Doubly Iterative Decoding of Space-time Turbo Codes Using Log-app Algorithm
نویسندگان
چکیده
In this paper are examined the performances of a low complexity doubly iterative decoder for space-time turbo codes on a quasi-static fading channel, using a Log-APP (logarithmic a posteriori probability) compared to a Max-Log-APP (maximum LogAPP) algorithm decoding algorithm for turbo codes. The decoder uses preliminary soft values of the coded symbols, obtained after a limited number of turbo iterations, in order to reduce the spatial interference of the received signal. In the coding scheme, the core of the iterative decoding structure is a soft-input soft-output APP module. The obtained frame error rate (FER) and bit error rate (BER) performances are compared to those achieved by applying a simple scaling coefficient to the extrinsic information, when a Max-Log-APP algorithm is used.
منابع مشابه
About Symmetric Convolutional Codes of Memory Two and Three Used in Space-time Turbo Coding
In this paper are analysed the performances of different symmetric convolutional turbo codes for a transmission system that uses a doubly iterative decoding algorithm, with multiple antenna diversity. The turbo encoder uses an '–QPP (Quadratic–Permutation–Polynomial) interleaver, and two different decoding algorithms, namely, the Max–Log–APP (Maximum– Logarithm–A–Posteriori–Probability) algori...
متن کاملSequential Decoding for Mobile Receivers
Currently many classical detection and decoding algorithms receive new attention in mobile communications. Amongst those classics are low density parity check codes [1], concatenated codes [2], weighted decoding with log-likelihood values as well as soft-in/soft-out decoding as performed by the BCJR algorithm and its derivatives [4], [5]. All four classics show up as key elements in the so-call...
متن کاملThe Decision Reliability of MAP, Log-MAP, Max-Log-MAP and SOVA Algorithms for Turbo Codes
In this paper, we study the reliability of decisions of e Codes, Channel Reliability, e N comm llular, satellite and we also consider two improved versions, named Log-MAP two different or identical Recursi s, connected in p Fig. 1. The turbo encoder with rate 1/3. The first encoder operat ed b e u, i ond encoder p Lucian Andrei Perişoară, and Rodica Stoian th MAP, Log-MAP, Max-Log-MAP and SOVA ...
متن کاملTurbo Codes with Non-Systematic Constituent Codes∗
Turbo codes are usually constructed using systematic recursive convolutional codes (SRCC’s) as constituent codes. In this paper, we introduce a new class of turbo codes that uses nonsystematic recursive convolutional codes (NSRCC’s) as constituent codes. A systematic constituent code then becomes a particular case of this more general class. The use of this larger class of constituent codes enh...
متن کاملPerformance of Reed - Solomon Block Turbo Code
11, we present two methods for the constuction codes and in section 111, we describe the soft decoding algorithm and give some results of RS soft decoding. In section IV, we give the soft decision algorithm derived from the theoretical Log-Likelihood-Ratio and in section V we describe the iterative algorithm for decoding RS product codes. Section VI and VI1 are dedicated to simulation results o...
متن کامل