发明名称 |
IMPROVED EXCITATION SIGNAL BANDWIDTH EXTENSION |
摘要 |
An apparatus for generating a high band extension of a low band excitation signal (eLB) defined by parameters representing a CELP encoded audio signal includes the following elements: upsamplers (20) configured to upsample a low band fixed codebook vector (uFCB) and a low band adaptive codebook vector (uACB) to a predetermined sampling frequency. A frequency shift estimator (22) configured to determine a modulation frequency (Ω) from an estimated measure representing a fundamental frequency (F0) of the audio signal. A modulator (24) configured to modulate the upsampled low band adaptive codebook vector (uACB↑) with the determined modulation frequency to form a frequency shifted adaptive codebook vector. A compression factor estimator (28) configured to estimate a compression factor. A compressor (34) configured to attenuate the frequency shifted adaptive codebook vector and the upsampled fixed codebook vector (uFCB↑.) based on the estimated compression factor. A combiner (40) configured to form a high-pass filtered sum of the attenuated frequency shifted adaptive codebook vector and the attenuated up-sampled fixed codebook vector. |
申请公布号 |
EP2502230(A4) |
申请公布日期 |
2013.05.15 |
申请号 |
EP20100831865 |
申请日期 |
2010.07.05 |
申请人 |
TELEFONAKTIEBOLAGET L M ERICSSON (PUBL) |
发明人 |
SVERRISSON, SIGURDUR;BRUHN, STEFAN;GRANCHAROV, VOLODYA |
分类号 |
G10L21/02;G10L19/04;G10L19/12 |
主分类号 |
G10L21/02 |
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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