Hitachi-kokusai Electric Inc.

Daiki Hoshi

Tatsuhiro Nakada

Kei Ito

Hiroki Kato

In a base station, a signal synchronization unit detects a received timing of a signal from a mobile station. A correlation position protection unit corrects the received timing on the basis of time from a transmitting timing at which a signal transmitting operation to the mobile station is started to the received timing. A transmitting timing generation unit generates, on the basis of the received timing after the correction, a transmitting timing at which a subsequent signal transmitting operation to the mobile station is started. Further, an FB frame generation unit generates frame period information that indicates a correction value by the correlation position protection unit, and a transmitting processing unit transmits, to the mobile station, a signal including the frame cycle information in response to the generation of the transmitting timing.

Wireless communication system and wireless communication device

A reception device including reception antennas is provided. In the reception device, a demodulation unit is configured to calculate, for each of a plurality of antenna combinations of the reception antennas, log likelihood ratios of coded bits of error correction code obtained from reception signals of the reception antennas. A mutual information amount calculation unit is configured to calculate an average mutual information amount based on the log likelihood ratios corresponding to each of the antenna combinations. An antenna combination selection unit is configured to output determination information for specifying one of the antenna combinations for which the average mutual information amount is the maximum. A signal selection unit is configured to select the log likelihood ratios corresponding to the specified antenna combination based on the determination information, and a decoding unit is configured to decodes the selected log likelihood ratios.

Reception device and wireless communication system

A wireless communication device suppresses increase in computation scale when applying maximum likelihood detection to a multi-level modulation scheme. Units calculate a likelihood, bit log-likelihood ratio, and mutual information content for the separation result of a received signal on the basis of the signal point of a reference selected from among a plurality of signal points that a transmitted signal can assume. A transmission candidate point selection unit selects signal points in a number that corresponds to the mutual information content as transmission candidate points from among the plurality of signal points in ascending order of distance to 0 and distance to 1 for each modulation bit that constitutes the signal point of the reference. A reception candidate point that is a candidate for the received signal is calculated. An external LLR calculation unit calculates the bit log-likelihood ratio by an MLD method.

Wireless communication device and wireless communication method

An object of the present invention is to generate a soft estimation value where missing of bit information is avoided and to implement turbo equalization processing in a wireless transmission apparatus and a wireless transmission system where termination processing is not performed in an error correction coding part and interleave processing over frames is performed. A wireless transmission system of the present invention includes a transmission apparatus and a reception apparatus. The transmission apparatus includes an error correction coding unit, a first interleave unit, a second interleave unit, and a digital modulation unit. The reception apparatus includes a unit that detects a reception signal, a demapper unit, a second deinterleave unit, a unit to store a received bit logarithm of likelihood ratio in a frame buffer, a frequency interleaver data extraction part that extracts data of a predetermined period, a decoding part, and a hard decision part.

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Tokyo, Japan

Daiki Hoshi