Mitsubishi Electric Corporation

Naosuke Ito

Jun Ido

Daisuke Shimbo

A wireless communication device includes a transmitter that is provided in a rotary part of a rotary device and transmits a wireless signal; a receiver that is provided in a stationary part of the rotary device, receives the wireless signal, and calculates a communication quality level based on the wireless signal; and processing circuitry to determine a communication cycle based on the communication quality level so that the communication cycle synchronizes with a cycle as a multiple of a rotation cycle of the rotary part by an integer greater than or equal to 1, and to make timing of the communication between the transmitter and the receiver follow the rotation cycle by increasing or decreasing the communication cycle so that the communication quality level increases.

Wireless communication device and wireless communication method

A communication device includes: an acquisition unit that acquires first position information indicating a first position of the communication device and first position error information indicating an error of the first position; a reception unit that receives second position information indicating a second position of a communication device and second position error information indicating an error of the second position acquired by the communication device; a first calculation unit that calculates a first arrival direction and a first arrival direction error based on one or more pieces of information out of the first position information and so on; a second calculation unit that calculates a second arrival direction; and a judgment unit that makes the second calculation unit revise the second arrival direction based on the first arrival direction when the first arrival direction error is smaller than a first threshold value.

Communication device and control method

In receiving radio waves from a transmitter by an array antenna, and estimating an arrival direction of a direct wave, delay times of the arriving waves are estimated () by means of a super-resolution process based on transmission channel estimation results, an arriving wave component corresponding to the delay time having been determined to be equal to or longer than a threshold value is removed () from the transmission channel estimation results, arriving wave components after the removal are separated from each other to extract direct wave components (), and an arrival angle is estimated (). The arrival direction of the direct wave can be accurately estimated in an environment where delayed waves of short delay times are present. Also, the amount of calculation is small even when the super-resolution process is performed.

Receiving apparatus and receiving method, and program and recording medium

The present invention is provided with: a CIR generating unit which generates an channel impulse response from a received signal; a CIR variation detection unit which uses a plurality of channel impulse responses generated from a plurality of different sections of the received signal by the CIR generating unit to detect an amount of variation in the channel impulse response; an equivalent width control unit which determines an equivalent width corresponding to a signal length used in equalization of the received signal such that the equivalent width is shortened as the amount of variation in the channel impulse response increases; and a waveform equalization unit which uses the channel impulse response generated by the CIR generating unit to equalize the received signal over the equivalent width determined by the equivalent width control unit and generate a demodulated signal.

Equalizer device, receiver device and equalization method

A reception device includes signal receiving units that generate received signals from signals obtained by receiving a transmitted signal at antennas, signal processing units that perform processes of generating received frequency domain signals by transforming the received signals to signals in the frequency domain, calculating channel impulse responses of the received signals, calculating estimated received signals from the channel impulse responses, and calculating residual error weights with values that decrease with increasing differences between the received signals and the estimated received signals, a combining ratio calculation unit that calculates combining ratios for the received frequency domain signals such that the ratios decrease as the residual error weights decrease, a diversity combining unit that combines the received frequency domain signals according to the combining ratios to generate a diversity combined signal, and an inverse Fourier transform unit that transforms the diversity combined signal to a time domain signal.

Reception device and reception method

This equalization device and method, while preventing an expansion of circuit size, enable high-speed detection of a CIR in order to effectively achieve frequency domain equalization even when the phase of the received signal is significantly different from the phase of the known signal, and when the transmission channel has large temporal variations. A reference signal extraction unit () extracts both a real part component and an imaginary part component from the portion of the received signal including the known signal. A CIR detection filter unit () filters the known signal to generate a first processed signal and a second processed signal, detects real part filter coefficients by updating a first filter coefficient used in filtering the known signal in such a way that the first processed signal converges to the real part component, and detects imaginary part filter coefficients by filtering the known signal in such a way that the second processed signal converges to the imaginary part component. A CIR output unit () uses either the real part filter coefficients or the imaginary part filter coefficients to identify the channel impulse response.

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Tokyo, Japan

Naosuke Ito