frequency code element 1201 of the modulation signal B of Figure 13 B, 5 channel fluctuations of asking for modulation signal B respectively from carrier wave 1 to carrier wave, the channel fluctuation ensemble 1320 of output modulation signal B (with from carrier wave 1 to carrier wave 5 separately estimated signal and constitute).

Signal processing unit 1321 is with the signal after the Fourier transform 1306,1316; The channel fluctuation ensemble 1308,1318 of modulation signal A; And the channel fluctuation ensemble 1310,1320 of modulation signal B is as input, carries out the decoding, detection etc. of modulation signal A and B by using these signals, obtains the digital signal 1322 of modulation signal A, the digital signal 1323 of modulation signal B.

It is just passable that signal processing unit 1321 is made as the structure identical with signal processing unit shown in Figure 5 321.Also promptly, can replace the channel fluctuation signal 308 of the modulation signal A of Fig. 5, and the channel fluctuation of input modulating signal A is estimated group 1308; The channel fluctuation signal 310 that replaces modulation signal B, and the channel fluctuation of input modulating signal B is estimated group 1310; Baseband signal 306 after the replacement despreading, and the signal 1306 after the input Fourier transform; The channel fluctuation signal 318 that replaces modulation signal A, and the channel fluctuation of input modulating signal A is estimated group 1318; The channel fluctuation signal 320 that replaces modulation signal B, and the channel fluctuation of input modulating signal B is estimated group 1320; Baseband signal 316 after the replacement despreading, and the signal 1316 after the input Fourier transform.

For example, separative element 507 is estimated group 501,504 with the channel fluctuation of modulation signal A; The channel fluctuation of modulation signal B is estimated group 502,505; Signal 503,506 after the Fourier transform is as input, according to (1) formula each carrier wave is applied the inverse matrix computing, according to the frame structure of frequency-time shaft of Figure 13 A, Figure 13 B, the estimation baseband signal 508 of output modulation signal A, the estimation baseband signal 511 of modulation signal B.

Then, partial bit determining unit 509,512 is for each carrier wave and the above-mentioned bit of determining section in the same manner.And signaling point reduces unit 514,516 and also reduces for each carrier wave and the above-mentioned signaling point that carries out in the same manner, and likelihood detection unit 518 also carries out likelihood detection for each carrier wave.In view of the above, can obtain the digital signal 1322,1323 of modulation signal A, the B of ofdm signal classification.

Like this, for the multi-carrier mode of OFDM mode etc., also can implement the present invention.

(embodiment 2)

Present embodiment than embodiment 1, is determined the part of 2 bits the division of situation is more oversimplified, and is illustrated for the signaling point collocation method that the quality of reception is improved the bigger I-Q plane of effect.By the way,, mainly modulation signal A is illustrated herein, but also can carries out identical processing modulation signal B.

The summary structure of dispensing device and receiving system is identical with embodiment 1.Difference from Example 1 is: the partial bit determining unit of the structure of the modulating unit of dispensing device, receiving system and signaling point reduce the structure of unit.

Represent example at Figure 15 A according to the signaling point configuration of the dispensing device of present embodiment.In addition, Figure 15 B represents to determine method according to the partial bit of present embodiment receiving system.That is,, carry out the signaling point mapping as Figure 15 A by the modulating unit 102,110 of Fig. 1, the modulating unit 1102,1112 of Figure 12.Also have,, carry out the area dividing determining section bit as Figure 15 B by the partial bit determining unit 509,512 of Fig. 5.

Shown in Figure 15 A, the modulating unit of present embodiment is made as 1 group with 4 signaling points and carries out modulation treatment (mapping), makes that the distance between the signaling point of 4 points in 1 group is less, and group becomes greatly with distance between the group.And for example, the distance between the signaling point of 4 points in modulating unit makes 1 group is identical, and the distance between each group is also identical.The such configuration signal point of modulating unit can be divided into the zone the from the 1st to the 4th quadrant simply.

In view of the above, at recipient's demodulation 2 common bits in simply by 4 groups that constitute of signaling point.Also promptly, because the distance between the signaling point in the group is less, and group is bigger with the distance of signaling point between the group, so, can be easily and determine exactly which group (quadrant) acceptance point is contained in, so can be easily and to carry out the part of 2 bits exactly definite.

Particularly, receiving baseband signal is present at regional 1 o'clock on the I-Q plane shown in Figure 15 B, will be at 42 common bits of signaling point in zone 1, and promptly Sa0=1, Sa2=1 are defined as partial bit.And receiving baseband signal is present at regional 2 o'clock, will be at 42 common bits of signaling point in zone 2, and promptly Sa0=0, Sa2=1 are defined as partial bit.In addition, receiving baseband signal is present at regional 3 o'clock, will be at 42 common bits of signaling point in zone 3, and promptly Sa0=0, Sa2=0 are defined as partial bit.And receiving baseband signal is present at regional 4 o'clock, will be at 42 common bits of signaling point in zone 4, and promptly Sa0=1, Sa2=0 are defined as partial bit.

The partial bit determining unit 509 of Fig. 5 is with the information of these 2 bits of determining, as the partial bit information of determining 510 outputs of modulation signal A.And for example, in bit determining unit 512, also carry out identical processing for modulation signal B.

The signaling point of Fig. 5 reduces the information that unit 514,516 uses 4 bits of determining according to partial bit determining unit 509,512, as having narrated among the embodiment 1,256 backup signal locations is reduced to 16 backup signal locations.

Like this, according to present embodiment, modulating unit 102,110,1102,1112 for dispensing device 100,1100, on the IQ plane, be divided into a plurality of signaling point groups by using, and distance is made as the signaling point configuration less than the minimum signal point distance between the signaling point group between the minimum signal point in the signaling point group, and carry out the signaling point mapping to sending bit, can obtain to carry out easily and exactly the effect of determining of partial bit the recipient.

In addition, the distance between the signaling point of 4 points in making 1 group is identical, and makes the distance between organizing and organizing identical, and this just can make the transmission maximum power that the ratio that sends average power is diminished.In view of the above, require to alleviate, so also just can obtain effect that consumed power is diminished owing to send the linear amplification of the power amplifier of system.This when the modulation system of 64 values that are applied to following explanation too.

Moreover, in embodiment 1 or present embodiment, for the identical situation of the signaling point configuration that makes modulation signal A and modulation signal B in addition explanation, even but under the different situation of the signaling point of modulation signal A and modulation signal B configuration, also can obtain identical effect.

For example, at transmit leg, the signaling point configuration that makes modulation signal A is as Figure 15 A, and the signaling point configuration that makes modulation signal B is as Fig. 9 A.Then the recipient, determine 2 bits by the partial bit determining unit 509 of the modulation signal A of Fig. 5, determine 1 bits by the partial bit determining unit 512 of modulation signal B, so just determined to amount to 3 bits.Then, reduce unit 514,516, use the partial bit information of these 3 bits of determining that 256 backup signal locations are reduced to 32 signaling points at signaling point.

And for example, also can consider only to determine the method for modulation signal A partial bit the recipient.Figure 16 is expressed as the structure of the signal processing unit 321 of realizing the method.By the way, in this embodiment, for determining section bit easily is made as the signaling point of modulation signal A as Figure 15 A and disposes.The partial bit determining unit 509 of Figure 16 is carried out 2 bits of modulation signal A and is partly determined based on definite benchmark of Figure 15 B.Signaling point reduces unit 514,516 and uses 2 bits of determining, 256 backup signal locations are reduced to 64 backup signal locations.Likelihood detection unit 518 carries out likelihood detection by asking for the Euclidean distance between 64 signaling points and receiving baseband signal.

So, because as long as determine the partial bit of a relevant side's modulation signal, just can be with the simplifying the structure of partial bit determining unit, so can correspondingly reduce circuit scale.Such structure is made as when carrying out signaling point configuration that partial bit determines than the modulation signal of its other party is easier at a side modulation signal, and is effective especially.

(embodiment 3)

In the present embodiment, be illustrated for the method for the signaling point configuration of the reality in multistage when modulation that modulation system is made as 64 values and definite method of partial bit.The summary structure of dispensing device and receiving system is removed modulation system outside the multistage modulation of multistage modulation conversion to 64 value of 16 values, and is identical with embodiment 1 or embodiment 2.

Figure 17 has represented the signaling point configuration at the 64QAM on I-Q plane.The receiving system of present embodiment by the partial bit determining unit 509,511 of Fig. 5, determines that respectively the area dividing of 1 bit that fallibility is minimum in 6 bits is determined 1 bit.Reduce the signaling point of 2 bit parts by reducing unit 514,516 from 64 * 64=4096 point backup signal location then, backup signal location is reduced to 1024 points by signaling point.Likelihood detection unit 518 carries out likelihood detection by asking for the Euclidean distance between 1024 each backup signal locations and the acceptance point.

In addition, in receiving system, the area dividing when carrying out being determined by partial bit determining unit 509,511 2 bits when determining the partial bit of 2 bits respectively, can reduce to the backup signal location number 256 points.And for example, when the area dividing of determining 3 bits, when determining the partial bit of 3 bits respectively, then the backup signal location number can be reduced to 64 points.For another example,, determine the partial bit of 4 bits respectively, then the backup signal location number can be reduced to 16 points when the area dividing of determining 4 bits.Like this, because the bit number of determining by partial bit determining unit 509,511 is many more, just can reduce the backup signal location number when carrying out likelihood detection more, so just can reduce operand.But under the many more situations of the bit number of being determined by partial bit determining unit 509,511, the bit error rate characteristic also worsens more, and identical situation during the 16QAM of existence and embodiment 1, i.e. the area dividing complicated more shortcoming that becomes.

So in the present embodiment, as the multistage modulation signal point configuration of preferred 64 values, the such signaling point configuration of Figure 18 is used in suggestion.The configuration of the signaling point of Figure 18, as basic conception, identical with explanation among the embodiment 2.That is, carry out signaling point is divided into a plurality of groups, and the minimum Euclideam distance between group and the group is handled greater than the modulation (mapping) of the minimum Euclideam distance between the signaling point in the group.

Particularly, carry out 16 of signaling points are made as 1 group, the distance between 16 signaling point in 1 group is less, but the modulation treatment (mapping) big apart from change between will organize and organize.And for example, the distance between 16 signaling points in modulating unit makes 1 group is identical, and makes the distance between each group identical.Modulating unit can simply be divided into the zone mode configuration signal point of the from the 1st to the 4th quadrant like this.

In view of the above, the recipient, demodulation becomes 2 common bits in the group with 16 formations of signaling point simply.That is, because distance is less between the signaling point in the group, and the signaling point distance between group is bigger, can be easily and determine exactly which group (quadrant) acceptance point is included in, so can be easily and the part of carrying out 2 bits exactly determine.

In the present embodiment, as other preferred signals points configurations of the 64 multistage modulation that are worth, signaling point configuration is as shown in figure 19 used in suggestion.Figure 19 is suitable for the signaling point configuration of multistage modulation of 64 values that each modulation signal is determined the partial bit of 4 bits.The basic conception of this signaling point configuration and above narration identical carried out signaling point is divided into a plurality of groups, and made the minimum Euclideam distance between group, greater than such modulation (mapping) processing of the minimum Euclideam distance between the signaling point in the group.

Particularly, it is less to carry out distance that 4 of signaling points are made as between 4 signaling points in 1 group, 1 group, and the distance between will organizing becomes big modulation treatment (mapping).So, the zone simply can be divided into the mode configuration signal point in 1～16 zone.

In view of the above, the recipient, demodulation common 4 bits in group simply with 16 formations of signaling point.That is, because distance is less between the signaling point in the group, and the signaling point distance between group is bigger, can be easily and determine exactly acceptance point is included in which group (zone 1～16), so, can be easily and the part of carrying out 4 bits exactly determine.

Like this, according to present embodiment, when different 64 value modulation signals are from many antenna transmission separately, be divided into a plurality of groups by the signaling point that is made as 64 values, and the minimum Euclideam distance between group is handled greater than the such modulation (mapping) of the minimum Euclideam distance between the signaling point in the group, can carry out partial bit easily and exactly the recipient and determine that processing and signaling point reduce processing, so can obtain the received signal of better bit error rate characteristic the recipient with less circuit scale.

Moreover, the method of present embodiment is as having illustrated among the embodiment 2, be not limited to make the identical situation of signaling point configuration of modulation signal A and modulation signal B, even signaling point configuration configuration in a different manner at modulation signal A and modulation signal B, so that under the different situation of the bit number of the partial bit that modulation signal A and modulation signal B determine, also can implement.

(embodiment 4)

In the present embodiment, to being suitable for adding the structure of embodiment 1～3, carry out convolutional encoding or the spy broadcasts (turbo) coding, and the soft determined value computational methods of carrying out the recipient under the situation of soft definite decoding describe at transmit leg.Present embodiment can be applicable to the situation of any signaling point configuration that employing describes in the above-described embodiment basically, herein as an example, is example with the situation of carrying out the signaling point configuration that Figure 15 A represents at transmit leg, is illustrated.

Mark Figure 20 that same-sign is represented at counterpart, the structure of the dispensing device of expression present embodiment with Fig. 2.Dispensing device 1900 sends digital signal 1901 to coding unit 1902 inputs.Coding unit 1902, by applying convolutional encoding to sending digital signal 1901, digital signal 101 after obtaining to encode and the digital signal 109 behind the coding send to modulating unit 102,110 with these.

The general structure of receiving system as shown in Figure 4.In the present embodiment, the signal processing unit 321 of Fig. 4 is constituted as the signal processing unit 2000 of Figure 21.In addition, in Figure 21, marked identical symbol with the corresponding part of Fig. 5.

The signal processing unit 2000 of present embodiment has soft determined value computing unit 2001.Signaling point information 515,517 after soft determined value computing unit 2001 will reduce and the baseband signal after the despreading 503,506 use these signals to obtain soft determined value signal 2002 as input, and it is sent to determining unit 2003.The soft determined value signal 2002 of determining unit 2003 decodings, and obtain digital signal 2004.

Be described in detail the processing of this soft determined value computing unit 2001 and determining unit 2003 with reference to Figure 22.

For example, suppose that the dispensing device 1900 of Figure 20 is with the configuration of the signaling point as Figure 15 A transmission modulation signal.And, suppose that the receiving system 300 of Fig. 4 has received this modulation signal.

So at the signal processing unit 2000 of Figure 21, partial bit determining unit 509 is determined 2 bits of Sa0, the Sa2 of modulation signal A based on the area dividing of the signaling point configuration of Figure 15 B, and it is exported as partial bit information 510.In the same manner, partial bit determining unit 512 is determined 2 bits of Sb0, the Sb2 of modulation signal B based on the area dividing of the signaling point configuration of Figure 15 B, and it is exported as partial bit information 513.

Signaling point reduces the information that unit 514 uses 4 bits of obtaining from partial bit determining unit 509,512, the signaling point of ordering from 16 * 16=256, ask for 16 signaling points, it as the signaling point information 515 after reducing, is sent to soft determined value computing unit 2001.In the same manner, signaling point reduces unit 516 also with 16 signaling point information, as the signaling point information 517 after reducing, sends to soft determined value computing unit 2001.

Herein, as an example, the partial bit of the modulation signal A that will determine in partial bit determining unit 509 is made as Sa0=0, Sa2=0, and the partial bit of the modulation signal B that will determine in partial bit determining unit 512 is made as Sb=0, Sb2=0.

At this moment, signaling point information 515 after soft determined value computing unit 2001 uses reduce and the baseband signal 316 after the despreading are carried out the calculating of Figure 22.

(step ST1)

At first, for example, ask for 16 signaling points of signaling point information 515 after the minimizing and the Euclidean distance between the baseband signal after the despreading square.Herein, with Euclidean distance square with D (Sa0, Sa2, Sb0, Sb2, Sa1, Sa3, Sb1, Sb3) this function representation.So in this example because Sa0=0, Sa2=0, Sb0=0, Sb2=0, so ask for D (0,0,0,0, Sa1, Sa3, Sb1, Sb3) Sa1 in, Sa3, Sb1, Sb3 are 16 values of 0 or 1.

(step ST2)

Then, from D (0,0,0,0, Sa1, Sa3, Sb1 in 16 values Sb3), tries to achieve maximum.The maximum of this moment is made as Dmax.

(step ST3)

At last, with actual try to achieve Euclidean distance square 16 signaling points beyond the value of Euclidean distance square of 240 signaling points, all be made as Dmax.In this example, will arrive the value of D (1,1,1,1,1,1,1,1) from D (0,0,0,1,0,0,0,0), all be made as Dmax.Promptly, since with actual try to achieve Euclidean distance square 16 signaling points beyond the Euclidean distance of 240 signaling points, can regard maximum Dmax as, so the square value of the Euclidean distance of these signaling points is set at Dmax without exception greater than the square value of the Euclidean distance of 16 signaling points.In view of the above, the square value of the Euclidean distance of 16 signaling points is effectively utilized, can easily obtain the square value of 256 Euclidean distance.

Then, soft determined value computing unit 2001 with the value (branch metric) of these 256 Euclidean distances square as soft determined value signal 2002 outputs.

Determining unit 2003 as input, is asked path metric and decoding from branch metric with soft determined value signal 2002, and output digital signal 2004.

So, according to signal processing unit 2000, because by only calculating each backup signal location reduced and the Euclidean distance between the acceptance point, and each signaling point that will be in addition and the Euclidean distance between the acceptance point maximum Dmax that all is decided to be above-mentioned Euclidean distance of trying to achieve, and obtain the soft determined value of whole backup signal locations, so can easily obtain the soft determined value of relevant whole backup signal location.

Mark Figure 23 that same-sign is represented at corresponding position, the another kind of structure of the signal processing unit of expression present embodiment with Figure 21.Signal processing unit 2200 has weight coefficient computing unit 2201.

Weight coefficient computing unit 2201 as input, is asked for the weight coefficient corresponding to the reliability that multiply by branch metric with the channel fluctuation signal 310,320 of the channel fluctuation signal 308,318 of modulation signal A and modulation signal B.Herein, when separative element 507 came separation signal by the computing of for example carrying out (1) formula, the weight coefficient that weighted calculation unit 2201 is asked for corresponding to the separation accuracy of signal got final product.Particularly, weighted calculation unit 2201 was as document " soft definite decoder of the channel matrix characteristic value in the employing mimo system " international Institute of Electrical and Electric Engineers individual radio mobile communication international conference 2003, the 1703-1707 page or leaf, in September, 2003 (" Soft-decision decoder employingeigenvalue of channel matrix in MIMO systems " 2003, pp.1703-1707, Sep.2003.) expression is such in, ask for for example minimum power of the matrix exgenvalue of (1) formula, 2202 outputs get final product as the weight coefficient signal with it.

Signaling point information 515,517 after soft determined value computing unit 2001 will reduce and the baseband signal 306,316 after the despreading and weight coefficient signal 2202 are as input, multiply by weight coefficient by the branch metric of will try to achieve, and obtain soft determined value signal 2002.

So, at signal processing unit 2200,, just can further promote the bit error rate characteristic by branch metric be multiply by weight coefficient.Moreover, in the top explanation, just used the situation of the minimum power of eigenvalue to narrate as weight coefficient, weight coefficient is not limited thereto.

And for example, in the present embodiment, be described with regard to the situation of using convolutional encoding, but be not limited thereto, use special broadcasting under the situation of coding, low-density checksum coding etc., also can similarly implement.And, change interweaving of signal sequence even be provided with, leave out the part of signal and reduce deleting of tediously long degree and suspend the coaching and can wait, also can similarly implement.This point to relevant other embodiment too.

In addition, in the present embodiment, illustrated ask for Euclidean distance square, and ask for the example of soft determined value in view of the above, but be not limited to Euclidean distance square, but the likelihood that also goes for other is a benchmark, asks for the situation of soft determined value.This point to relevant other embodiment too.

(embodiment 5)

In the present embodiment, to as what illustrated in the foregoing description, reduce partial bit the recipient, when reducing the processing of backup signal location, more suitably coding (convolutional encoding, spy broadcast coding) method is illustrated.

Dispensing device summary structure as shown in Figure 20.In this embodiment, as an example, suppose that modulating unit 102,110 has adopted the multistage modulation of 16 values of the signaling point configuration shown in Figure 15 A.Simultaneously, receiving system summary structure as shown in Figure 4.

Figure 24 represents the structure of the coding unit of present embodiment.That is, the coding unit 2300 of Figure 24 uses as the coding unit 1902 of Figure 20.

Coding unit 2300 comprises: (Sa0, Sa2) coding unit 2302, (Sa1, Sa3, Sb1, Sb3) coding unit 2304 and (Sb0, Sb2) coding unit 2306.Each coding unit 2302,2304,2306 supplied with digital signal 1901 carries out the encoding process for specific bit respectively.

That is, (Sa0, Sa2) coding unit 2302 will be contained in bit Sa0, the Sa2 coding of digital signal 1901, export the coded message 2303 of this bit Sa0, Sa2.(Sa1, Sa3, Sb1, Sb3) coding unit 2304 will be contained in bit Sa1, Sa3, Sb1, the Sb3 coding of digital signal 1901, export the coded message 2305 of this bit Sa1, Sa3, Sb1, Sb3.(Sb0, Sb2) coding unit 2306 will be contained in bit Sb0, the Sb2 coding of digital signal 1901, export the coded message 2307 of this Sb0, Sb2.

So, be that unit applies encoding process by being made as with predetermined bit, becoming the recipient to be that unit carries out the error correction decoding processing with this bit.In the present embodiment, being that unit applies encoding process by being made as the bit of determining with partial bit the recipient particularly, can be that unit carries out the error correction decoding processing with the partial bit, so be suitable.

(Sa0, Sa1, Sa2, Sa3) signal generation unit 2308 with the coded message 2305 of the coded message 2303 of Sa0, Sa2 and Sa1, Sa3, Sb1, Sb3 as input, generate the signal of Sa0, Sa1, Sa2, Sa3, and it is exported as the digital signal after encoding 101.

In the same manner, (Sb0, Sb1, Sb2, Sb3) signal generation unit 2310 as input, generates the signal of Sb0, Sb1, Sb2, Sb3 with the coded message 2307 of the coded message 2305 of Sa1, Sa3, Sb1, Sb3 and Sb0, Sb2, and with its digital signal 109 outputs after as coding.

Then, the structure to the receiving system that receives such transmission signal describes.The receiving system summary structure of present embodiment as shown in Figure 4.Signal processing unit 321 structures of receiving system 300 as shown in Figure 5.In the present embodiment, the partial bit determining unit 509 of signal processing unit 321 is constituted as Figure 25 A, partial bit determining unit 512 is constituted as Figure 25 B, likelihood detection unit 518 is constituted as Figure 25 C.

Figure 25 A (Sa0, Sa2) decoding unit 2402 as input, obtains decoded bits Sa0, Sa2 to its decoding with the estimation baseband signal 508 of modulation signal A, and with its determining as modulation signal A 510 outputs of partial bit information.

Figure 25 B (Sb0, Sb2) decoding unit 2405 as input, obtains decoded bits Sb0, Sb2 to its decoding with the estimation baseband signal 511 of modulation signal B, and with its partial bit information of determining 513 outputs as modulation signal B.

So, by being that unit carries out error correction coding with the partial bit, can further promote the quality of reception.Also promptly, if since to partial bit determine to exist mistake, then when signaling point reduces, can select wrong signaling point, make to the bit of remainder really the fixed output quota possibility of giving birth to mistake become very high.Corresponding, as present embodiment, be that unit carries out error correction coding with the partial bit, then can improve the possibility that partial bit is correctly decoded, so can reduce the possibility of selecting rub-out signal point when signaling point reduces.

And, more preferably, be made as by (Sa0, Sa2) coding unit 2302 and (Sb0, Sb2) coding unit 2306, carry out than (Sa1, Sa3, Sb1, Sb3) the higher coding of the error correcting capability of coding unit 2305.Like this, just can further improve the possibility of decoded portion bit Sa0, Sa2, Sb0, Sb2 error-free, thereby can further reduce the possibility of the signaling point minimizing that makes mistakes, consequently can further promote the bit error rate characteristic.

And for example, as the signaling point configuration of the multistage modulation of 16 values, compared with 16QAM, the signaling point configuration shown in Figure 15 A, Figure 15 B is more suitable in the realization of the such error correction coding of present embodiment.This is because different according to the zone with respect to the partial bit of determining at 16QAM, and under the situation of Figure 15 A, Figure 15 B, zone whatsoever, partial bit all be fixed as (Sa0, Sa2), (Sb0 Sb2), can realize error correction coding so simply.By the way, in the present embodiment, carry out error correction coding for the multistage modulation of 16 values and be illustrated for example, if but also carry out the error correction coding identical for the multistage modulation of 64 values and handle with present embodiment, also can obtain the effect identical with present embodiment.In this case, also by the reason identical,, can realize error correction coding simply, so also be suitable owing to, adopt as Figure 18, signaling point shown in Figure 19 and dispose compared with 64QAM with above-mentioned explanation.

(the Sa1 of Figure 25 C, Sa3, Sb1, Sb3) signaling point information 515,517 after decoding unit 2411 will reduce and the baseband signal after the despreading 316,306 are as input, with for example Euclidean distance of asking for backup signal location and receiving baseband signal square, try to achieve branch metric, ask path metric and decoding from branch metric then, obtain the receiving digital signals 322 of modulation signal A and the receiving digital signals 323 of modulation signal B.

Like this, according to present embodiment, by on the structure of embodiment 1～4, increase also that to apply with the partial bit be the encoding process of coding unit, also promptly, the transmission bit that is mapped in the same signal point group is encoded in the lump, thus, except that the effect of embodiment 1～4, also can further be lifted at recipient's bit error rate characteristic.

And for example, by apply the encoding process higher than other bit error correcting capability for partial bit, the transmission bit that is about to be mapped in the same signal point group is encoded in the lump, can further be lifted at recipient's bit error rate characteristic.

Moreover, in the present embodiment, to when the coding unit with transmit leg constitutes as shown in Figure 24, the situation that recipient's signal processing unit is constituted as Fig. 5, Figure 25 A, Figure 25 B, Figure 25 C is illustrated, but the structure of coding unit and signal processing unit is not limited only to this.The structure of other of Figure 26 presentation code unit for example, Figure 27 represent signal processing unit other structure for example.

Among the Figure 26 that represents with Figure 24 counterpart mark same-sign, coding unit 2500 comprises: (Sa0, Sa2) coding unit 2302, (Sa1, Sa3) coding unit 2501, (Sb0, Sb2) coding unit 2306 and (Sb1, Sb3) coding unit 2503.Each coding unit 2302,2501,2306,2503 supplied with digital signal 1901 carries out the encoding process for specific bit respectively.

That is, (Sa0, Sa2) coding unit 2302 will be included in bit Sa0, the Sa2 coding of digital signal 1901, export the coded message 2303 of this bit Sa0, Sa2.(Sa1, Sa3) coding unit 2501 will be included in bit Sa1, the Sa3 coding of digital signal 1901, export the coded message 2502 of this bit Sa1, Sa3.(Sb0, Sb2) coding unit 2306 will be included in bit Sb0, the Sb2 coding of digital signal 1901, the coded message 2307 of output Sb0, Sb2.(Sb1, Sb3) coding unit 2503 will be included in bit Sb1, the Sb3 coding of digital signal 1901, export the coded message 2504 of this bit Sb1, Sb3.

(Sa0, Sa1, Sa2, Sa3) signal generation unit 2308 as input, generates the signal of Sa0, Sa1, Sa2, Sa3 with the coded message 2502 of the coded message 2303 of Sa0, Sa2 and Sa1, Sa3, and with its digital signal 101 outputs after as coding.

In the same manner, (Sb0, Sb1, Sb2, Sb3) signal generation unit 2310 as input, generates the signal of Sb0, Sb1, Sb2, Sb3 with the coded message 2307 of the coded message 2504 of Sb1, Sb3 and Sb0, Sb2, and with its digital signal 109 outputs after as coding.

Next, the structure of the signal processing unit 2600 of Figure 27 is described.The signal processing unit 2600 of Figure 27 and the signal processing unit 321 of Fig. 5 are compared, except being provided with the hard decoding unit 2606,2608 of determining, and be provided with soft definite decoding unit 2601,2602 (promptly as partial bit determining unit 509,512, partial bit demodulating unit 2610 comprises separative element 507 and soft definite decoding unit 2601,2602) outside, the structure identical had with the signal processing unit 321 of Fig. 5.

Soft definite decoding unit 2601 with the estimation baseband signal 508 of modulation signal A as input, partial bit Sa0, Sa2 for Figure 26 carry out soft definite decoding, and the information of the partial bit Sa0, the Sa2 that obtain is in view of the above exported as the partial bit information of determining 510 of modulation signal A.In the same manner, soft definite decoding unit 2602 with the estimation baseband signal 511 of modulation signal B as input, partial bit Sb0, Sb2 for Figure 26 carry out soft definite decoding, with the partial bit information of determining 513 outputs as modulation signal B of the information of the partial bit Sb0, the Sb2 that obtain in view of the above.

Signaling point reduces unit 514,516 and uses the partial bit information of determining 510,513, reduces backup signal location, and the signaling point information after reducing 515,516 is sent to likelihood determining unit 2603.

Likelihood determining unit 2603 is with backup signal location and the baseband signal after the despreading 316 after minimizing, and the highest backup signal location of search likelihood carries out likelihood to be determined, obtains bit Sa1, Sa3, Sb1, Sb3.Then, likelihood determining unit 2603 is sent as bit information 2604 bit Sa1, Sa3 to hard definite decoding unit 2606, and bit Sb1, Sb3 are sent to hard definite decoding unit 2608 as bit information 2605.

Determine decoding unit 2606 firmly by hard definite decoded bits information 2604, the bit information 2607 after the error correction of acquisition modulation signal A.In the same manner, determine decoding unit 2608 firmly by hard definite decoded bits information 2605, the bit information 2609 after the error correction of acquisition modulation signal B.

Here, the bit information 2607 after the error correction of the partial bit information of determining 510 of modulation signal A and modulation signal A is equivalent to the bit information of the modulation signal A after the final error correction; Bit information 2609 after the partial bit information of determining 513 of modulation signal B and the error correction of modulation signal B is equivalent to the bit information of the modulation signal B after the final error correction.

So, owing to be provided with soft definite decoding unit 2601,2602 at signal processing unit 2600, ask for the partial bit that is used for the signaling point minimizing by soft definite decoding processing, the situation of for example carrying out determining is firmly compared, can reduce the wrong probability of partial bit, also can improve final bit error rate characteristic.By the way, the signal that is made as after determining for likelihood carries out definite firmly, the reason of doing like this is: owing to determine modulation signal A and modulation signal B simultaneously when carrying out likelihood and determining, determine so be difficult to only carry out the soft of relevant modulation signal A, perhaps only carry out the soft of relevant modulation signal B and determine from principle.

Moreover, in the present embodiment, for the recipient to the bit (Sa1 outside the bit that carries out partial bit and determine, Sa3, Sb1, the situation of Sb3) also encoding is illustrated, and does not encode but also can be made as about the bit that carries out outside the definite bit of partial bit.Be that mainly needing only with the partial bit is that unit encodes, and just can obtain the effect identical with present embodiment.

(embodiment 6)

In the present embodiment, the method in the Trellis-coded modulation of transmit leg execution is proposed.And, be to use the situation of 16QAM mode to be example here as modulation system, be illustrated.

The dispensing device summary constitutes as Fig. 2, sends frame structure such as Fig. 3 of signal.In addition, the receiving system summary constitutes as Fig. 4, detailed formation such as Fig. 5 of the signal processing unit 321 of Fig. 4.

For implementing the Trellis-coded modulation of 16QAM, the modulating unit 102,110 with Fig. 2 dispensing device 100 gets final product as constitute for example shown in Figure 28ly.

In Figure 28,2701,2702,2703 expression shift registers, 2704,2705 expression XOR circuit from input a0, a1, a2, generate b0, b1, b2, b3.Then, baseband signal generation unit 2706 as input, obtains baseband signal 2707 with the mapping of carrying out 16QAM with b0, b1, b2, b3.

Then, the operation with regard to receiving system is illustrated.As described above, the operation of the characteristic of receiving system of the present invention is partial bit determining unit 509,512 (Fig. 5).Because partial bit determining unit 509 and partial bit determining unit 512 are carried out identical operations, so the operation of main declaratives bit determining unit 509 herein.

Partial bit determining unit 509 with the estimation baseband signal 508 of modulation signal A as input, by carrying out for example Veterbi decoding, determine the bit relevant with coding, also be, b0 among Figure 28, b1, b2 are with the partial bit information determined 510 outputs of these information as modulation signal A.In the same manner, the partial bit information of determining 513 (information of 3 bits) of partial bit determining unit 512 output modulation signal B.

Signaling point reduces unit 514,516 and carries out the signaling point minimizing.Then, the information of the b3 of Figure 28 that likelihood detection unit 518 determines the information of the b3 of Figure 28 of sending with modulation signal A, send with modulation signal B, and with it as the digital signal 519 of modulation signal A and digital signal 520 outputs of modulation signal B.

So,, by carrying out Trellis-coded modulation, can easily realize error correction coding, can utilize easy dispensing device structure, effectively be lifted at recipient's bit error rate characteristic at transmit leg according to present embodiment.

(embodiment 7)

In the present embodiment, as number of transmit antennas, reception antenna number example more than two situation, with regard to number of transmit antennas be 3, the reception antenna number is 3, send the modulation signal number is that 3 o'clock concrete structure example is illustrated.

And, in the present embodiment, propose to determine method and signaling point minimizing method for the partial bit that effectively promotes the bit error rate characteristic.

Counterpart with Fig. 2 is being marked Figure 30 that same-sign is represented, the structure of the dispensing device of expression present embodiment.Dispensing device 2900 except that modulation signal A, modulation signal B, has the transmitting element that sends modulation signal C, and in addition dispensing device 100 structures with Fig. 2 are identical.The structure of the transmitting element that sends modulation signal C only is described here.

Modulating unit 2902 as input, is modulated according to frame structure signal 118 digital signal 2901, frame structure signal 118 to digital signal 2901, the baseband signal 2903 that obtains is in view of the above sent to spectrum-spreading unit 2904.Spectrum-spreading unit 2904 multiply by spreading code with baseband signal 2903, with the spread spectrum that obtains in view of the above baseband signal 2905 send to radio-cell 2906.Radio-cell 2906 by to spread spectrum baseband signal 2905 apply frequency inverted, amplification etc., obtain modulation signal 2907 (modulation signal C).Modulation signal 2907 is exported as electric wave from antenna 2908.

Frame structure signal generation unit 117 will be as the information of the frame structure of Figure 31 as 118 outputs of frame structure signal.

Figure 31 represents from the frame structure example of the modulation signal of each antenna 108,116,2908 transmission of dispensing device 2900.From the modulation signal A of antenna 108 transmissions, from the modulation signal B of antenna 116 transmissions, from the modulation signal C that antenna 2908 sends, have the channel estimation symbols 201,203,3001 and the data symbols 202,204,3002 that are used for channel estimating.Dispensing device 2900 sends modulation signal A, modulation signal B, the modulation signal C of frame structure as shown in figure 31 basically simultaneously.And the symbol 201,203,3001 that is used for channel estimating also can be called pilot frequency code element, unique character code, lead code.

Part with Fig. 4 correspondence is being marked Figure 32 that same-sign is represented, the structure of expression present embodiment receiving system.In addition, in the following description, omit about with the explanation of Fig. 4 same operation part.

Herein, the signal that at the dispensing device 2900 of Figure 30, the signal that will be made as Txa (t) from the signal that antenna 108 sends, sends from antenna 116 is made as Txb (t), send from antenna 2908 is made as Txc (t); Receiving system 3100 at Figure 32, the signal that will be made as Rx1 (t) at the signal that antenna 301 receives, receives at antenna 311 is made as Rx2 (t), will be made as Rx3 (t), will fluctuates in the transmission between each transmission/reception antennas at the signal that antenna 3105 receives, be made as h11 (t), h12 (t), h13 (t), h21 (t), h22 (t), h23 (t), h31 (t), h32 (t), h33 (t) respectively, then the relational expression below is set up.Wherein, t is made as the time.

[formula 2]

$\left(\begin{array}{c}\mathrm{Rx}1\left(t\right)\\ \mathrm{Rx}2\left(t\right)\\ \mathrm{Rx}3\left(t\right)\end{array}\right)=\left(\begin{array}{ccc}h11\left(t\right)& h12\left(t\right)& h13\left(t\right)\\ h21\left(t\right)& h22\left(t\right)& h23\left(t\right)\\ h31\left(t\right)& h32\left(t\right)& h33\left(t\right)\end{array}\right)\left(\begin{array}{c}\mathrm{Txa}\left(t\right)\\ \mathrm{Txb}\left(t\right)\\ \mathrm{Txc}\left(t\right)\end{array}\right)---\left(2\right)$

The channel fluctuation estimation unit 3101 of modulation signal C with the baseband signal after the despreading 306 as the input, use the channel estimation symbols 3001 of the modulation signal C of the frame structure of Figure 31 for example to estimate channel fluctuations, the channel fluctuation signal 3102 of the modulation signal C that obtains is in view of the above sent to signal processing unit 3117.In the same manner, the channel fluctuation estimation unit 3103 of modulation signal C with the baseband signal after the despreading 316 as the input, use the channel estimation symbols 3001 of the modulation signal C of the frame structure of Figure 31 for example to estimate channel fluctuations, the channel fluctuation signal 3104 of the modulation signal C that obtains is in view of the above sent to signal processing unit 3117.

In addition, radio-cell 3107 will be imported in received signal 3106 conducts that antenna 3105 receives, and 3106 are affixed by frequency inverted, quadrature demodulation etc. to received signal, and the baseband signal 3108 that obtains is in view of the above sent to despread unit 3109.Despread unit 3109 is baseband signal 3108 despreadings, the baseband signal 3110 after the despreading that output obtains in view of the above.

The channel fluctuation estimation unit 3111 of modulation signal A with the baseband signal after the despreading 3110 as the input, use for example channel estimation symbols 201 of the modulation signal A of the frame structure of Figure 31, estimate channel fluctuation, the channel fluctuation signal 3112 of the modulation signal A that obtains is in view of the above sent to signal processing unit 3117.In the same manner, the channel fluctuation estimation unit 3113 of modulation signal B with the baseband signal after the despreading 3110 as the input, use for example channel estimation symbols 203 of the modulation signal B of the frame structure of Figure 31, estimate channel fluctuation, the channel fluctuation signal 3114 of the modulation signal B that obtains is in view of the above sent to signal processing unit 3117.In the same manner, the channel fluctuation estimation unit 3115 of modulation signal C with the baseband signal after the despreading 3110 as the input, use for example channel estimation symbols 3001 of the modulation signal C of the frame structure in Figure 31, estimate channel fluctuation, the channel fluctuation signal 3116 of the modulation signal C that obtains is in view of the above sent to signal processing unit 3117.

Signal processing unit 3117 with the channel fluctuation signal 3102,3104,3116 of the channel fluctuation signal 310,320,3114 of the channel fluctuation signal 308,318,3112 of the baseband signal after the despreading 306,316,3110, modulation signal A, modulation signal B and modulation signal C as input, by using these signals to carry out the detection, decoding etc. of modulation signal A, B, C, obtain digital signal 322, the digital signal 323 of modulation signal B and the digital signal 3118 of modulation signal C of modulation signal A.

Figure 33 represents a configuration example of signal processing unit 3117.In addition, Figure 34 is the another kind of example of structure of expression signal processing unit 3117.

At first, just the structure of Figure 33 is illustrated.In to the Figure 33 that represents with the part of Fig. 5 correspondence mark same-sign, the separative element 3201 of the partial bit demodulating unit 3230 of signal processing unit 3117, channel fluctuation signal 308 with modulation signal A, 318,3112, the channel fluctuation signal 310 of modulation signal B, 320,3114, the channel fluctuation signal 3102 of modulation signal C, 3104,3116 and despreading after baseband signal 306,316,3110 as input, and for (2) formula, obtain to send signal Txa (t) by carrying out for example inverse matrix computing or MMSE (Minimum Mean Square Error, Minimum Mean Square Error method) computing, Txb (t), the estimated signal of Txc (t).The estimation baseband signal 508 of the modulation signal A that separative element 3201 will obtain is like this sent to partial bit determining unit 509, the estimation baseband signal 511 of modulation signal B is sent to partial bit determining unit 512, the estimation baseband signal 3207 of modulation signal C is sent to partial bit determining unit 3208.Partial bit determining unit 509,512,3208 is sent the partial bit information 510,512,3209 of trying to achieve.

Determining of the partial bit of partial bit determining unit 509,512,3208 is under the situation of 16QAM in for example modulation system, can realize by the method that adopts above-mentioned Fig. 9 B or Figure 11 B.By the way, under the situation of QPSK, can realize with as shown in Figure 29 area dividing by carrying out.Here, modulation system being made as 16QAM, according to as Figure 11 B, is example with the situation of determining 2 bits in 4 bits, is the implementation method of 3 situation with regard to antenna number, is illustrated.

When receiving, then there be 16 * 16 * 16=4096 backup signal location from 3 16QAM signals that different antennas sends simultaneously.Owing to determine 2 bits in partial bit determining unit 509,512,3208 respectively according to modulation signal A, B, C,, reduce to 4096/4/4/4=64 backup signal location by 4096 backup signal locations so reduce unit 514,516,3210 at signaling point.Therefore, in likelihood determining unit 3212, by obtaining the branch metric between the baseband signal after 64 backup signal locations and the despreading, be defined as 1 backup signal location and detect, obtain the receiving digital signals 322,323,3213 of modulation signal A, modulation signal B, modulation signal C.

Like this, be 2 with number of transmit antennas, the reception antenna number is 2, send the modulation signal number be 2 o'clock identical, even be 3 in number of transmit antennas, the reception antenna number is 3, send the modulation signal number is at 3 o'clock, determine by carrying out partial bit, use the partial bit of determining to reduce backup signal location, use the backup signal location that reduces to carry out likelihood and determine, can obtain quality of reception receiving digital signals 322,323,3213 preferably with less operand.

Then, just the structure of Figure 34 is illustrated.Has control unit 3301 at signal processing unit 3117 to Figure 34 of representing with the part of Figure 34 correspondence mark same-sign.

Control unit 3301 with the channel fluctuation signal 3102,3104,3116 of channel fluctuation signal 310,320, the 3114 modulation signal C of the channel fluctuation signal 308,318,3112 of modulation signal A, modulation signal B as input; Estimate the received electric field strength of modulation signal A for example, the received electric field strength of modulation signal B, the electric field strength of modulation signal C.Then, output is not only carried out the control information 3302 that partial bit is determined to the modulation signal of electric field strength minimum.

For example, suppose the received electric field strength minimum of modulation signal A.So the partial bit determining unit 509 of modulation signal A is controlled as does not carry out bit and determines.That is, the bit of Que Dinging is 0 bit.On the other hand, the partial bit determining unit 512 of modulation signal B, the partial bit determining unit 3208 of modulation signal C are controlled as respectively and determine 2 bits.Then, signaling point reduces 0 bit of determining (also being which bit all is not determined) that uses modulation signal A in unit 514,516,3210,2 bits of determining of modulation signal B, 2 bits of determining of modulation signal C, 4096 backup signal locations are reduced to 4096/4/4=256 backup signal location.In likelihood determining unit 3212, by obtaining the branch metric between the baseband signal after 256 backup signal locations and the despreading, be defined as 1 backup signal location and detect, obtain the receiving digital signals 322,323,3213 of modulation signal A, modulation signal B, modulation signal C.

So, by being made as the quality of reception based on each modulation signal, selection is used for the signaling point minimizing with the partial bit of which modulation signal, merely the partial bit of whole modulation signals is used for the situation that signaling point reduces and compares (for example with the such structure of Figure 33 relatively), can obtain the better receiving digital signals of bit error rate characteristic.

Also be, determine that the result reduces backup signal location if merely use the partial bit of whole modulation signals, then the quality of reception is (in the situation of present embodiment, being received electric field strength) partial bit of lower modulation signal determines that result's wrong probability can uprise, the thing followed is that the probability that can't reduce backup signal location exactly also can uprise.Its result might cause the bit error rate characteristic degradation of final receiving digital signals.In the present embodiment, consider this, be made as only use the quality of reception preferably the partial bit of modulation signal determine the result, carry out signaling point and reduce.

Like this, according to present embodiment, by the quality of reception based on each modulation signal is set, being controlled at signaling point reduces in the backup signal location minimizing of unit 514,516,3210, use the control unit 3301 of the partial bit of which modulation signal, can obtain the better receiving digital signals 322,323,3213 of bit error rate characteristic.

Also have, in the present embodiment, to use the situation of received electric field strength to be illustrated as example as the parameter of the quality of reception, but be not limited only to this, for example, also can the finding the inverse matrix computing or the MMSE computing after the carrier power of each modulation signal and the ratio of noise power, with its parameter as each modulation signal quality of reception.

And for example, in the present embodiment, just only the example of two modulation signal decision section bits is illustrated, but iff to a modulation signal decision section bit, the present invention also can similarly implement.

And then, also can make the bit number of determining as partial bit, according to the order of priority of the quality of reception and difference.For example, when the relation of " received electric field strength of the received electric field strength of the received electric field strength of modulation signal A＞modulation signal B＞modulation signal C " is set up, even carry out as determining 2 bits in the partial bit determining unit of modulation signal A, determine 1 bit, determine that in the partial bit determining unit of modulation signal C the partial bit 0 bit determines in the partial bit determining unit of modulation signal B, also can seek good bit error rate characteristic and low computing scale and deposit.

Promptly, the quality of reception based on each modulation signal, be controlled at signaling point that signaling point reduces unit 514,516,3210 when using the partial bit of how many bits in each modulation signal in reducing by control unit 3301, can obtain the better receiving digital signals 322,323,3213 of bit error rate characteristic.

And, in the present embodiment, be illustrated, even but when having used other modulation systems, also can obtain identical effect used the situation of 16QAM as modulation system.

In addition, in the present embodiment, be with number of transmit antennas be 3, the reception antenna number is 3, send the modulation signal number is 3 o'clock example explanation, is that n, reception antenna number are that n, transmission number of signals are the situation of n (n＞2) but also can be widely used in number of transmit antennas.For example, be 2 in number of transmit antennas, the reception antenna number is 2, send the modulation signal number is under 2 the situation, when the received electric field strength of received electric field strength＞modulation signal B of modulation signal A, by determine the partial bit of 2 bits for modulation signal A, carry out the part of 1 bit or 0 bit determines for modulation signal B, and then carry out likelihood and determine, comprise remaining bit and determine to get final product.

And then, in the present embodiment, be to be example explanation with the situation of not encoding, even but when being suitable for error correction coding, use definite method of present embodiment, also can obtain identical effect.

By the way, also can make with the following method: determine the partial bit of modulation signal A, modulation signal B, use this part bit to obtain branch metric BM from the backup signal location that has reduced _ABDetermine the partial bit of modulation signal A, modulation signal C, use the backup signal location of this part bit, obtain branch metric BM from having reduced _ACDetermine the partial bit of modulation signal B, modulation signal C, use this part bit to obtain branch metric BM from the backup signal location that has reduced _BC, by using these branch metrics BM _AB, BM _AC, BM _BCDetermine, obtain the receiving digital signals 322,323,3213 of modulation signal A, modulation signal B, modulation signal C.

And then, carrying out Simulation result can know: the method in the partial bit of the backup signal location minimizing of signaling point minimizing unit is used in the quality of reception control according to each modulation signal that illustrates in the present embodiment, particularly when separative element 3201 (Figure 34) carries out MMSE, can obtain the receiving digital signals 322,323,3213 of extraordinary bit error rate characteristic.

(embodiment 8)

In the foregoing description 1,1 bit when being 16QAM with regard to modulation system determines that partly method (Fig. 9 B) is illustrated.Present embodiment is just partly determined method about 1 bit that can obtain better bit error rate characteristic, is illustrated.

Figure 35 represents that the signaling point of 16QAM disposes and an example of the signaling point of received signal.Among the figure, the signaling point (backup signal location) of from 3401 to 3416 expression 16QAM, the signaling point (acceptance point) of 3417 expression received signals.And Figure 35 also represents simultaneously from the relation of 4 bits of signaling point 3401 to 3416 (S0, S1, S2, S3).

The partial bit of 1 bit of present embodiment is determined in the method, at first, ask for from the Euclidean distance the signaling point 3401 to 3416 of the signaling point 3417 of received signal and 16QAM, obtain the signaling point of the 16QAM that becomes minimum Euclideam distance, and obtain 4 bits of representing by this signaling point.In the example of Figure 35, detect the signaling point of the minimum Euclideam distance between signaling point 3407 conducts and the acceptance point 3417, as the Bit String of 4 bits of representing with this signaling point 3407, obtain (S0, S1, S2, S3)=(1,1,1,1).

Then, for 4 bits (S0, S1, S2, S3), ask for following Euclidean distance respectively.

Owing to tried to achieve " 1 ", be the signaling point of " 0 " so search the value of the S0 position of Bit String (S0, S1, S2, S3) as bit S0.As search result, picked up signal point 3401,3402,3405,3406,3409,3410,3413,3414.Then, ask for the Euclidean distance between these eight signaling points and the acceptance point 3417, and obtain minimum Euclideam distance D _{Min, s0}Value.

In the same manner, owing to tried to achieve " 1 ", be the signaling point of " 0 " so search the value of the S1 position of Bit String (S0, S1, S2, S3) as S1.As search result, picked up signal point 3401,3404,3405,3408,3409,3412,3413,3416.Then, ask for the Euclidean distance between these eight signaling points and the acceptance point 3417, and obtain minimum Euclideam distance D _{Min, s1}Value.

In the same manner, owing to tried to achieve " 1 ", be the signaling point of " 0 " so search the value of the S2 position of Bit String (S0, S1, S2, S3) as S2.As search result, picked up signal point 3409,3410,3411,3412,3413,3414,3415,3416.Then, ask for the Euclidean distance between these eight signaling points and the acceptance point 3417, and obtain minimum Euclideam distance D _{Min, s2}Value.

In the same manner, owing to tried to achieve " 1 ", be the signaling point of " 0 " so search the value of the S3 position of Bit String (S0, S1, S2, S3) as S3.As search result, picked up signal point 3401,3402,3403,3404,3413,3414,3415,3416.Then, ask for the Euclidean distance between these eight signaling points and the acceptance point 3417, and obtain minimum Euclideam distance D _{Min, s3}Value.

Also promptly, search value and be the signaling point of the negative value of the bit Sx that has determined, ask for the Euclidean distance between those signaling points and the acceptance point 3407, and obtain minimum Euclideam distance D _{Min, sx}Value.

Then, search at D _{Min, s0}, D _{Min, s1}, D _{Min, s2}, D _{Min, s3}In obtain maximum person.For example, maximum person is D _{Min, s0}The time, determine S0.That is, maximum person is D _{Min, sy}The time, determine Sy.In view of the above, can in Bit String (S0, S1, S2, S3), select most possible bit.

Sum up above the processing, just become Figure 36.

At first, if begin to handle at step ST0, then the Euclidean distance that detects between the acceptance point 3417 of step ST1 is minimum backup signal location 3407.

In step ST2, make bit in the Bit String (1,1,1,1) that is included in corresponding to backup signal location 3,407 1 bit that once reverses.In step ST3,, search a plurality of backup signal locations that comprise this counter-rotating bit to each counter-rotating bit.In step ST4,, detect the minimum Euclideam distance between a plurality of backup signal locations that acceptance point searches to step ST3 to each counter-rotating bit.In step ST5, detect the Euclidean distance of the maximum in the minimum Euclideam distance of each counter-rotating bit that step ST4 has detected.In step ST6, will be corresponding to the bit of the maximum Euclidean distance that has detected at step ST5, be made as the highest bit of reliability in the Bit String (1,1,1,1) of backup signal location 3407 expressions that step ST1 has detected, it is adopted as partial bit.

That is, from step ST2 to step ST6, the highest bit of reliability in the Bit String of determining to represent by the backup signal location that has detected at step ST1.Then in step ST7 end process.

Like this, according to present embodiment, by detect and the acceptance point of modulation signal between Euclidean distance be minimum backup signal location, counter-rotating is included in corresponding to the bit in the Bit String of the backup signal location that has detected one by one, for each counter-rotating bit, search comprises a plurality of backup signal locations of the bit that reverses, for each counter-rotating bit, detect the minimum Euclideam distance between acceptance point and the above-mentioned a plurality of backup signal locations searched, detect Euclidean distance maximum in the minimum Euclideam distance of the above-mentioned bit that respectively reverses, and will determine as partial bit corresponding to the bit of the maximum Euclidean distance that has detected, can determine low-down 1 bit of wrong probability.

,, carry out herein, then can determine the low-down partial bit of wrong probability (1 bit), so can promote the bit error rate characteristic of the receiving digital signals of final acquisition in partial bit determining unit 509,512 if 1 such bit is determined algorithm.But 1 bit of present embodiment is determined algorithm, is not limited to use the situation of the receiving system of the structure that has illustrated in the foregoing description, and the occasion of the bit of wrong probability minimum in the Bit String that can be widely used in will selecting to represent with signaling point.

Moreover, in the present embodiment, be the example explanation with 16QAM, when other modulation system, also can similarly determine 1 bit.And, ask Euclidean distance can implement similarly with a square replacement of asking for Euclidean distance.

(other embodiment)

Moreover, in the above-described embodiments, mainly be applicable to that with the present invention the situation of spectrum expanding communication mode and OFDM mode is that example is illustrated, but be not limited only to this, for the multi-carrier mode beyond single carrier mode or the OFDM mode and then for also using under the situation of MIMO transmission, also can obtain identical effect with the mode of multi-carrier mode and spectrum expanding communication mode.

In addition, as modulation system, the situation that relates generally to use the multistage modulation of 16 values in addition explanation.But use the situation of the multistage modulation beyond 16 values, also can obtain identical effect.Also promptly, in the above-described embodiments, when having received the multistage modulation signal of 16 values, as Fig. 9 B, Figure 11 B, Figure 15 B represent, tried to achieve partial bit, but be not limited only to this.For example, send with 1 code element under the situation of m value modulation system of m bit, if the k that determines to try to achieve based on the partial bit (bit of k＜m), the m bit is defined as m-k bit (promptly reducing the backup signal location number), and carry out likelihood detection for the backup signal location that has reduced, then can obtain the effect identical with the foregoing description.And the dividing region method when asking for partial bit, be not limited to Fig. 9 B, Figure 11 B, Figure 15 B, Figure 17, Figure 18, Figure 19, also applicable other area dividing.

And for example, in the above-described embodiments, carrying out the situation of inverse matrix computing during mainly with regard to the determining section bit narrates, but definite method of partial bit is not limited to this, mainly is, as long as according to the detection method different with likelihood detection, and operand is less than the detection method of likelihood decoding and asks for partial bit, compared with the situation that whole bits is tried to achieve by likelihood detection, can reduce operand, so can obtain the effect identical with the foregoing description.

And then, in the above-described embodiments, mainly be with number of transmit antennas be 2, the reception antenna number is 2, send number of signals is that 2 situation is the example explanation, the present invention is not limited to this, is that n, reception antenna number are that n, transmission number of signals are the device of n (n 〉=3) applicable to number of transmit antennas also.And for example, also applicable to by make the reception antenna number more than number of transmit antennas, send number of signals, with separate, signaling point synthesize when reducing or select diversity, in the hope of the device of the lifting separation accuracy or the quality of reception.

The present invention is not limited only to the foregoing description, also can carry out all changes and implements.

An aspect of receiving system of the present invention adopts following structure, promptly, this receiving system is the receiving system that receives the modulation signal that the dispensing device that sends different modulated signals respectively from many antennas sent, and comprising: the channel fluctuation estimation unit, ask for the channel estimation value of each modulation signal; The partial bit demodulating unit uses the detection method a part of bit of demodulation modulation signal only be different from likelihood detection; Signaling point reduces the unit, use demodulation partial bit and channel estimation value reduce backup signal location; And the likelihood detection unit, use backup signal location and the receiving baseband signal reduced to carry out likelihood detection.

According to this structure, owing to use the detection method different with likelihood detection at the partial bit demodulating unit, so demodulation part bit only is can be with less operand acquisition partial bit.And, in the likelihood detection unit, owing to use the backup signal location reduced to carry out likelihood detection, so can try to achieve to degree of precision the bit of remainder with less operand.So, carry out likelihood detection, so can reduce the operation times of asking for Euclidean distance on the one hand owing to be made as part; Can obtain bit error rate characteristic receiving digital signals preferably on the other hand.

An aspect of receiving system of the present invention adopts following structure,, also comprises control unit that is, based on the quality of reception of each modulation signal, is controlled at the partial bit which modulation signal backup signal location that signaling point reduces the unit uses in reducing.

According to this structure, carry out the situation that signaling point reduces compared with the partial bit of the whole modulation signals of simple use, can be made as the partial bit that wrong probability is higher is not used in the signaling point minimizing processing, signaling point reduces processing so can carry out more accurately, and can obtain the better receiving digital signals of bit error rate characteristic.

An aspect of receiving system of the present invention adopts following structure,, also comprises control unit that is, based on the quality of reception of each modulation signal, is controlled at the partial bit that signaling point that signaling point reduces the unit uses how many bits in each modulation signal in reducing.

According to this structure, because compared with by merely using the partial bit of same numbers to reduce the situation of signaling point for whole modulation signals, can be made as in the signaling point minimizing is handled and not use the higher partial bit of wrong probability, signaling point reduces processing so can carry out more accurately, and can obtain the better receiving digital signals of bit error rate characteristic.

An aspect of receiving system of the present invention adopts following structure, that is, the partial bit demodulating unit comprises: separative element is used for received signal is separated to each modulation signal; And partial bit determining unit, the Euclidean distance that is used to ask between the acceptance point of the modulation signal that has separated becomes minimum backup signal location, counter-rotating is included in corresponding to the bit in the Bit String of the backup signal location of having tried to achieve one by one, to each counter-rotating bit, search comprises a plurality of backup signal locations of the bit that reverses, to each counter-rotating bit, detect from acceptance point to the minimum Euclideam distance above-mentioned a plurality of backup signal locations, detect maximum Euclidean distance in the minimum Euclideam distance of above-mentioned each counter-rotating bit, will be made as the demodulation part bit corresponding to 1 bit of the maximum Euclidean distance that detects.

According to this structure, owing to can obtain low-down 1 bit of wrong probability by by the partial bit determining unit, signaling point reduces processing so can carry out more accurately, and can obtain the better receiving digital signals of bit error rate characteristic.

An aspect of receiving system of the present invention adopts following structure, that is, the partial bit demodulating unit comprises: separative element is used for the inverse matrix computing by the channel estimate matrix that uses channel estimation value, and each modulation signal is separated; And the partial bit determining unit, the partial bit of the modulation signal of having determined to separate.

An aspect of receiving system of the present invention adopts following structure, that is, the partial bit determining unit comprises: separative element is used for by carrying out MMSE (Minimum Mean Square Error, Minimum Mean Square Error) computing each modulation signal being separated; And the partial bit determining unit, the partial bit of the modulation signal of having determined to separate.

According to these structures,, can come the determining section bit with less operand compared with the situation of carrying out likelihood detection.

Partial bit among the present invention determines that an aspect of method comprises: the minimum range candidate point that the Euclidean distance between the acceptance point of detection modulation signal becomes minimum backup signal location detects step; The bit reversal step of reversing one by one corresponding to the bit in the Bit String of the backup signal location that has detected will be included in; To each counter-rotating bit, the step of searching a plurality of backup signal locations that comprise the bit that reverses; To each counter-rotating bit, detect the step of the minimum Euclideam distance between acceptance point and the above-mentioned a plurality of backup signal locations searched; Detect the step of the maximum Euclidean distance in the minimum Euclideam distance of the above-mentioned bit that respectively reverses; And, will be defined as the step of partial bit corresponding to the bit of the maximum Euclidean distance that has detected.

According to the method, owing to can determine the highest bit of reliability in the Bit String that the backup signal location that has been detected by minimum range candidate point detection step is represented, so can determine low-down 1 bit of wrong probability.

An aspect of dispensing device of the present invention adopts following structure, promptly, this dispensing device is the dispensing device that sends different modulated signals from many antennas respectively, comprise: modulating unit, be used on the IQ plane, being divided into a plurality of signaling point combinations by using, and the minimum signal dot spacing that is made as in the signaling point combination disposes from the signaling point less than the minimum signal point distance between the signaling point combination, and the signaling point that sends bit shines upon and obtains modulation signal; And antenna, be used to send the modulation signal that obtains by above-mentioned modulating unit.

According to this structure, the recipient can be easily and is determined the common bit of signaling point in signal combination exactly.Therefore, can for needs only the receiving system of a part of bit (partial bit) of demodulation modulation signal form and to send signal very easily.

An aspect of dispensing device of the present invention adopts following structure,, also comprises coding unit that is, and the transmission bit that is mapped in the combination of same signal point is encoded together.

According to this structure, owing to being that unit carries out correction process with common partial bit in the signaling point combination, so receiving and to obtain the lower partial bit of wrong possibility with more easy structure the recipient.

An aspect of dispensing device of the present invention adopts following structure, that is, coding unit applies the higher coding of error correcting capability that sends bit than other for the transmission bit that is mapped in the combination of same signal point.

According to this structure,, can obtain the lower partial bit of wrong possibility the recipient.

This specification is according to the Japanese patent application of Japanese patent application 2003-395219 number of on November 26th, 2003 application and application on October 1st, 2004 2004-290441 number.Its content all is contained in this as a reference.

[utilizing on the industry possibility]

Receiving system of the present invention and dispensing device, what can be widely used in MIMO (Multiple-Input Multiple-Output, multiple-input, multiple-output) mode for example or OFDM-MIMO mode sends respectively the wireless communication system of different modulated signals from many antennas.

Claims (6)

1. receiving system comprises:

A plurality of reception antennas are used to receive a plurality of signals that send the dispensing device transmission of a plurality of different modulated signals from a plurality of transmitting antennas respectively;

The channel fluctuation estimation unit is used for obtaining channel estimation value between above-mentioned a plurality of transmitting antenna and the above-mentioned a plurality of reception antenna from a plurality of received signals;

Separative element is used to use above-mentioned channel estimation value, estimates at least one estimation baseband signal of above-mentioned a plurality of different modulated signals from above-mentioned a plurality of received signals;

The partial bit determining unit, be used for determining above-mentioned at least one estimate at least one predetermined bit of baseband signal, this predetermined bit is used to reduce the signaling point as the candidate of decoding;

Signaling point reduces the unit, is used to use above-mentioned channel estimation value and at least one bit of having been determined by above-mentioned partial bit determining unit and the combination of the backup signal location having determined to reduce; And

The likelihood determining unit is used for the combination of the above-mentioned backup signal location that reduced by use and above-mentioned a plurality of received signal and carries out maximum likelihood and determine, comes above-mentioned a plurality of received signals are decoded.

2. receiving system as claimed in claim 1 wherein, also comprises control unit, is used for the quality of reception based on each modulation signal, is controlled at the partial bit which modulation signal backup signal location that above-mentioned signaling point reduces the unit uses in reducing.

3. receiving system as claimed in claim 1 wherein, also comprises control unit, is used for the quality of reception based on each modulation signal, is controlled at the partial bit that signaling point that above-mentioned signaling point reduces the unit uses how many bits in each modulation signal in reducing.

4. receiving system as claimed in claim 1, wherein, Euclidean distance between the acceptance point of the estimation baseband signal that above-mentioned partial bit determining unit is asked for and estimated by above-mentioned separative element is minimum backup signal location, the bit that is included in corresponding in the Bit String of the backup signal location of trying to achieve is reversed one by one, the a plurality of backup signal locations that each counter-rotating bit search comprised the bit that reverses, to each counter-rotating bit, detect the minimum Euclideam distance between above-mentioned acceptance point and the above-mentioned a plurality of backup signal location, detect maximum Euclidean distance in the minimum Euclideam distance of above-mentioned each counter-rotating bit, will be made as partial bit corresponding to 1 bit of the maximum Euclidean distance that has detected.

5. receiving system as claimed in claim 1, wherein, the inverse matrix computing of the channel estimate matrix of above-mentioned separative element by having used above-mentioned channel estimation value, and obtain the estimation baseband signal of each modulation signal.

6. receiving system as claimed in claim 1, wherein, above-mentioned separative element obtains the estimation baseband signal of each modulation signal by carrying out MMSE (Minimum Mean Square Error, Minimum Mean Square Error method) computing.

Images