Symbol synchronization for MSK signals based on matched filtering

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2003

Öğrenci: SERDAR SEZGİNER

Danışman: YALÇIN TANIK

Özet:

In this thesis, symbol timing recovery in MSK signals is investigated making use of matched filtering. A decision-directed symbol synchronizer cascaded with an MLSE receiver is proposed for fine timing. Correlation (matched filter) method is used to recover the timing epoch from the tentative decisions obtained from the Viterbi algorithm. The fractional delays are acquired using interpolation and an iterative maximum search process. In order to investigate the tracking performance of the proposed symbol synchronizer, a study is carried out on three possible optimum timing phase criteria: (i) Mazo criterion, (ii) the minimum squared ISI criterion (msISI), and (iii) the minimum BER criterion. Moreover, a discussion is given about the timing sensitivity of the MLSE receiver. The performance of the symbol synchronizer is assessed by computer simulations. It is observed that the proposed synchronizer tracks the variations of the channels almost the same as the msISI criterion. The proposed method eliminates the cycle slips very succesfully and is robust to frequency-selective multipath fading channel conditions even in moderate signal-to-noise ratios.