Nec Corporation

Shingo Kikuchi

Yoshikazu Kakura

Shousei Yoshida

Motoya Iwasaki

Akihisa Ushirokawa

Takashi Mochizuki

Masayuki Kimata

The present disclosure eliminates the need for a buffer large enough to store a MAC PDU for the CRC check and eliminates processing delay involved in outputting data to, and inputting data from, the buffer. A wireless communication device analyzes and buffers an RLC data PDU, which is a data processing unit in the Radio Link Control layer (RLC layer), in the RLC layer without waiting for the completion of error detection processing, which is performed in the Medium Access Control layer (MAC layer), for a data processing unit (PDU) in the MAC layer. In the RLC layer, the wireless communication device references the result of the error detection processing for the MAC PDU performed in the MAC layer and creates an RLC Service Data Unit (RLC SDU) using an error-free RLC data PDU.

Wireless communication device and data reception method

A wireless communication system includes a base station and a terminal station. The base station extracts paths that have a power level that exceeds a predetermined threshold value from delay profiles of the terminal station as available paths, selects a path having a maximum power or a first path from the available paths as a reference path, calculates a time difference between an arrival time of the reference path and a predetermined maximum arrival time, and transmits a result to the terminal station as a transmission timing control signal. The terminal station adjusts the transmission timing to the base station according to the time difference. The base station transmits the transmission timing control signal only when the base station detects the reference path.

Wireless communication system, base station, and wireless communication method

A communication system includes a first radio communication apparatus and a second radio communication apparatus that includes multiple antennas. The first radio communication apparatus receives transmission signals transmitted from multiple antennas as reception signals, acquires a predetermined parameter for each antenna based on the reception signals, creates control information for causing the second radio communication apparatus to control transmission signals so that the parameter becomes a predetermined target value for each antenna, compares absolute values of differences between each acquired parameter and the target value, and transmits control information corresponding to the reception signal for which the absolute value is large to the second radio communication apparatus with priority over control information corresponding to the reception signal for which the absolute value is small. The second radio communication apparatus receives control information from the first radio communication apparatus and controls transmission signals for each antenna according to the control information.

Communication system, radio communication apparatus, and communication method

A wireless communication system according to an exemplary aspect of the present invention is a wireless communication system which performs wireless communications between a first wireless communication device and a second wireless communication device, wherein the first wireless communication device includes: a delay profile calculation unit for calculating a delay profile by calculating a correlation value for a received signal; a valid path detection unit for detecting a valid path using the delay profile and forcibly detecting a valid path when there is no path satisfying a condition of the valid path; and a forcible valid path notification unit for notifying that the valid path is forcibly detected.

Wireless communication system, wireless communication device, and valid path detection method therefor

In a method for adaptive transmission timing control, the overlooking of a base path at the side of the base station that occurs when the transmission timing offset amount changes to the extent of falling outside the current delay-profile calculation range, and the side of the mobile station fails to demodulate the control information that contains the transmission timing offset amount, is prevented. A limit is put on the transmission timing offset amount applied in a single transmission timing control iteration. Together with setting the transmission timing offset value such that the main component of the delay profile calculated from the pilot signal transmitted with offset transmission timing falls within the time range of when the current delay profile was calculated, the time range for calculating the next delay profile is shifted such that a delay profile calculated from the pilot signal transmitted with offset transmission timing falls within the shifted range, starting at the earliest component.

Adaptive transmission timing control method, wireless communication system and wireless communication device

A radio communication system for quickly selecting an optimum transmission mode in accordance with the quality and situation of a propagation path is provided. The system comprises first and second radio communication apparatuses capable of radio-communicating with each other. The first radio communication apparatus comprises a propagation path environment estimator for outputting the estimation result as propagation path environment information, a propagation path quality estimator for outputting the estimation result as propagation path quality, and a transmitter for transmitting both the informations to the second radio communication apparatus. The second radio communication apparatus comprises a transmission mode selector for selecting one of the transmission modes used for communicating with the first radio communication.

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Tokyo, Japan

Shingo Kikuchi