Separate Turbo Code and Single Turbo Code Adaptive OFDM Transmissions

Separate Turbo Code and Single Turbo Code Adaptive OFDM Transmissions

This paper discusses the application of adaptive modulation and adaptive rate turbo coding to orthogonal frequency-division multiplexing (OFDM), to increase throughput on the time and frequency selective channel. The adaptive turbo code scheme is based on a subband adaptive method, and compares two adaptive systems: a conventional approach where a separate turbo code is used for each subband, a...

A Turbo Code Tutorial

| We give a tutorial exposition of turbo codes and the associated algorithms. Included are a simple derivation for the performance of turbo codes, and a straightforward presentation of the iterative decoding algorithm. The derivations of both the performance estimate and the modi ̄ed BCJR decoding algorithm are novel. The treatment is intended to be a launching point for further study in the ̄el...

Punctured Turbo Code Ensembles

We analyze the asymptotic performance of punctured turbo codes. The analysis is based on the union bound on the word error probability of maximum likelihood decoding for a punctured turbo code ensembles averaged over all possible puncturing patterns and interleavers. By using special probabilistic puncturing, we prove that, for a given mother turbo code ensemble [C] with a finite noise threshol...

Adaptive Turbo Coded OFDM

data transmission which requires robust and spectrally efficient communication techniques. The basic idea behind adaptive transmission is to improve spectral efficiency by varying the transmission power level, symbol transmission rate, constellation size, and coding rate scheme. In this paper adaptive modulation and turbo coding is applied to OFDM that can provide a lower bit error rate than ad...

Turbo Demodulation of Zero-Padded OFDM Transmissions