发明授权
- 专利标题: Non-coherent digital FSK demodulator
- 专利标题(中): 非相干数字FSK解调器
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申请号: US688429申请日: 1996-07-30
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公开(公告)号: US5748036A公开(公告)日: 1998-05-05
- 发明人: Tsai-Pao Lee , Kwang-Cheng Chen , Chin-Lin Yang
- 申请人: Tsai-Pao Lee , Kwang-Cheng Chen , Chin-Lin Yang
- 申请人地址: TWX Hsinchu
- 专利权人: United Microelectronics Corporation
- 当前专利权人: United Microelectronics Corporation
- 当前专利权人地址: TWX Hsinchu
- 主分类号: H04L27/148
- IPC分类号: H04L27/148
摘要:
A non-coherent frequency shift keying (FSK) demodulator, for receiving a N-ary FSK modulated input signal, demodulating the signal to obtain output data, in which the N-ary FSK modulation has N symbols, and the output data is constructed by a plurality of symbol intervals. The demodulator includes an A/D converter for converting the input signal in digital form, in which, for the A/D converter sampling, a sampling number M of every symbol interval satisfies an equation M.gtoreq.2K+1, wherein K is the interval number of a carrier of the input signal in each symbol interval. N filter arrays each respectively receive the input signals in digital form, and each one of the N filter arrays has a filtering frequency band, respectively, corresponding to spectrums of N symbols in N-ary FSK modulation. N downsamplers each receive the input signal from the corresponding filter array and reduce the sampling number of the input signal to make each symbol interval include only one sample value. N absolute-value generators each receive the input signal from the corresponding downsampler and calculate the absolute value of the sample value of the input signal. A maximum detector receives the outputs of the absolute value generators and detects the maximum in the outputs to decide the symbols represented by each symbol interval, so as to output data.
公开/授权文献
- US4658284A Image forming apparatus 公开/授权日:1987-04-14