Abstract: Taking into account an optimal reception characteristic of a communication apparatus with variable directivity, the base station apparatus of the present invention has a communication apparatus with variable directivity positively accommodate a communication with a terminal in poor reception conditions, which makes it possible to reduce power of this terminal and reduce interference, thereby increasing the subscriber capacity in the system.

Abstract: S/P transform section 101a transforms transmission data A from serial data into parallel data, and outputs the parallel data to 16 QAM mapping section 102 as data to be mapped onto bits (S0 and S1) with relatively high quality. S/P transform section 101b transforms transmission data B from serial data into parallel data, and outputs the parallel data to 16 QAM mapping section 102 as data to be mapped onto bits (S2 and S3) with relatively low quality. 16 QAM mapping section 102 performs mapping on transmission data A and B on the signal space diagram of 16 QAM by Gray Coding. Then, transmission data A and B undergoes digital modulation, and is transmitted to a communicating party via antenna 105.

Abstract: A likelihood calculating section 205 calculates a likelihood of a data portion signal and outputs a weighting coefficient according to the likelihood to a multiplier 206. The multiplier 206 multiplies a data channel estimation value output from a data channel estimating section 204 by the weighting coefficient output from the likelihood calculating section 205, whereby weighting the data channel estimation value according to likelihood of the data portion signal. A combining section 207 combines a PL channel estimation value with the data channel estimation value weighted according to the likelihood of data portion signal to obtain a final channel estimation value.

Abstract: A particular data item is arranged two-dimensionally, distributed both on the frequency axis and on the time axis, by spreading in the time axis direction by means of time domain spreaders 102-1 through 102-N data converted to parallel form by an S/P section 101, and rearranging post-spreading chips on the frequency axis by shifting them step-wise in the carrier frequency upward or downward direction by means of a rearranging section 103.

Abstract: A control signal generation section 106 generates a transmission power control signal for instructing transmission power to a mobile station apparatus on the basis of a comparison result of a measured SIR with a target SIR. A transmission power control section 111 controls transmission processing to a transmission signal including the transmission power control signal generated by the control signal generation section 106 on the basis of a transmission power control signal transmitted by the mobile station apparatus. Moreover, the control signal generation section 106 and the transmission power control section 111 respectively perform the generation of the transmission power control signal and the control of the transmission processing to the transmission signal according to an appearance of a new mobile station apparatus or an appearance of a new interference source.

Abstract: Channel quality candidate generators 171-1 through 171-16 virtually increase (U) or decrease (D) the transmission power of channels A through D using mutually different patterns, and predict overall channel quality after combining each channel signal in that case. Subtracters 172-1 through 172-16 find the difference between the channel quality predicted by corresponding channel quality candidate generator 171-1 through 171-16 and a target quality, and output a difference value. A selector 173 selects the difference value with the smallest absolute value from among the difference values output from subtracters 172-1 through 172-16, and generates a TPC command to each of channels A through D based on the transmission power of channels A through D virtually increased or decreased by corresponding channel quality candidate generator 171-1 through 171-16. By this means, it is possible for a desired quality to be obtained for overall communications while reducing total transmission power on the transmitting side.

Abstract: To prevent deterioration of the reception characteristic of communication partner station without increasing the circuit scale of the radio apparatus. Amplitude of a transmission signal subjected to inverse equalization processing by an inverse equalization processor 104 that provides a characteristic, which is opposite to a distortion characteristic on the radio propagation path received at a signal receiving time, with respect to the transmission signal is controlled based on any one of a square sum of all tap coefficient values of a digital filter, which is a channel estimation value, a square root of square sum, or a sum of absolute values.

Abstract: A spreader 112 of a base station apparatus 100 spreads transmission data at a low spreading factor at which a given signal quality can be little obtained after despreading at a mobile station apparatus 101, when an error detector 137 of the mobile station apparatus 101 detects an error in despread data of received data, a data retransmission request is performed to the base station apparatus 100 and despread data is held by a despreader/combiner 136. After that, the mobile station apparatus 101 repeats processing for combining the held data with the retransmitted data subjected to despreading until the time when an error-undetected state comes. This makes it possible to increase transmission efficiency, suppress transmission power extremely, and improve diversity performance to transmit data from a plurality of antennas.

Abstract: An assignment section 101 determines communication resource assignment to communication terminals based on a transmission rate at which communication is possible for each subcarrier of each communication terminal, and instructs a buffer section 102 to output forward transmission data. In addition, the assignment section 101 instructs a frame creation section 103 to perform forward transmission data symbolization, and also outputs a signal indicating communication resource assignment to each communication terminal. The buffer section 102 holds forward transmission data, and outputs forward transmission data to the frame creation section 103 in accordance with instructions from the assignment section 101. The frame creation section 103 symbolizes a resource assignment signal and transmission data to create a frame, which it outputs to a spreading section 104.

Abstract: After digital modulation by digital modulation section 101, OFDM symbols (first OFDM symbol group) converted to parallel by S/P conversion section 102 are output to mapping section 103, where of a plurality of subcarriers on which the first OFDM symbol group is superimposed, the OFDM symbols superimposed on a predetermined number of subcarriers are set to “0” to expand thereby the OFDM symbol space. As many OFDM symbols as those of the first OFDM symbol group are selected in ascending order of peak power from among symbol patterns in this space, the first OFDM symbol group is associated with this selected OFDM symbol, this associated and selected OFDM symbol is output, this selected OFDM symbol is subjected to an inverse fast Fourier transform by IFFT section 104 and then transmitted.

Abstract: The replica signals generated in a replica generation circuit 306 are sent to a combining circuit 203 through a bus 204. In the combining circuit 203, the above replica signals are input from each circuit board X through Z for combining of replica signals. In a channel allocation control circuit 202, a new channel is allocated so that the relations between the order and likelihood are almost uniform among subsets, based on likelihood information reported from each circuit board X through Z which is a subset; accommodated symbol rates and services (voice signals and packet signals); target SIRs and so on. Thereafter, the allocation control signals are sent to each circuit board X through Z.

Abstract: The synchronizing apparatus includes a block for detecting a code from an input signal, a block for detecting from the code the variable points of the code at several times as high as the symbol rate, a block for calculating a histogram of the detected variables of the code to time, and a block for deciding that the phase number at which the calculated histogram takes the maximum value is a symbol synchronization point. This synchronizing apparatus detects the zero-cross points of an intermediate frequency band signal at N times as high as the symbol rate. It also calculates a histogram of detected time (0 to N−1). The time (0 to N−1) at which the histogram is the maximum within a predetermined detected time is selected as a symbol clock, and thereby symbol synchronization is established.

Abstract: The fading correlation monitor 103 detects an angle spread of the communication terminal apparatus 200-1 and decides whether the angle spread has a larger or smaller relationship with a preset threshold value. When the estimated angle spread is smaller than the threshold value, the interference wave is suppressed by carrying out directive reception which is carried out by an AAA receiver 106 as well as performing directive transmission which is carried out in a transmitting circuit 122. While, when the estimated angle spread is larger than the predetermined value, the distortion of the signals due to the fading is compensated by carrying out diversity receiving which is carried out in a diversity receiver 107 as well as performing diversity transmission which is carried out in a diversity transmitter 123. On account of this, even when the fading correlation is small, it is possible to carry out a radio communication with a satisfactory communication quality.

Abstract: Taking into account an optimal reception characteristic of a communication apparatus with variable directivity, the base station apparatus of the present invention has a communication apparatus with variable directivity positively accommodate a communication with a terminal in poor reception conditions, which makes it possible to reduce power of this terminal and reduce interference, thereby increasing the subscriber capacity in the system.

Abstract: In an adaptive modulation communication system that adaptively varies a modulation scheme for each transmit unit, a transmitting-side apparatus sets different error detecting units corresponding to bit position, and transmits data subjected to error detecting processing on a different error detecting unit basis corresponding to bit position, and a receiving-side apparatus performs demodulation independently for each of the error correcting units using different demodulation patterns to obtain received data.

Abstract: Analysis filter splits an input signal into M frequency bands. Sampling rate converter 102 downsamples split signals at a sampling rate of 1/M times. Training processing section 105 receives a known training signal and provides the training processing to the signal for the distortion correction. Sampling rate converter 103 upsamples a corrected signal. Synthesis filter 104 reconstructs upsampled signals into an original signal.

Abstract: A separator 109 separates an output signal output from a demodulator 108 into receive data and an OK signal or NG signal, outputs the receive data, and outputs the OK signal or NG signal to a transmission method switching determination section 110. The transmission method switching determination section 110 stores the number of times an OK signal or NG signal is received, determines whether or not the transmission method is to be changed according to the frequency of stored OK signals and NG signals, and based on the result of this determination, outputs to a transmission method switching controller 111 an instruction for carrying out or not carrying out a change of transmission method.

Abstract: The maximum delay time of delayed waves is estimated by a channel estimation section (106). A coding section (101) performs convolutional coding of transmit data with a constraint length determined adaptively based on the multipath maximum delay time estimated by the channel estimation section (106), and transmits the transmit data, and also notifies information indicating the convolutional code constraint length to the receiving side. The receiving side simultaneously performs Viterbi decoding and equalization with a UDMV (153) in accordance with the constraint length reported by the transmitting side, and obtains received data. By this means it is possible to improve error correction capability in the UDMV without enlarging the scale of the apparatus.

Abstract: The present invention relates to a code generating method for combining an orthogonal code for CDMA having a specific spreading factor and its polarity inverted spreading code to generate another spreading code having a larger spreading factor than that of the spreading code. And the present invention relates to a code selecting method for combining an orthogonal code for CDMA having a specific spreading factor and its polarity inverted spreading code to generate another spreading code having a larger spreading factor than that of the spreading code, then to assign the generated orthogonal code for a user in order of users having an orthogonal code of small spreading factor.

Abstract: In the receiver of the present invention, it is after weighting every observed value with corresponding likelihood at every observation points that a least square method is utilized as a linear prediction to the observations, in order to improve the accuracy of the linear prediction by making the influence of the probable observed values to the prediction result larger. The present invention can improve the accuracy of received signal correction in a receiver, by making a linear prediction more reliable, which is applied for frequency offset compensation, phase shift compensation, synchronization shift adjustment, combined diversity and other signal values estimation.