Abstract

In this paper we study diversity combining for turbo-coded frequency hopped spread-spectrum (FH/SS) communication systems in the presence of fading and partial band interference. For a fixed channel to information bit rate we compare different diversity order and code rate combinations for coherent binary phase shift keying (CBPSK) and non-coherent binary frequency shift keying (NCBFSK). We find that it is always better to use a low-rate code and no repetition for both CBPSK and NCBFSK. We apply a well-known approximation to the LLR for NCBFSK and find that it results in very similar performance to the exact LLR. We also propose a simple method for signal-to-noise ratio (SNR) estimation in NCBFSK without training symbols that offers performance near that of the case of exact knowledge of the SNR even for small hop sizes. In the case of CBPSK we propose an iterative method for estimating the SNR, also without training symbols, that offers performance near that of the case of perfect knowledge of the SNR when there is no interference, but otherwise requires large hop sizes to accurately estimate the SNR.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.