| 摘要 |
<p>When a spread spectrum signal and various kinds of noise arrive at a receiver in a mixed state, the SN ratio of the received and demodulated signal and the frequency band utilization efficiency of the SS system are improved by separating the noise and discriminatingly detecting the frequency components of the noise. Specifically, the received frame signal r(t) containing noise is subjected to reverse spectrum spreading by using the same spread code sequence m(t) of a desired station, DC components are removed from the reverse-spread output u(t), a respread product output is produced by again multiplying the output u(t) by the spread code sequence m(t), N analysis frequency components Wi which are i times the frame rate which is the DFT conversion analysis result of the product output, the noise waveform components contained in the received signal are presumably detected by solving simultaneous linear equations with N unknowns constituted by using the set of Wi and noise frequency components Xj which are obtained by performing DFT conversion analysis only on the noise. The unknowns are the set of Xj.</p> |
