Matsushita Electric Industrial Co., Ltd.

Kiyotaka Nagai

Yasushi Nakajima

Naoki Ejima

Tatsuya Adachi

Takafumi Ueno

Masataka Nikaido

Hiroshi Fukukita

Masami Kawabuchi

Michihiro Matsumoto

Hiroshi Saito

Ryoji Suzuki

Akira Fukumoto

Minoru Toyoda

Masahiko Hatanaka

Akitoshi Yamada

Daisuke Mori

Jun-ichi Sato

Hideo Shibuya

Tomoaki Abe

Hikaru Usami

Provided is a complex exponential modulation filter bank which can reduce quantity of arithmetic operation, and can realize low electric power consumption or speeding-up. This complex exponential modulation filter bank has a step of calculating a first intermediate signal from an input signal, a step of calculating a second intermediate signal from the first intermediate signal, a step of calculating a third intermediate signal from the second intermediate signal with fast Fourier transform, and a step of calculating a complex band output signal from the third intermediate signal.

Signal analyzing method, signal synthesizing method of complex exponential modulation filter bank, program thereof and recording medium thereof

There is provided an audio signal subband encoder which attains improved quality of sound by controlling allocation of the number of quantization bits to subband signals on the basis of an evaluation function combining the noise-to-mask ratio criterion with noise-to-signal ratio criterion in order to lessen the influence of the application error of the auditory masking rule such as the aliasing distortion of subband filters.

Audio signal subband encoder

An audio subband encoded signal decoder which, when an error occurs in an audio subband encoded signal of a plurality of pieces of data, conceals the error in accordance with the contents of the data involving the error and the occurrence of the error in consideration of the degree of influence on a possible reproduced sound quality to thereby improve the sound quality.

Audio subband encoded signal decoder

This invention relates to a time code recording and reproducing apparatus for recording and reproducing time codes corresponding to a digital signal. Time code converting means (100) converts a first time code into a second time code. A frame phase which occurs during the recording of input information is determined by frame timing generating means. A phase difference between a frame of the second time code and a recording frame is detected by phase difference detecting means (103). Phase difference correcting means (104) outputs a third time code on the basis of the detected phase difference. The input information is recorded together with the third time code. Thereby, the recording can be performed while the relation of the correspondence between the input information and the time code is held. In addition, the reproduction can be performed.

Time code recording or reproducing apparatus and time code converter

In an error detection and correction method, when decoding second codewords of doubly encoded information codes, the second codewords, which are considered to have a correlation with the occurrence of burst errors, are classified into groups on the basis of the decoding states of first codewords of the doubly encoded information codes, and the second codewords are decoded sequentially in the order of a group having lower error misdetection probability and on the basis of the decoding states of the second codewords, namely, the error occurrence states, up to that time, thereby enhancing the error detection capability.

Error detection and correction method

An echo canceller includes means for reducing correlation in a receiving side input signal based on a linear prediction model by regarding the receiving side input signal as an output signal of the linear prediction model. This means for reducing correlation is provided in a form suitable for hardware implementation, and thus, a convergence rate for the receiving side input signal having strong correlation as a speech signal can be improved without substantially increasing the number of calculations or the amount of memory.

Echo canceller

In a speech analysis and synthesis (composing) method, a phoneme transition waveform is generated to smoothly couple phoneme PHA to PHB having different pitch periods. The method involves obtaining the differential value (difference phoneme .DELTA.PH or difference phoneme .DELTA.PHI and difference clock or pitch period), and in composition merely adding phoneme PHA and difference phoneme .DELTA.PHI and clock period and difference clock period.

Voice analysis composing method

An ultrasound diagnostic apparatus includes a linear array of piezoelectric transducers or plates with a width-to-thickness ratio of less than 0.8 and a control circuit which includes a transmitter and a receiver. The transmitter comprises a plurality of transmitting channels each including a local oscillator for generating an ultrasonic pulse in response to a clock signal. The plurality of such ultrasonic pulses are applied through a switching network to a selected group of successively arranged piezoelectric transducers to transmit a beam of ultrasonic energy into a human body. Each of the ultrasonic pulses is phase shifted and amplitude modulated with respect to the ultrasonic pulses of the other transmitting channels to provide phase and amplitude taper which results in a narrow width beam through the depth of the body. The ultrasonic energy returned from discontinuities between different tissues is detected by the activated transducers and applied through the switching network to the receiver in which each of the return signals is phase shifted and amplitude modulated with respect to the other signals to provide an output signal which is displayed on a cathode ray tube screen.

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Osaka, Japan

Kiyotaka Nagai