2 research outputs found
Low-Complexity Variable Forgetting Factor Constrained Constant Modulus RLS Algorithm for Adaptive Beamforming
In this paper, a recursive least squares (RLS) based blind adaptive
beamforming algorithm that features a new variable forgetting factor (VFF)
mechanism is presented. The beamformer is designed according to the constrained
constant modulus (CCM) criterion, and the proposed adaptive algorithm operates
in the generalized sidelobe canceler (GSC) structure. A detailed study of its
operating properties is carried out, including a convexity analysis and a mean
squared error (MSE) analysis of its steady-state behavior. The results of
numerical experiments demonstrate that the proposed VFF mechanism achieves a
superior learning and tracking performance compared to other VFF mechanisms.Comment: 10 pages, 4 figures, Elsevier Signal Processing, 201
Iterative Detection and Decoding Algorithms using LDPC Codes for MIMO Systems in Block-Fading Channels
We propose iterative detection and decoding (IDD) algorithms with Low-Density
Parity-Check (LDPC) codes for Multiple Input Multiple Output (MIMO) systems
operating in block-fading and fast Rayleigh fading channels. Soft-input
soft-output minimum mean-square error receivers with successive interference
cancellation are considered. In particular, we devise a novel strategy to
improve the bit error rate (BER) performance of IDD schemes, which takes into
account the soft \textit{a posteriori} output of the decoder in a block-fading
channel when Root-Check LDPC codes are used. A MIMO IDD receiver with soft
information processing that exploits the code structure and the behavior of the
log likelihood ratios is also developed. Moreover, we present a scheduling
algorithm for decoding LDPC codes in block-fading channels. Simulations show
that the proposed techniques result in significant gains in terms of BER for
both block-fading and fast-fading channels.Comment: 17 pages, 4 figures, IEEE Transactions on Vehicular Technology, 201