Journal of Communications
Conventional precoded spatial multiplexing Multiple-Input Multiple-Output (MIMO) systems using limited feedback are mainly based on the notion of time invariant channels throughout transmission. Consequencely, the precoding matrix can be found during the training symbols and used over the subsequent data symbols. In this paper, a more practical system where the channel varies from one block of symbols to another is considered. In such scenario, the precoding matrix designed at the receiver based on the previous training symbols becomes outdated, which results in significant system performance degradation.