Low data rate speech encoder with mixed excitation

Details Low data rate speech encoder with mixed excitation Low data rate speech encoder with mixed excitation

1995-06-01

1997-09-16

Safourek, Benedict V.

Data processing: speech signal processing, linguistics, language

Speech signal processing

For storage or transmission

704222, G10L 900

Patent

active

056689250

ABSTRACT:
A speech signal has its characteristics extracted and encoded (16), transmitted over a limited-data-rate path (18) and is decoded (20) and synthesized (22) at the receiving end. The characteristics include line spectral frequencies (LSF), pitch and jitter. The LSF are extracted by autoregression, and splitvector quantized (SVQ) in a single frame, and, in parallel, in blocks of two, three and four frames. The SVQ codes have equal length and are evaluated for distortion in conjunction with a threshold. The threshold is varied in such a manner as tend to select for transmission those codewords which maintain a constant data rate into a transmit buffer. A single-bit jitter bit, and encoded pitch value, are product coded with the selected LSF codeword, and all are transmitted over the data path (18) to the receiver. The receiver decodes the characteristics, and controls a pitch generated (1226) in response to the pitch value and a random pitch jitter in response to the jitter bit. Two sets of line spectrum filters receive random noise and the pitch signal, respectively. The filtered signals are modulated by multipliers (1222, 1230) controlled by the LSF codes, and the filtered signals are summed and applied to a final LSF-controlled filter.

REFERENCES:
patent: Re34247 (1993-05-01), Atal et al.
patent: 4718087 (1988-01-01), Pamamichalis
patent: 4899385 (1990-02-01), Ketchum et al.
patent: 4963030 (1990-10-01), Makur
patent: 5233660 (1993-08-01), Chen
patent: 5307441 (1994-04-01), Tzeng
patent: 5353373 (1994-10-01), Drogo De Iacovo et al.
patent: 5384891 (1995-01-01), Asakawa et al.
patent: 5481642 (1996-01-01), Shoham
Final Report for Contract F30602-89-C-0118 entitled, "Improved Speech Compression Algorithm".

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