Rate 1/2 systematic recursive convolutional codes over integer rings modulo-q are investigated for their performance. The investigation examines the performance in severe fading and additive white Gaussian noise for codes with various constraint lengths. The arithmetic for the codes is modulo-q. where the value of q is within the range of 2 to 16. An exhaustive search is carried out for codes with short constraint lengths. A reduced search is developed for larger constraint lengths which restricts the tap polynomials to irreducible polynomials over Zq. The irreducible polynomials are generated and the ones not found in the literature are presented in tables. The search algorithms are outlined and the results for the codes are tabulated.
The performance of selected codes are verified by Monte-Carlo simulation techniques. Several codes have better performance than comparable codes presented in the literature for the Rayleigh fading channel. In sme of cases, the codes found have better performance on the AWGN channel than the best known ring codes.
The characteristics of rotationally invariant (RI) ring codes presented in the literature are used in an exhaustive search for codes over Zq which are invariant to phase shifts of 2[pi]/q. Tables of RI codes optimized for the Rayleigh fading channel are presented along with codes which are optimized for the AWGN channel. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/8099 |
| Date | 11 May 2017 |
| Creators | Kerr, Ronald W. |
| Contributors | Bhargava, Vijay K. |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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