发明名称 |
SINGLE SIDE-BAND MODULATION SYSTEM FOR USE IN DIGITALLY IMPLEMENTED MULTICARRIER TRANSMISSION SYSTEMS |
摘要 |
A communication system having a modulation system for transmitting a symbol set via a single side-band modulated carrier and a demodulation system for recovering the in-phase and quadrature signals from the modulated carrier. The modulation circuit receives M symbol values and generates M time domain samples for each of the in-phase and quadrature signals. The in-phase and quadrature signals can then be combined to generate the single side-band modulated carrier. The modulation circuit includes a transform circuit for generating M transformed symbol values by computing the transform of the M symbol values. A polyphase filter bank having 2M FIR filters is used to process the output of the transform circuit. Each filter has g taps, where g is an integer greater than 1. The outputs of the polyphase filters are combined with the outputs of the polyphase filters generated from a previously received set of M symbols to generate the M time-domain signal values of the in-phase signal. The quadrature signal is generated by a similar circuit having two additional elements. The demodulation circuit recovers symbol sets from the in-phase or quadrature signals generated from M received time-domain signal values. The demodulator includes a memory for storing the 2M most recently received time-domain values, a polyphase filter bank, a polyphase processing circuit, and a transform circuit. The demodulation circuit for recovering a symbol set from the quadrature signal is similar to that for recovering the symbol set from the in-phase signal, except that the polyphase processor combines the outputs of the polyphase filters according to a different set of relationships and the sign of every other output from the transform is changed. |
申请公布号 |
EP1012964(A1) |
申请公布日期 |
2000.06.28 |
申请号 |
EP19970926623 |
申请日期 |
1997.05.17 |
申请人 |
AWARE, INC. |
发明人 |
SANDBERG, STUART, D.;TZANNES, MICHAEL |
分类号 |
H03C1/60;H03D1/00;H04L27/02;H04L27/26 |
主分类号 |
H03C1/60 |
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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