Title :
Link adaptation with distributed Jacobi eigenbeamforming for MIMO systems
Author :
Zacarias, E.B. ; Werner, Stefan ; Wichman, Risto
Author_Institution :
Helsinki Univ. of Technol., Helsinki
Abstract :
This work presents a transmission strategy for closed-loop MIMO systems, where compact feedback messages meant for transmit weight adaptation are also used to convey basic link adaptation requests that can improve the link reliability or the data throughput without additional feedback overhead. The proposed link adaptation varies the number of orthogonal transmit beams and the symbol modulation employed on each beam. The simulation study focuses in a system with four transmit and two receive antennas, with constant data rate and two different underlying beamforming schemes: a recently proposed Jacobi beamformer, and a Grassmanian codebook approach. It is shown that both schemes can obtain an improvement of around 1 dB in bit error probability (BEP) performance, in slowly fading and spatially uncorrelated channels, compared to the case where both beams are used all the time. The application of the proposed technique to other precoding algorithms is briefly discussed.
Keywords :
MIMO communication; error statistics; receiving antennas; telecommunication links; transmitting antennas; Grassmanian codebook; beamforming schemes; bit error probability; closed loop MIMO systems; compact feedback messages; constant data rate; distributed Jacobi eigenbeamforming; link adaptation; precoding algorithms; receive antennas; transmission strategy; transmit antennas; transmit weight adaptation; Array signal processing; Fading; Feedback; Jacobian matrices; MIMO; Niobium compounds; Optical modulation; Receiving antennas; Throughput; Transmitters;
Conference_Titel :
Wireless Communication Systems, 2007. ISWCS 2007. 4th International Symposium on
Conference_Location :
Trondheim
Print_ISBN :
978-1-4244-0979-2
Electronic_ISBN :
978-1-4244-0979-2
DOI :
10.1109/ISWCS.2007.4392302