发明名称 |
SPREAD SPECTRUM RECEIVER AND AUTOMATIC GAIN CONTROL CIRCUIT FOR IT |
摘要 |
PROBLEM TO BE SOLVED: To reduce the bit width of a demodulator without deteriorating a bit error ratio by calculating a phase from the ratio of components I and Q based on n-bit data obtained by an automatic gain circuit and differentially decoding a calculated phase to decode data. SOLUTION: Quadrature detectors 21 to 23 convert intermediate frequency signals obtained based on a received signal into quadrature base band signals. Two correlating devices 33a and 33b respectively calculate correlation between a base signal and a spread code. An automatic gain control circuit 34 fetches n(m>n)-bit data from m-bit data respectively showing the components I and Q of the correlating value outputted by the correlating devices 33 based on the number of effective bits at each symbol frequency of the base band signal. The demodulator 31 calculates from the ratio of the components I and Q based on n-bit data obtained by the circuit 34 and differentially decodes the calculated phase to decode data. |
申请公布号 |
JPH1188232(A) |
申请公布日期 |
1999.03.30 |
申请号 |
JP19970250771 |
申请日期 |
1997.09.16 |
申请人 |
UNIDEN CORP |
发明人 |
SHINOHARA YOSHINORI;SEKI KAZUHIKO |
分类号 |
H03G3/20;H04B1/16;H04B1/707;H04L27/22 |
主分类号 |
H03G3/20 |
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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