Title :
Improved Pilot-Aided Channel Estimation in Zero Padded MC-CDMA Systems
Author :
Cardoso, Deolinda Fontes ; Backx, Fabian David ; Sampaio-Neto, Raimundo
Author_Institution :
Center of Naval Syst. Anal. (CASNAV), Rio de Janeiro
Abstract :
This paper considers two simple procedures to improve the channel frequency response estimate for uplink zero padded MC-CDMA systems. The first approach uses a precomputed matrix that projects the original discrete frequency response onto the subspace where the true frequency response lies. The second uses a constrained MMSE optimization that forces the estimate to belong to this subspace. Analytical expressions for the mean square error and its upper and lower bounds are presented for the conventional and the two improved channel estimators. Numerical results show significant reduction in both the multiple access interference and the noise terms of the estimation error when using the improved estimators. Simulation results indicate that MMSE receivers using each of the improved procedures achieve gain in bit error rate performance.
Keywords :
channel estimation; code division multiple access; frequency estimation; frequency response; least mean squares methods; matrix algebra; optimisation; constrained MMSE optimization; mean square error; pilot-aided discrete channel frequency response estimation; precomputed matrix; uplink zero padded MC-CDMA system; Channel estimation; Constraint optimization; Frequency estimation; Frequency response; Interference constraints; Mean square error methods; Multicarrier code division multiple access; Multiple access interference; Noise reduction; Subspace constraints; Channel Estimation; MC-CDMA; Pilot-aided;
Conference_Titel :
Wireless Pervasive Computing, 2009. ISWPC 2009. 4th International Symposium on
Conference_Location :
Melbourne, VIC
Print_ISBN :
978-1-4244-2965-3
Electronic_ISBN :
978-1-4244-2966-0
DOI :
10.1109/ISWPC.2009.4800586
