DPSK Sistemler için LMS Algoritma ve ML Kriteri Temelli, Gözü Kapalı Kanal Kestiriminin ve Turbo Denkleştirmenin Birlikte Yapılması

Year 2010, Volume: 12 Issue: 2, 75 - 84, 01.12.2010

Serkan Yakut

Abstract

Sayısal haberleşme sistemlerinde, alıcıda gözü kapalı kanal kestirme ve turbo denkleştirme işlemlerinin birlikte yapılması, gözü kapalı turbo denkleştirme olarak adlandırılır. Bu çalışmada, farksal faz kaydırmalı anahtarlama (DPSK) modülasyonu kullanan sayısal haberleşme sistemleri için yeni bir gözü kapalı turbo denkleştirici geliştirilmiştir. DPSK tercih edilmesinin sebebi faz belirsizliğini çözmektir. Haberleşme kanalının katsayılarını kestirmek için LMS algoritma, toplanır beyaz Gauss gürültünün (AWGN) varyansını kestirmek için ise ML kriteri kullanılmıştır

Keywords

yumuşak gözü kapalı kanal kestirimi, turbo denkleştirme, gözü kapalı LMS kestirimci

LMS Algorithm and ML Criterion Based, Combined Blind Channel Identification and Turbo Equalization for DPSK Systems

Abstract

In digital communication systems, combined blind channel identification and turbo equalization at the receiver is called blind turbo equalization. In this study, a new blind turbo equalizer is developed for digital communication systems which are using DPSK modulation. The reason for prefering DPSK is to remove phase ambiguity. Least-Mean Square (LMS) algorithm is used to estimate the channel coefficients and additive white Gaussian noise (AWGN) variance is estimated by using of maximum-likelihood (ML) criterion

Keywords

soft blind channel identification, turbo equalization, blind LMS estimator

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