Title :
Pilot allocation by Genetic Algorithms for sparse channel estimation in OFDM systems
Author :
Najjar, Lotfollah
Author_Institution :
Lab. COSIM, Ecole Super. des Commun. de Tunis, Ariana, Tunisia
Abstract :
The comb-type pilot-aided channel estimation in OFDM systems is here considered. The number of pilot subcarriers is generally tuned to tradeoff between performance and spectral efficiency. For time domain sparse channels, the application of the recent theory of Compressed Sensing has proved its efficiency to both ameliorate the estimation accuracy and reduce the transmitted overhead. The performance and uniqueness guarantees remain however closely related to the pilots placement, which are optimized prior to transmission. Few works have addressed the pilot allocation issues. To avoid the computationally prohibitive exhaustive search over all possible allocations, they proposed sub-optimal solutions. This contribution proposes an enhanced pilot design scheme based on Genetic Algorithms. First, we set the adopted problem formulation in the frame of Genetic Algorithms. Then, we propose two algorithms, tailored for the decomposition matrix coherence minimization. Simulation results prove the proposed schemes effectiveness and performance enhancement compared to former pilot design schemes.
Keywords :
OFDM modulation; channel estimation; compressed sensing; genetic algorithms; matrix decomposition; minimisation; OFDM systems; adopted problem formulation; comb type pilot aided channel estimation; compressed sensing; decomposition matrix coherence minimization; genetic algorithms; pilot allocation; sparse channel estimation; time domain sparse channels; Biological cells; Channel estimation; Coherence; Discrete Fourier transforms; Genetic algorithms; Resource management; Sensors; Coherence measure; Compressed Sensing; Genetic Algorithms; OFDM Systems; Pilot Allocation; Sparse channel estimation;
Conference_Titel :
Signal Processing Conference (EUSIPCO), 2013 Proceedings of the 21st European
Conference_Location :
Marrakech