Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Matshushita Electric Industrial Co., Ltd.

Yasutaka Uramoto

Tomohiro Yui

Koji Suzuki

Yoshinao Kawai

Masatoshi Matsushita

Nobuhiro Takagi

Yukiteru Murao

Kouji Kanamori

Atsushi Taguchi

Tomio Aida

The radio receiving apparatus includes an adaptive receive filter capable of detecting an interference wave and an out-of-band noise level correctly and improving reception performance. The radio receiving apparatus has a plurality of filters, a received signal power meter that measures the overall received signal power, a calculator that performs calculation that associates the measured received signal power with an output of AGC, an interference power meter that measures signal power in a frequency band outside a necessary band of the received signal, a comparator that compares the calculation result by the calculator with a specific threshold, and switches that select a filter to be adopted from the plurality of filters based on the outputs of comparators. The radio receiving apparatus detects adjacent interference based on signal power in the frequency band outside the signal band and detects the noise level based on the power level at an antenna end.

Radio receiving apparatus

The dynamic DC offset canceling apparatus includes: sectionthat detects dynamic DC offset in longest overlapping part sequences from the differences between the sampling values of a first longest overlapping part sequence and the sampling values of a second longest overlapping part sequence, the first longest overlapping part sequence and the second longest overlapping part sequence being overlapping part sequences in a training sequence of the received signal; sectionthat detects dynamic DC offset outside the longest overlapping part sequences from the difference between an average value of sampling values of a received signal which exists in a burst before the first longest overlapping part sequence, and an average value of sampling values of a received signal which exists in a burst after the second longest overlapping part sequence; and sectionthat adaptively subtracts a DC offset value from the received signal based on these results.

Dynamic DC offset canceling apparatus and dynamic DC offset canceling method

A DC offset cancel circuit includes an analog adderto whose one input a baseband analog signal output from a high-frequency reception section is input and to whose other input an analog correction signal output from a D/A converteris input, and which corrects the reference voltage value of the baseband analog signal analogically to cancel a DC offset, an adderwhich has the output of the A/D converteras its one input and subtracts the lower bits of a sample value stored in a memoryto be described later as a DC offset value from the input value and outputs the resultant value, a control circuitwhich outputs an output digital value of the A/D converteras a sample value to the memoryand a D/A converterwhich converts a digital value of the upper bits of a sample value stored in the memoryto an analog correction signal and outputs the analog correction signal to the analog adder

DC offset cancel circuit

An A/D converter apparatus for converting an analog signal output from an anti-aliasing filter into a digital signal, a sinc filter for removing a frequency component corresponding to an aliasing noise generated by down-sampling, a first decimator for down-sampling a signal output from the sinc filter, a low pass filter for removing a frequency component corresponding to an aliasing noise generated by down-sampling, a second decimator for down-sampling a signal output from the low pass filter, and a high pass filter for removing a dc component from a signal output from the second decimator are disclosed.

A/D converter apparatus and D/A converter apparatus including a digital filter

Growing community of inventors

Kanagawa, Japan

Yasutaka Uramoto