Coded Orthogonal Signaling
Abstract
In this thesis, a new scheme of encoding orthogonal MFSK signals with convolutional codes is proposed. Instead of separating the code and the signals as is done conventionally, here the m outputs of the convolutional encoder of rate k/m are used to select the M = 2m orthogonal FSK signals. This combined coded system is called trellis-coded modulation MFSK (TCM/MFSK). The free distance of TCM/MFSK codes is found computationally. Asymptotic coding gains (ACG) of several TCM/MFSK systems relative to uncoded MFSK systems having the same bandwidth efficiency (bits/s/Hz) are calculated. Both analytic descriptions and natural mapping implementations of TCM/4-FSK with rate 1/2 and TCM/8-FSK with rate 2/3 for several constraint lengths of the convolutional codes are given. The analytic description of TCM/MFSK is also obtained computationally. Coding, TCM, MFSK.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1992
- Accession Number
- ADA257635
Entities
People
- Salih Semerciler
Organizations
- Naval Postgraduate School