Adaptive transmission mode selection in LTE-A carrier aggregation scenarios

Abstract

Carrier aggregation is one of the most distinct features of 4G systems including LTE-A (Long Term Evolution Advanced), which is being standardized in 3GPP as part of LTE Release 10. The closed-loop concept with codebook based precoding MIMO (multiple-input multiple-output) and transmission mode selection, termed as RI (rank indicator) selection, have been deployed in LTE-A systems to provide high system performance required by 4G systems. This article focuses on the study of adaptive transmission mode selection in LTE-A carrier aggregation scenarios. We propose an adaptive transmission mode selection scheme using average channel capacity and BER to maximize the average spectral efficiency (ASE) with a given target bit error ratio (BER). Numerical results demonstrate improvement over each fixed modern terms of average spectral efficiency.