Improved Wideband Precoding With Arbitrary Subcarrier Grouping in MIMO-OFDM Systems
Precoding in the multiple-input multiple-output orthogonal frequency division multiplexing system is investigated. In conventional WideBand Precoding (WBP), only one precoder, obtained from the decomposition of the subcarrier independent channel matrix, is used for all subcarriers. With an investigation of the relationship between the subcarrier independent channel matrix and the temporal/frequency channels, an improved WBP scheme is proposed for practical scenarios in which a part of subcarriers are allocated to a user. The improved WBP scheme is a generalized scheme of which narrow-band precoding and conventional WBP schemes are special modes.