摘要:
A radio communication system having a radio transmitter and a radio receiver and adopting multiple carrier modulation and code spreading modulation methods is disclosed. The radio communication system comprises a selecting unit provided in the radio transmitter or the radio receiver, for selecting an interleaving mode out of plural interleaving modes depending on radio propagation path conditions; a symbol configuration unit provided in the radio transmitter; and a symbol reconfiguration unit provided in the radio receiver. The symbol configuration unit configures information symbols to be transmitted by the radio transmitter in both time and frequency directions in a pattern according to the interleaving mode selected by the selecting unit, and the symbol reconfiguration unit reconfigures information symbols received by the radio receiver in both time and frequency directions in an inverse pattern of the pattern.
摘要:
The object of the present invention is to prevent continued reception of unreliable information symbols at the receiver apparatus 200 in the OFDM radio communication system, so that it is possible to improve transmission quality. The radio communication system according to the present invention comprises a transmitter apparatus 100 configured to estimate conditions of propagation paths used in the radio communication, arrange information symbols along the direction of the frequency axis in accordance with a predetermined pattern based on the estimated conditions of propagation paths, and transmit a radio communication signal including the arranged information symbols and a receiver apparatus 200 configured to receive the radio communication signal, and rearrange the information symbol included in the radio communication signal along the direction of the frequency axis in accordance with a reverse pattern to the predetermined pattern.
摘要:
A radio communication system having a radio transmitter and a radio receiver and adopting multiple carrier modulation and code spreading modulation methods is disclosed. The radio communication system comprises a selecting unit provided in the radio transmitter or the radio receiver, for selecting an interleaving mode out of plural interleaving modes depending on radio propagation path conditions; a symbol configuration unit provided in the radio transmitter; and a symbol reconfiguration unit provided in the radio receiver. The symbol configuration unit configures information symbols to be transmitted by the radio transmitter in both time and frequency directions in a pattern according to the interleaving mode selected by the selecting unit, and the symbol reconfiguration unit reconfigures information symbols received by the radio receiver in both time and frequency directions in an inverse pattern of the pattern.
摘要:
A transmitter used in a wireless communication system based on an orthogonal frequency division multiplexing (OFDM) scheme includes a determination unit that determines a spreading factor and an amplitude for a control channel based on at least one of signal quality information and interference information in data transmission. The transmitter also includes a multiplexing unit that multiplexes a data channel with the control channel having been code-spread based on the spreading factor and the amplitude. A modulator then modulates the multiplexed signal in the OFDM scheme for transmission as OFDM symbols.
摘要:
A signal separation device is disclosed that is able to reduce a number of calculations required when separating a received signal transmitted from transmission devices into the individual transmission signal. The signal separation device includes a signal point derivation unit that multiplies the received signal with respective elements of a unitary matrix, and derives at least one received-signal signal point on a signal constellation diagram; a definition unit that defines plural sections on the signal constellation diagram, each of the sections including a predetermined number of signal points; a detection unit that detects a received-signal section from the sections, the received-signal section including the received-signal signal point; a selection unit that selects signal points in the received-signal section as candidates of the received-signal signal point; and a determination unit that determines the transmission signals based on the selected signal points.
摘要:
A signal detection apparatus improving signal detection accuracy in a receiver for communications system complying with the MIMO scheme. The signal detection apparatus detects transmission signals sent from transmission antennas based on received signals received by receiving antennas. The apparatus includes: a first determination mechanism for determining symbol candidates of the transmission signals in sequence based on the QRM-MLD method using the received signals arranged in first order; a second determination mechanism for determining symbol candidates of the transmission signals in sequence based on the QRM-MLD method using the received signals arranged in second order that is different from the first order; and an output mechanism for outputting symbol candidates and likelihood of the transmission signals based on determination results of at least the first and the second determination mechanisms.
摘要:
The radio communication apparatus includes two or more antennas, a receiving unit for receiving a notice signal from a communication partner, two or more units for changing the number of data sequences and for coupling to the antennas according to two or more transmitting methods out of a MIMO multiplexing method, a MIMO diversity method, and an adaptive array antenna method, a selecting unit for selecting at least one out of the two or more units based on the notice signal, and a transmitting unit for notifying the communication partner of the transmission method corresponding to the selected unit.
摘要:
A receiving apparatus, a receiving method, and a radio communications system are disclosed. The receiving apparatus is for receiving CDMA signals transmitted by M antennas and received by N antennas, where M and N are positive integers. The receiving apparatus includes a multipath receiving signal demodulating unit for primary demodulation of the CDMA signals received by the receiving antennas to obtain estimated transmission signals, and for obtaining signals in a multipath environment of each path of the receiving antennas based on the estimated results. Further, the receiving apparatus includes a multipath interference canceling unit for deducting signals of the paths other than a target path from the signals received by the receiving antennas to obtain multipath interference cancelled signals. Further, the receiving apparatus includes a demodulator for secondary demodulation of the multipath interference cancelled signals.
摘要:
A disclosed receiver in a MIMO multiplexing communication system, in which plural signals are simultaneously transmitted from plural transmitting antenna branches using the same frequency, and the transmitted signals are retrieved by receiving signals at plural receiving antennas, separating the received signals and searching for proper symbol metrics for each branch, comprises a QR decomposer for QR decomposing the received signals to orthogonalize the transmitted signals; a symbol replica candidate ranking unit for subtracting surviving symbol replica candidates from the QR decomposed received signals to get remaining received signals and rank the remaining signals in the increasing order of expected branch metrics of the remaining received signals; a symbol replica candidate selector for selecting symbol replica candidates in the ranked order; a branch metric calculator for calculating the branch metrics of the selected symbol replica candidates; and a threshold comparator for comparing the calculated branch metrics with a predetermined threshold; wherein if a calculated branch metric is larger than the predetermined threshold, the branch metric and successive branch metrics are deleted without further searching.
摘要:
A receiving apparatus, a receiving method, and a radio communications system are disclosed. The receiving apparatus is for receiving CDMA signals transmitted by M antennas and received by N antennas, where M and N are positive integers. The receiving apparatus includes a multipath receiving signal demodulating unit for primary demodulation of the CDMA signals received by the receiving antennas to obtain estimated transmission signals, and for obtaining signals in a multipath environment of each path of the receiving antennas based on the estimated results. Further, the receiving apparatus includes a multipath interference canceling unit for deducting signals of the paths other than a target path from the signals received by the receiving antennas to obtain multipath interference cancelled signals. Further, the receiving apparatus includes a demodulator for secondary demodulation of the multipath interference cancelled signals.