Reducing Hardware Complexity of MIMO Systems with Antenna Subarray Formation

Antenna subarray formation (ASF) is an alternative to antenna selection technique that reduces the hardware complexity of MIMO systems with a minor performance penalty with respect to the full-complexity system. With this method, each RF chain is not allocated to a single antenna element, but to a complex-weighted and combined response of a subarray of the available antenna elements. In this paper we compare the capacity performance of several analytical algorithms for receive ASF and present theoretical upper bounds on the ergodic capacity of the proposed technique for Rayleigh i.i.d. channels.