Abstract: Disclosed is a wireless communication apparatus in which reception precision characteristics are improved, by specially adapting the modulating processing in respect of the code words for each encoding system. A wireless communication apparatus (100) wherein an encoding processing section (120) includes a convolutional encoder that performs convolutional encoding of fixed information blocks made up of K bits. In code word partial sequences obtained on the basis of the head and tail in a fixed information block, a modulating section (130) maps bits, from bit groups constituting single symbols, to bits associated with groups having poor quality characteristics, prioritising systematic bits over parity bits. In this way, the reception quality characteristics in first code word partial sequences having good error characteristics is equalised.

Abstract: A communication apparatus wherein in a case of reporting a reception quality measured for each of a plurality of subbands, even if the band is widened, the degradation in transmission efficiency can be avoided. In this apparatus, an antenna (101) receives the pilot signals superimposed on a plurality of subbands in a predetermined band. A quality level calculating unit (107) uses the received pilot signals to measure the reception qualities of the respective subbands. A CQI selecting unit (109) selects one of a plurality of CQI values that corresponds to one of the measured reception qualities for each subband. A feedback information generating unit (110) calculates a first average value of the selected CQI values, calculates a second average value of the CQI values indicating better reception qualities than the first average value, and calculates a difference value between the second average value and each of the CQI values indicating better reception qualities than the second average value.

Abstract: A wireless communication system capable of achieving adaptive STTD (Space-time Transmit Diversity). In this system, a receiving apparatus uses a channel estimation to calculate SINR (Signal to Interference and Noise Ratio) of each of substreams in all the combinations of transmission antennas and also calculate the performance of the whole system in all the combinations of transmission antennas, thereby deciding a particular combination, which provides the best performance of the whole system, and obtaining a parameter for antenna selection. The SINR of each substream in the decided particular combination is used to decide an AMC parameter. A transmitting apparatus performs STTD and AMC based on the AMC parameter fed back from the receiving apparatus, and further selects, based on the antenna selection parameter fed back from the receiving apparatus, a particular combination of transmission antennas for performing a transmission.

Abstract: Provided is a carrier allocation method in a multi cell OFDMA system capable of improving the system capacity and the bit error rate performance. In the method, a user terminal U which has received broadcast information (S101) uses an empty carrier to transmit a known symbol to a base station device (S103). The base station device estimates an average channel gain of an empty carrier block by using the received known symbol (S104), compares the channel gain sizes of the respective carrier blocks according to the estimated average channel gain and allocates a carrier block having a large channel gain to the user terminal (S105), and compares channel gains of the respective carriers in the carrier block allocated to the user terminal and selects a carrier having a channel gain lower than a predetermined threshold value (S106).

Abstract: A MIMO transmitting apparatus wherein a low power consumption and a high performance can be achieved by taking the influence of variation in communication distance into account. In this apparatus, a low power consumption design part (701) selectively decides, based on the distance from the other end of communication, whether to perform a pre-coding. When deciding to perform the pre-coding, the low power consumption design part (701) instructs a modulating part (702) to perform a low-order QAM modulation, while instructing a pre-coding part (703) to perform a pre-coding. When instructed to perform a low-order QAM modulation, the modulating part (702) uses a low-order QAM modulation scheme to modulate an input information bit sequence. When instructed to perform a pre-coding, the pre-coding part (703) uses a pre-coding matrix to pre-process the input information bit sequence.

Abstract: A wireless communication apparatus in a closed loop communication wherein a channel resource can be shared among users and hence the capacity of the communication system can be increased.

Abstract: A transmission bit and transmission power distributing method that can reduce the arithmetic amount in a multiantenna-input/multiantenna-output (MIMO) wireless communication system. This method comprises steps of calculating a signal-to-interference-noise ratio (SINR) gain after MIMO detection of each of transport substreams (S601, S602); optimizing, based on the acquired SINR gain, a transmission bit and transmission power distribution in the space domain for all transport substreams on a particular subcarrier in the frequency domain, thereby deciding a transmission bit and transmission power distribution parameters (S603, S604); and optimizing a transmission bit and transmission power distribution for adjacent subcarriers, by sequentially using the transmission bit and transmission power distribution parameters distributed on the subcarrier for which the transmission bit and transmission power distribution parameters have been decided (S605 to S610).

Abstract: A multi-antenna communication method capable of improving the retransmission performance in a multi-antenna transmission. In this method, firstly, the reception quality of a substream to be retransmitted is acquired (Step 401). Then, it is determined for the substream whether any transmission antennas, which satisfy a target value related to the foregoing reception quality when they are used for the retransmission, are existent among the transmission antennas that are candidate antennas to be used for there transmission (Step 405). Then, if there exist any transmission antennas satisfying the target value, a transmission antenna to which the poorest channel characteristic corresponds is selected from among those transmission antennas satisfying the target value, and the selected transmission antenna is designated as an antenna to be used for retransmitting the foregoing substream (Step 406).

Abstract: A multiantenna communication system comprises a determining part (116) that calculates correlation values each between the channel characteristics of the resource blocks in an STBC (Space Time Block Code) and determines a combination pattern exhibiting the highest correlation; a connection distributing part (103) that maps, into a time domain, a frequency domain and a spatial domain, the STBC encoded transport data in accordance with the combination pattern determined by the determining part; a plurality of transmission antennas (107) for transmitting respective signals associated therewith; a plurality of reception antennas (108) for receiving the signals transmitted from the transmission antennas; and a connection multiplexing part (113) that extracts the signals, which belong to the same STBC, from the signals mapped into the time domain, frequency domain and spatial domain in accordance with the combination pattern determined by the determining part, and then combines the data blocks.

Abstract: A communication apparatus capable of improving the spectrum usage rate of a system, especially, the spectrum usage rate in connection with both a fast fading and a channel estimation error as compared with the conventional sub-band adaptive method, while reducing the degree of the difficulty in achieving the adaptation, and further reducing the feedback overhead. In this apparatus, a sub-band group AMC parameter selecting part (318) selects an AMC parameter of each sub-band. An adaptive reception control part (503) must control an adaptive demodulating/decoding part (311), while controlling a parallel/serial converter (312) in a stage preceding the adaptive demodulation and decoding processes, and combining received symbols in the same sub-band group for demodulation and decoding.

Abstract: A transmitting apparatus capable of enhancing the certainty of data transmission of MIMO system, improving the system throughput, and providing a retransmission technique adaptive to the multi-antenna transmission. In this apparatus, a serial/parallel converting part (300) serial/parallel converts the data, which is to be transmitted, into a number nT of data substreams. A data rearranging part (301) rearranges, based on feedback information, the nT data substreams. CRC encoding parts (302) CRC encode the respective data substreams. Modulating/encoding parts (303) modulate and encode the respective corresponding data substreams. A number nT of transmission antennas (304) transmit the data substreams.

Abstract: First normalizing means (12) normalizes first and second code streams (s1, s2). First spreading means (13) spreads the output of the first normalizing means (12). STTD coding means (14) subjects the first and second code streams (s1, s2) to STTD coding. Second normalizing means (15) normalizes the output of the STTD coding means (14). Second spreading means (16) spreads the output of the second normalizing means (15) by means of the same spreading code as that of the first normalizing means (12). Orthogonal transforming means (17) gives the negative signs to odd chips in a second path spread sequence of each code and exchanges the orders of the odd and even chips. Combining means (18) adds first and second spread sequences of the second path produced by orthogonally transforming the first and second spread sequences of the first path. With this, by using the orthogonality of the transmitted sequences at the receiving side, the reception signal can be detected with a lower complexity.

Abstract: A wireless communication apparatus in a closed loop communication wherein a channel resource can be shared among users and hence the capacity of the communication system can be increased.

Abstract: There is provided an antenna selection method and others capable of reducing a transmission error ratio and a calculation amount. In this method, a reception side feeds back M-column channel estimation matrix H_e to a transmission side (ST701). Next, the number K of the emission antennas is confirmed. When I=1 (that is, when the first antenna is selected), it is initialized and the emission channel matrix H is initialized by “0” (ST702). Next, it is judged whether I<K (ST703). If the judgment result is “NO”, the antenna selection process is terminated and the channel matrix H is outputted (ST704). If I<K, one column is added to the channel matrix H to constitute H1 and QR decomposition is performed for all the possible (M?I+1) H1 before selecting one H1 from all the H1 (ST705). Next, H=H1 is set and control is returned to ST703 (ST706).

Abstract: An input control apparatus capable of suppressing characteristic deterioration, reducing the circuit scale of a turbo decoder and effectively using memory of the turbo decoder. In this apparatus, control section (110) acquires information on a coding rate and coding block length of a received signal, determines the number of bits of systematic part Y1, and parity parts Y2 and Y3 in accordance with the coding rate and/or coding block length and so that the number of bits of one sequence of the parity parts falls below the number of bits of systematic part Y1 and controls bit number reduction section (109) so that the determined number of bits is obtained. Bit number reduction section (109) reduces the number of bits of systematic part Y1, and parity parts Y2 and Y3 output from separation section (108) under the control of control section (110) and decoder (111) performs turbo decoding using each sequence reduced by bit number reduction section (109).

Abstract: There is provided a down link multi-user time-space code precoding method including: a step (S401) where a base station acquires channel information on a plurality of user terminals and converts it into a channel matrix; a step (S402) for obtaining a such a conversion matrix that a matrix obtained by multiplying the channel matrix and the conversion matrix is a block diagonal orthogonal matrix; a step (S403) for obtaining a standardization factor of each user terminal by squaring the elements on the diagonal line of the block diagonal orthogonal matrix; a step (S404) for standardizing a transmitted symbol of each user by using the standardization factor; and a step (S405) for multiplying the conjugate transposed matrix and the conversion matrix of the block diagonal orthogonal matrix into standardized symbols successively from the left so as to obtain symbols after the processing and transmitting the processed symbols by the time-space code rule.

Abstract: Provided are a multi-pilot generation method and a detection method in a multi-antenna communication system. In the method, a transmission side superimposes a first preamble sequence and a third preamble sequence to generate a second preamble sequence, which is subjected to serial/parallel conversion before the first preamble sequence and the second preamble sequence are successively transmitted from a plurality of antennas by time division. A reception side receives the first preamble sequence and the second preamble sequence by a plurality of antennas, separates the third preamble sequence from the second preamble sequence by a spatial division process, and performs a pilot correlation process by using the first preamble sequence and the separated third preamble sequence.

Abstract: A transmitting apparatus capable of enhancing the certainty of data transmission of MIMO system, improving the system throughput, and providing a retransmission technique adaptive to the multi-antenna transmission. In this apparatus, a serial/parallel converting part (300) serial/parallel converts the data, which is to be transmitted, into a number nT of data substreams. A data rearranging part (301) rearranges, based on feedback information, the nT data substreams. CRC encoding parts (302) CRC encode the respective data substreams. Modulating/encoding parts (303) modulate and encode the respective corresponding data substreams. A number nT of transmission antennas (304) transmit the data substreams.

Abstract: A multiantenna communication system comprises a determining part (116) that calculates correlation values each between the channel characteristics of the resource blocks in an STBC (Space Time Block Code) and determines a combination pattern exhibiting the highest correlation; a connection distributing part (103) that maps, into a time domain, a frequency domain and a spatial domain, the STBC encoded transport data in accordance with the combination pattern determined by the determining part; a plurality of transmission antennas (107) for transmitting respective signals associated therewith; a plurality of reception antennas (108) for receiving the signals transmitted from the transmission antennas; and a connection multiplexing part (113) that extracts the signals, which belong to the same STBC, from the signals mapped into the time domain, frequency domain and spatial domain in accordance with the combination pattern determined by the determining part, and then combines the data blocks.

Abstract: A wireless communication system capable of achieving adaptive STTD (Space-time Transmit Diversity). In this system, a receiving apparatus uses a channel estimation to calculate SINR (Signal to Interference and Noise Ratio) of each of substreams in all the combinations of transmission antennas and also calculate the performance of the whole system in all the combinations of transmission antennas, thereby deciding a particular combination, which provides the best performance of the whole system, and obtaining a parameter for antenna selection. The SINR of each substream in the decided particular combination is used to decide an AMC parameter. A transmitting apparatus performs STTD and AMC based on the AMC parameter fed back from the receiving apparatus, and further selects, based on the antenna selection parameter fed back from the receiving apparatus, a particular combination of transmission antennas for performing a transmission.