电子设计工程
電子設計工程
전자설계공정
ELECTRONIC DESIGN ENGINEERING
2015年
2期
151-154,159
,共5页
帧同步%相关%FPGA%卫星通信接收机
幀同步%相關%FPGA%衛星通信接收機
정동보%상관%FPGA%위성통신접수궤
frame synchronization%correlation%FPGA%satellite communication receiver
帧同步算法通过检测帧头信息，使接收机从接收数据流中提取帧起始时刻和初始频偏，以引导解调环路恢复出有效数据。本文首先简要介绍了基于相关的经典帧同步算法原理，然后分析了信道环境对相关性能的影响，最后详细描述了一种经过改进的精确帧同步算法及其FPGA实现结果。该算法综合采用了分段本地相关、分段延迟相关和动态检测门限，有效解决了在大频偏和强噪声环境下的捕获虚（漏）警问题，并通过过采样和平滑提高了帧起始时刻与初始频偏的捕获精度，使解调环路锁定更快。测试表明，该算法复杂度适中，在低信噪比、高频偏环境下也具有优异性能，适合应用于卫星通信接收机。
幀同步算法通過檢測幀頭信息，使接收機從接收數據流中提取幀起始時刻和初始頻偏，以引導解調環路恢複齣有效數據。本文首先簡要介紹瞭基于相關的經典幀同步算法原理，然後分析瞭信道環境對相關性能的影響，最後詳細描述瞭一種經過改進的精確幀同步算法及其FPGA實現結果。該算法綜閤採用瞭分段本地相關、分段延遲相關和動態檢測門限，有效解決瞭在大頻偏和彊譟聲環境下的捕穫虛（漏）警問題，併通過過採樣和平滑提高瞭幀起始時刻與初始頻偏的捕穫精度，使解調環路鎖定更快。測試錶明，該算法複雜度適中，在低信譟比、高頻偏環境下也具有優異性能，適閤應用于衛星通信接收機。
정동보산법통과검측정두신식，사접수궤종접수수거류중제취정기시시각화초시빈편，이인도해조배로회복출유효수거。본문수선간요개소료기우상관적경전정동보산법원리，연후분석료신도배경대상관성능적영향，최후상세묘술료일충경과개진적정학정동보산법급기FPGA실현결과。해산법종합채용료분단본지상관、분단연지상관화동태검측문한，유효해결료재대빈편화강조성배경하적포획허（루）경문제，병통과과채양화평활제고료정기시시각여초시빈편적포획정도，사해조배로쇄정경쾌。측시표명，해산법복잡도괄중，재저신조비、고빈편배경하야구유우이성능，괄합응용우위성통신접수궤。
By detecting frame header information, a frame synchronization algorithm is able to extract the start time of frame header and the initial frequency offset from received datas, these information will lead the demodulation loops to recover valid data. In this paper, We first introduced the principle of correlation-based classic frame synchronization algorithms briefly, then analysed the impact of channel environment on the performance of correlation, finally described an improved precise frame synchronization algorithm in detail, as well as its implementation based on FPGA . By using segmental local/delay correlation and dynamic detection threshold, the algorithm solves the problem of false-alarm and false-dismissal in the circumstance of strong noise and large frequency offset, and also improves the capture accuracy of frame header start time and calculated initial frequency offset through over sampling and smoothness, which makes demodulation loops lock faster. Tests show that, the algorithm is characterized with moderate complexity and favourable performance, even in the low signal-to-noise ratio and high frequency offset conditions, it is applicable to the satellite communication receiver.
