Robust spread spectrum type communication with M-ary quasi orthogonal signaling for wireless fading channels M-ary yaklaşik dikgen sinyalleşme ile yayili spektruma sahip sistemler için etkin telsiz haberleşme

GÜVENSEN G. M., TANIK Y., YILMAZ A. Ö.

2012 20th Signal Processing and Communications Applications Conference, SIU 2012, Fethiye, Mugla, Turkey, 18 - 20 April 2012 identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/siu.2012.6204750
  • City: Fethiye, Mugla
  • Country: Turkey
  • Middle East Technical University Affiliated: Yes

Abstract

In this paper, a receiver architecture with reduced complexity is proposed for spread spectrum type communication with M-ary quasi orthogonal signaling. The proposed structure comprises of the channel and code matched filtering (MF) concatenated with a reduced state maximum likelihood sequence estimation (MLSE) type processing at symbol rate. MLSE, which takes the interference caused by nonideal cross- and autocorrelations of the spreading codes and multi-path channel into account, is directly applied to the unwhitenedmatched filter outputs. The hypothetical matched filter bound (MFB) is achieved by the proposed structure with the use of a reasonable number of states. By using the proposed reduced state Ungerboeck type MLSE based receiver, it is seen that M-ary quasi orthogonal signaling is an effective spread spectrum type modulation technique for multi-path channels with large delay spread at low power. © 2012 IEEE.