BER performance of MLSE demodulator for digital SSB with partial response signaling

In this paper, we propose a demodulation method using maximum likelihood sequence estimation (MLSE) after coherent detection for partial response signaling single sideband (SSB) signals and present the bit error rate performance achieved by this configuration. Coherent detection is implemented by a pilot carrier method. The power of the pilot carrier inserted in the SSB modulated wave and the noise bandwidth of the phase locked loop (PLL) that extracts the base carrier cause the degradation in the power efficiency of the SSB signal. We then evaluate the equivalent carrier-to-noise power ratio (CNR) degradation of the pilot carrier method. The partial response demodulated signal can be MLSE decoded since the signal is time correlated. From the characteristics of an SSB demodulated signal, first-order MLSE decoding using only the in-phase channel generally results. Here, we also study a complex MLSE decoding method that considers the quadrature channel. Based on this configuration, we show that the SSB signal power efficiency was improved by about 5 dB compared to the conventional coherent detection and instantaneous identification and demodulation method. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(4): 44–53, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20167