V-BLAST type MIMO schemes for UTRA LTE

OFDM (orthogonal frequency division multiplexing) with MIMO (multiple-input multiple-output) scheme, called MIMO-OFDM, has been viewed as a viable means to achieve high user information rates and was deployed in the downlink of the UTRA LTE (UMTS Terrestrial Radio Access Long Term Evolution). The potential maximization of transmitted data rates shall be strived for by spatial multiplexing. In particular, high data rates in the downlink have been considered desirable. Also, in view of an efficient implementation, the downlink requires a thorough assessment. Therefore, the authors will thoroughly consider the theoretical performance of data detection techniques for spatial multiplexing in the UTRA LTE downlink in this communication. Setting out from a discrete-time system model, a generalized model for the evaluation of the signal-to-noise ratio (SNR) at the data detector output will be introduced and applied to the performance evaluation of both linear as well as V-BLAST (Vertical Bell Labs Layered Space Time) data detection techniques. Furthermore their performance will be compared with theoretical bounds of the matched filter and the maximum-likelihood (ML) receivers. It will show that the performance of successive interference cancellation (SIC) based data detection techniques for MIMO-OFDM is beneficial.