Effects of Channel Estimation on Multiuser Virtual MIMO-OFDMA Relay-Based Networks
Jiménez, V. P. G.
; Armada, A. G.
Eurasip Journal on Wireless Communications and Networking Vol. 2010, Nº 1, pp. 1 - 13, November, 2010.
ISSN (print): 1687-1499
ISSN (online): 1687-1472
Journal Impact Factor: 0,805 (in 2013)
Digital Object Identifier: 10.1155/2010/764784
A practical multiuser cooperative transmission scheme denoted as Virtual Maximum Ratio Transmission (VMRT) for multiple-input multiple-output-orthogonal frequency division multiple access (MIMO-OFDMA) relay-based networks is proposed and evaluated in the presence of a realistic channel estimation algorithm and using low-density parity-check (LDPC) codes. It is shown that this scheme is robust against channel estimation errors. It offers diversity and array gain, keeping the complexity low with a multiuser and multiantenna channel estimation algorithm that is simple and efficient. In addition, the combination with LDPC codes provides improved gains; diversity gains larger than 6 dB can be easily obtained with a reduced number of relays. Thus, this scheme can be used to extend coverage or increase system throughput by using simple cooperative OFDMA-based relays.