Turbo coding is the most commonly used error correcting scheme in wireless systems resulting in maximum coding gain. In this paper, a comparative study of the symbol-bysymbol maximum a posteriori (MAP) algorithm, its logarithmic versions, namely, Log-MAP and Max-Log-MAP decoding algorithms used in SISO Turbo Decoders are analyzed. The performance of Turbo coding algorithms are carried out in te...

A decision-feedback maximum a posteriori (MAP) receiver is proposed for code-division multiple-access channels with time-selective fading. The receiver consists of a sequence-matched filter and a MAP demodulator. Output samples (more than one per symbol) from the matched filter are fed into the MAP demodulator. The MAP demodulator exploits the channel memory by delaying the decision and using a...

For estimating the states or outputs of a Markov process, the symbol-by-symbol maximum a posteriori (MAP) algorithm is optimal. However, this algorithm, even in its recursive form, poses technical diiculties because of numerical representation problems, the necessity of non-linear functions and a high number of additions and multiplications. MAP like algorithms operating in the logarithmic doma...

where x(z) = ∑∞ j=1 xjz j is the symbol of the operator. In terms of the Hardy polarization of odd spinors on S, B1(x) = P+MxP−, where P+, P− are projections and Mx is the multiplication operator corresponding to x. The map x 7−→ B1(x) is conformally equivariant in a sense explained in §2. In this paper we derive explicit expressions for certain well-known higher-order generalizations of this m...

We show that, for a certain class of systems, the problem of establishing the existence of periodic orbits can be successfully studied by means of a symbolic dynamics approach combined with interval methods. Symbolic dynamics is used to find approximate positions of periodic points, and the existence of periodic orbits in a neighborhood of these approximations is proved using an interval operat...

We address the question of whether Thom-Boardman symbol a map germ is an invariant with respect to bi-Lipschitz right equivalence. give counterexample showing that in general answer negative. prove rank contact invariant. Consequently, first and its length are invariants.

Stochastic Bayesian detection has recently emerged as a competitive receiver design paradigm for wireless communications applications. It uses Monte Carlo simulations to perform Bayesian inference of a probabilistically modeled communication system so as to obtain the maximum a posterior (MAP) symbol detection and/or channel estimation results. The Monte Carlo concept is attractive in that it i...

In this letter, coherent detection of π 4 -DE-QPSK is considered, but our analysis also holds for common DEQPSK. It is shown that maximum a-posteriori (MAP) sequence detection can be regarded as an approximation, based on selecting dominant exponentials, of MAP symbol detection. A better approximation, relying on piecewise-linear fitting of the logarithm of the hyperbolic cosine, is proposed. T...

In this paper the expectation-maximization (EM) algorithm for maximum a posteriori (MAP) estimation of a random vector is applied to the problem of symbol detection for CPM signals transmitted over timeselective Ftayleigh fading channels. This results in a soft-in soft-out (SISO) detection algorithm suitable for iterative detection/decoding schemes. Simulation results show that the error perfor...

The problem of simultaneously estimating phase and decod-ing data symbols from baseband data is posed. The phase sequence isassumed to be a random sequence on the circle, and the symbols areassumed to be equally likely symbols transmitted over a perfectly equalizedchannel. A dynamic programming algorithm (Viterbi algorithm) is derivedfor decoding a maximum (Iposteriori (...