摘要:
A path searcher used in a receiver includes a power delay profile generating unit configured to generate a power delay profile based on a signal received by the receiver, a sidelobe generating unit configured to identify a sidelobe component of a path contained in the power delay profile based on a response characteristic of a band-limiting filter of the receiver, a sidelobe removing unit configured to remove the sidelobe component from the power delay profile to produce a corrected power delay profile, and a path timing detection unit configured to detect a path timing based on the corrected power delay profile.
摘要:
A noise power estimation apparatus is disclosed. The noise power estimation apparatus includes: a part for calculating correlation between a received signal and a pilot signal so as to obtain a received power of the pilot signal for each path; a part for removing a multipath interference component from the received power of the pilot signal by using a predetermined power ratio between the pilot signal and a data signal so as to obtain a corrected received power of the pilot signal; a part for estimating an estimated total power of the pilot signal and the data signal included in the received signal based on the corrected received power and the predetermined power ratio; and a part for subtracting the estimated total power from a total power of the received signal so as to obtain a noise power.
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:
The wireless base station 10 includes a multiplexing units 13 generating user data; a channel assignment control unit 14 for selecting subcarrier groups from a plurality of subcarriers on two carriers, forming two wireless frames including subchannels generated from the subcarrier groups, and time-division multiplexes and sets the user data and control data to the two wireless frames; and a transmitting and receiving unit 16 transmitting a wireless signal including the wireless frames, wherein the channel assignment control unit 14 divides all of the subchannels in the two wireless frames into areas of destination sectors, stores the control data only in the corresponding area, and stores the user data in all of the areas in the two wireless frames.
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 signal reception device is disclosed that is capable of detecting symbol synchronization timing with high precision in accordance with a condition of a propagation path even in an environment involving multi-path interference. The signal reception device adopts an OFCDM transmission scheme or a multi-carrier transmission scheme. The signal reception device includes a received signal information calculation unit to calculate received signal information representing a signal reception condition of a received signal; an output combination unit to combine correlation values in a predetermined section obtained by correlation detection based on the received signal information; and a symbol timing detection unit to detect a symbol synchronization timing based on the combined value.
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 pilot extract section 14 extracts a pilot signal from received signal. An adder 21 in-phase adds a plurality of correlated values of pilot signals for respective subcarriers. Delay devices 201-1 to 201-6 temporarily maintain one in-phase added value. Multiplier 202-1 to 202-6 multiplies a predetermined coefficient to the in-phase added value that is output from the delay device. The predetermined coefficient reflects the result, which is obtained by correcting for multiple times the difference of channel variation in the different subcarriers that is generated when noise power per one subcarrier is calculated. Each of the multiplying results is added by an adder 24, and is squared by a square device 25. A cumulative adder 26 cumulative-adds the squared values for the whole subcarrier. A multiplier 203 averages by multiplying predetermined values to the cumulative-added values. Having such configuration, even if the correlation between adjacent subcarriers becomes lower by frequency selective fading, the accuracy for estimating noise power can be improved.
摘要:
A pilot extract section 14 extracts a pilot signal from received signal. An adder 21 in-phase adds a plurality of correlated values of pilot signals for respective subcarriers. Delay devices 201-1 to 201-6 temporarily maintain one in-phase added value. Multiplier 202-1 to 202-6 multiplies a predetermined coefficient to the in-phase added value that is output from the delay device. The predetermined coefficient reflects the result, which is obtained by correcting for multiple times the difference of channel variation in the different subcarriers that is generated when noise power per one subcarrier is calculated. Each of the multiplying results is added by an adder 24, and is squared by a square device 25. A cumulative adder 26 cumulative-adds the squared values for the whole subcarrier. A multiplier 203 averages by multiplying predetermined values to the cumulative-added values. Having such configuration, even if the correlation between adjacent subcarriers becomes lower by frequency selective fading, the accuracy for estimating noise power can be improved.