Thesis (Ph.D.)--City University of Hong Kong, 2009. / "Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves [142]-152)

Thesis (M.S.)--University of Texas at Dallas, 2007. / Includes vita. Includes bibliographical references (leaves 84-85)

No description available.

Due to constraints on spectrum availability and transmitter power, both bandwidth and power efficient communication techniques are desirable for mobile radio. Continuous phase modulated (CPM) signals have gained attention because of their attractive power spectra (Steele, 1992). It has been shown that the trellis coded modulation (TCM) schemes could provide better bit error rate performances compared to the uncoded schemes (Ungerboeck, 1982). Therefore, the combination of TCM which improves error probability and CPM signals which yield low spectral occupancy is expected to provide good coding and modulation over bandwidth and power limited channels such as the one encountered in mobile radio communications.In this research, a Trellis Coded Modulation (TCM) scheme, which combines convolutional coding and partial response Continuous Phase Modulation (CPM) such as Gaussian Minimum Shift Keying (GMSK), is investigated. Also, this study concentrates on the use of rate-half convolutional codes, and GMSK (B(subscript)0T=0.3). The latter has been adopted in the Global System for Mobile Communications (GSM) system.Appropriate codes are selected assuming Maximum Likelihood Sequence Detection (MLSD) based on the Viterbi algorithm using an extensive computer search. The bit-error-rate (BER) performances of the selected trellis coded GMSK schemes are theoretically evaluated in the presence of additive white Gaussian noise (AWGN) and frequency-flat fading. In the case of fading, the analysis is simplified to assume only amplitude-fading, and without considering the effect of fading on the phase of the received signal.Computer simulations are used to evaluate the BER performances of the proposed trellis coded GMSK schemes in the presence of AWGN and practical impairments, such as sample timing offset and carrier phase errors. Coding gains of up to 2.2dB at a BER of 10(subscript)-3 ++ / are obtained under ideal sample timing and carrier recovery conditions. This has been achieved without increasing the receiver complexity based on the number of states in the Viterbi decoder, compared to the uncoded GMSK scheme. Furthermore, these coded schemes are more tolerant to sample timing and carrier phase impairments.Also, the BER performances of the proposed trellis coded GMSK schemes have been extensively investigated by computer simulations for frequency-flat and frequency-selective fading channels. In the case of frequency-selective fading, the Viterbi decoding is made adaptive to cater for the channel impulse response variations with time. With this adaptive receiver, the irreducible BERs of the coded scheme is found to be lower than that of the uncoded. Performance improvements are obtained with a trellis coded GMSK scheme using a constraint length 2 code with a Viterbi decoder of 16 states compared to the 128 states required for the uncoded scheme. Further, the coded scheme has shown less sensitivity to carrier phase errors, compared to the uncoded.

Thesis (M.S.)--Ohio University, November, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 68-70).

Trellis-coded modulation (TCM) is a known technique to increase the data rate without increasing the channel bandwidth when implementing error correction coding. TCM is a combination of M-ary modulation and error correction coding. This thesis investigates the performance of a low spectral efficiency TCM system, which is compared with three alternative systems having comparable bandwidth. The three alternative systems are all non-TCM systems and consist of QPSK with independent r=1/2 error correction coding on the in-phase and quadrature components, 8-ary biorthogonal keying (8-BOK) with r=2/3 error correction coding, and 16-BOK with r=3/4 error correction coding. The effects of both additive white Gaussian noise (AWGN) and pulse-noise interference (PNI) are considered. The TCM system shows much better than expected performance and significant resistance to PNI, and performance improves as the number of memory element increases. The alternative QPSK system with soft decision decoding (SDD) experiences significant degradation with PNI. The 8-BOK with r=2/3 error correction and 16-BOK with r=3/4 error correction systems occupy approximately the same bandwidth as the TCM system and show better performance in PNI than the alternative QPSK system.

Ever since the proposal of turbo code in 1993, there has been extensive research carried out to improve both the performance and spectrum efficiency. One of the methods used to improve the spectrum efficiency was to combine turbo code with a trellis-coded modulation scheme, called turbo trellis-coded modulation (TTCM). The scheme is used in various applications such as deep-space communication, wireless communication and other fields. It is a well established fact that an increase in an interleaver size of a TTCM system results in an improved performance in the bit error rate (BER). In this thesis repeat-punctured turbo trellis-coded modulation (RPTTCM) is proposed. In RPTTCM, the effect of repeat-puncture is investigated on a TTCM system, repetition of the information bits increases the interleaver size, followed by an appropriate puncturing scheme to maintain the respective code rate. The TTCM and RPTTCM systems are simulated in an Additive White Gaussian Noise (AWGN) channel. To understand how the RPTTCM scheme will perform in a wireless channel, the Rayleigh flat fading channel (with channel state information known at the receiver) will be used. The BER performance bound for the TTCM scheme is derived for AWGN and Rayleigh flat fading channels. Thereafter repeat-punctured is introduced into the TTCM system. The BER performance bound is then extended to include repeat-puncturing. The performances of the TTCM and RPTTCM systems are then compared. It was found that the RPTTCM system performed better at high signal-to-noise ratio (SNR) in both AWGN and Rayleigh flat fading channels. The RPTTCM scheme achieved a coding gain of approximately 0.87 dB at a BER of for an AWGN channel and 1.9 dB at a BER of for a Rayleigh flat fading channel, for an information size of N=800. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

No description available.

Thesis (Ph. D.)--Ohio University, November, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 84-85).

Thesis (M.E.)--University of Canterbury, 2008. / Typescript (photocopy). "June 2008." Includes bibliographical references (p. 87-96). Also available via the World Wide Web.