发明名称 |
Low bit rate vocoder means and method. |
摘要 |
<p>Efficient coding speech information (52, 100) for low rate (e.g., 600 bps) channels (18) using a four frame superframe (SF) includes: (1) coding spectral information using alternative quantizers one of which is chosen for each superframe so that 3 bits/SF identify the optimal quantizer and 28-32 bits/SF contain the quantized spectral information; (2) coding pitch using 5 bits/SF if voiced and if unvoiced assigning the pitch bits to error correction; (3) coding energy using 9-12 bits/SF by a 4d vector quantizer (4dVQ); and (4) coding voicing using 3-4 bits/SF by a 4d VQ, for a total of 54 bits/SF including 1 sync bit and 0-1 error correction bits. When combined with a unique perceptual weighting scheme, output speech (192) quality comparable to that of vocoders operating at almost four times the channel (18) capacity is obtained. <IMAGE></p> |
申请公布号 |
EP0523979(A2) |
申请公布日期 |
1993.01.20 |
申请号 |
EP19920306479 |
申请日期 |
1992.07.15 |
申请人 |
MOTOROLA, INC. |
发明人 |
FEETE, BRUCE ALAN;JASKIE, CYNTHIA ANN |
分类号 |
G10L19/00;G10L19/06;H04L1/00 |
主分类号 |
G10L19/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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