| 摘要 |
<p>PURPOSE:To improve reception quality by eliminating phase difference between transmission and reception carriers in a data demodulation circuit for spread spectrum communication. CONSTITUTION:An in-phase axis reception signal and an orthogonal axis reception signal are multiplied by PN codes PNI (t), PNQ (t), respectively, and averaging processing is applied to them at averaging parts 20, 22, 24, and 26, then, correlation can be calculated. By applying such correlative processing. rhok0costheta, -rhok0sintheta, rhok0sintheta, and rhok0costheta are outputted assuming the amplitude of a reception pass signal as rho, the phase difference as theta, and a proportional constant as k0. Those signals are multiplied by the in-phase axis reception signal and the orthogonal axis reception signal, and furthermore, they are added in brace fashion, thereby, the influence of the phase difference theta can be eliminated, and data demodulation and timing reproduction can be performed by using the signals.</p> |
