Bayat, OguzOdabasioglu, NiyaziOsman, OnurUcan, Osman N.Salehi, MasoudShafai, Bahram2024-03-132024-03-1320081687-14721687-1499https://doi.org/10.1155/2008/458785https://hdl.handle.net/20.500.12662/3698A novel type of turbo coded modulation scheme, called multilevel turbo coded-continuous phase frequency shift keying (MLTC-CPFSK), is designed to improve the overall bit error rate (BER) and bandwidth efficiency. Then, this scheme is combined with a new double decision feedback equalizer (DDFE) to remove the interference and to enhance BER performance for the intersymbol interference (ISI) channels. The entire communication scheme is called multilevel turbo equalization-continuous phase frequency shift keying (MLTEQ-CPFSK). In these schemes, parallel input data sequences are encoded using the multilevel scheme and mapped to CPFSK signals to obtain a powerful code with phase continuity over the air. The performances of both MLTC-CPFSK and MLTEQ-CPFSK systems were simulated over nonfrequency and frequency-selective channels, respectively. The superiority of the two level turbo codes with 4CPFSK modulation is shown against the trellis-coded 4CPFSK, multilevel convolutional coded 4CPFSK, and TTCM schemes. Finally, the bit error rate curve of MLTEQ-CPFSK system over Proakis B channel is depicted and ISI cancellation performance of DDFE equalizer is shown against linear and decision feedback equalizers Copyright (C) 2008 Oguz Bayat et al.eninfo:eu-repo/semantics/openAccessArticle10.1155/2008/4587852-s2.0-62649153779Q1WOS:000264961200001Q2