On the physical layer performance with rank indicator selection in LTE/LTE-Advanced system

A centralized inter-cell rank coordination mechanism for 5G systems

“…The other parameters, namely the ranks d l and the interference prices α lk ) of the interfering users are obtained from information readily available at the central node. This is in contrast to the complete channel matrix information required for an ICM based rank adaptation approach, such as those presented in [2], [3].…”

“…Several open-loop and closed-loop rank coordination algorithms for the long term evaluation (LTE) and LTEAdvanced (LTE-A) systems are presented and numerically evaluated in [3]. Alternatively, reference [2] proposes a method to select the rank that maximizes the mutual information given a target Block Error Ratio under the assumption of having perfect channel state information (CSI) and no inter-cell interference.…”

“…Alternatively, reference [2] proposes a method to select the rank that maximizes the mutual information given a target Block Error Ratio under the assumption of having perfect channel state information (CSI) and no inter-cell interference. The algorithms presented in [2], [3] are based on the signal-to-interference-plus-noise ratio (SINR), which requires knowledge of the interference covariance matrix (ICM). Due to the multitudes of matrix operations involved, estimating the SINR from the ICM requires accurate CSI, and is computationally costly [4].…”

On the Evolution of Coordinated Multi-Point (CoMP) Transmission in LTE-Advanced

“…Moreover, RI indicates the MIMO ranking i.e. the number of data streams to be transmitted in parallel for the next transmission over the MIMO channel [19]. These parameters are transmitted in a quantized manner to BS so as to reduce signaling overhead.…”

Implementation of the precoder matrix indicator selection using MMSE trace criterion for the downlink transmission in LTE

“…Practical criteria for determining RI and PMI in LTE include [11][12][13][14][15] minimum mean square error (MMSE) geometric mean, MMSE trace, maximum post processing SNR, post MMSE, maximum channel capacity, and maximum mutual information. Note that most of these criteria are related to the MMSE detector and rely on the computation of the error covariance matrix.…”