A Study on Baseband Signal Processings in On-Board Processing Satellite Systems

点击翻译按钮获取中文摘要

This work was carried out in order to develop baseband signal processing methods and new functions in on-board processing satellite systems. The summary of the obtained results are shown as follows.1. Maximum likelihood decoding with interference canceling The signal processing of MSE and Viterbi decoding was introduced on board the satellite. The error rate was dervied to demonstrate the performance improvements of the processing. We noted that the improvements became large as the interference level.2. Inter-Satellite optical communications(1) In a inter-satellite optical communications, the dominant factor of performance degradation comes from the background optical noise from the sun. It is inevitable to use the coding technique to combat the factor. We derived the error rate of OOK systems using convolutional coding / soft decision Viterbi decoding, and showed the significant coding gain.(2) For the purpose of suppressing the timing jitter effects due to the satellite motions, we used the optical PPM and separate coding. Three different receiver structures were proposed. Form the analytical results, we noted that, the receiver of soft decision - sum was best of three and suppressed the timing jitter effects.(3) The combined PPM and convolutional coding scheme was introduced to overcome the effects of pulse stretching due to the earth-satellite optical communications. The numerical results of the error rate showed that, the scheme was very effective for the pulse stretching.