多重調變係數CPFSK之相差解調

Differential Detection of Multi-h CPFSK

楊新雄(Richard Hsin-Hsyong Yang) ； 羅子喚(Zi-Huan Luo) ； 陳俊達(Jun-Da Chen)

《大葉學報》 9卷2期 (2000/12) Pp. 93-98

https://doi.org/10.7119/JDYU.200012.0093

摘要

在本論文中，我們針對multi-h CPFSK的one-bit相差解調來進行研究。過去在AWGN通道背景下，一般大都考慮以最大相似序列檢測器（MLSD）[2]來解調多重調變係數（multi-h）CPFSK信號。但由於同調技術在無線通訊的環境下，接收機不易實現，所以本論文利用相差的技術來解調multi-h CPFSK信號。我們針對multi-h CPFSK具有週期性調變係數（週期為二）的特性，以解析方法推導出one-bit相差解調之系統誤碼率，並經過模擬後驗證了此方法的準確性。研究發現對multi-h信號以one-bit相差檢測來進行解調是可以實現的，並且有不錯的性能表現；另外，模擬結果顯示對於multi-h CPFSK在傳統解調方法中有較佳性能的編碼組合（即歐氏距離大者），其在相差解調系統中，性能未必優於歐氏距離較小的編碼組合。

關鍵字

one-bit相差解調 ； 多重調變係數CPFSK ； 誤碼率 ； 最大相似序列檢測

並列摘要

In this paper we focus on the one-bit differential detection of multi-h continuous phase frequency shift keying (CPFSK). Previous research has considered maximum likelihood sequence detectors (MLSD) to demodulate multi-h CPFSK in an AWGN background [2]. Since the implementation of the coherent technology is difficult in a wireless environment, a differential technique is applied to demodulate the multi-h signals. Analytical results for bit-error performance are investigated for various multi-h modulations, based upon the fact that the modulation indexes (two periods) are applied periodically. The accuracy of the analytical results is verified with computer simulations.It is found that a multi-h CPFSK signal indeed can be demodulated through differential detection, the performance is good. It is also interesting to note that a set of modulation indexes with a larger minimum-squared Euclidean distance does not always outperform a set with a smaller distance.

並列關鍵字

one-bit differential detection ； multi-h CPFSK ； bit-error rate ； maximum-likelihood sequence detector