A Weighted Block Adaptive Estimation for STBC Single-Carrier System in Frequency-Selective Time-Varying Channels

다중 경로 시변 채널 환경에서 시공간 블록 부호 단일 반송파 시스템을 위한 가중치 블록 적응형 채널 추정 알고리즘

  • 백종섭 (연세대학교 전기전자공학과 디지털전송 연구실) ;
  • 권혁제 (연세대학교 전기전자공학과 디지털전송 연구실) ;
  • 서종수 (연세대학교 전기전자공학과 디지털전송 연구실)
  • Published : 2007.03.31

Abstract

In this paper, a weighted block adaptive channel estimation (WBA-CE) for a space-time block-coded (STBC) single-carrier transmission with a cyclic-prefix is proposed. In operation of the WBA-CE, a STBC matrix-wise block for filter input symbols is first formulated. Applying a weighted a posteriori error vector-based least-square (LS) criterion for this block, the coefficient correction terms of the WBA-CE are then computed. An approximate steady-state excess mean-square error (EMSE) of the WBA-CE for the stationary optimal coefficient is also analyzed. Simulation results show in a time-varying typical urban (TU) channel that the proposed channel estimator provides better bit-error-rate (BER) performances than conventional algorithms such as the NLMS and RLS channel estimators.

본 논문에서는 순환 보호 구긴(cyclic-prefix)을 사용하는 시공간 블록 부호 (STBC: Space-Time Block-Coding) 단일 반송파 시스템에서 향상된 채널 성능을 위한 가중된 블록 적응형 주파수 영역 채널 추정기를 제안한다. 제안된 채널 추정기 구조는 필터 입력 신호에 대해 STBC로 구성된 블록을 형성하며, 이후 형성된 입력 블록에 대해 사후 오차 (a posteriori error)를 이용하는 가중된 LS (least-square) 규준을 적용하여 알고리즘을 유도한다. 또한 정적 채널에서 steady-state EMSE (excess mean-square error) 분석을 통해 블록 길이가 늘어남에 따라 EMSE를 분석한다. 전산 모의실험에서는 시변 TU (typical urban) 채널에서 블록 길이를 증가시킬수록 제안한 채널 추정기는 기존 NLMS와 RLS 채널 추정기들 보다 우수한 성능을 나타냄을 확인 할 수 있다.

Keywords

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