Effects of cochannel interference on MSK and OQPSK signals in satellite channels

Philip, Varghese (1984) Effects of cochannel interference on MSK and OQPSK signals in satellite channels. Masters thesis, Memorial University of Newfoundland.

[English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (17MB) [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

Abstract

The implementation of frequency-reuse techniques and sharing of the same frequency band with terrestrial microwave networks have increased the levels of cochannel interference in satellite communication systems. In fact, in certain situations such an interference can become the dominant factor in limiting the system performance. In this thesis, we analyze the effect of cochannel interference on the error rate performance of MSK and OQPSK signals transmitted through a satellite channel. -- The satellite channel is assumed to exhibit both amplitude and phase nonlinearities. The system model assumed a sufficiently large bandwidth so that the intersymbol interference may be neglected. Narrowband Gaussian noise is assumed on both links but the cochannel interference is considered only in the uplink. -- The bit error rate expressions are derived for MSK and OQPSK signaling techniques in the form of infinite series containing double integrals. The effect of multiple cochannel interference is evaluated using these expressions. A simple expression which does not contain infinite series is also derive for evaluation the bit error rate when only one cochannel interferer is present. The effect of the TWT input power backoff on the bit error rate is also analyzed. The error rate expressions are evaluated over a range of uplink and downlink signal to noise ratios. -- The following conclusions are drawn from this study: -- (a) MSK is superior to OQPSK for all uplink and downlink signal to noise ratios for hard-limited and TWT channels. -- (b) The optimum operating region is the saturation region for both signaling schemes. -- (c) The hard-limited model is a good replacement for the TWT model for low uplink SNR for both the signaling techniques.

Actions (login required)

View Item