Digital Beam Forming Using Orthogonal Frequency Division Multiplexing in Wireless communication Systems:A Review

Abstract

  Transmit beam forming with receive combining may be a simple technique for exploiting the numerous diversity provided by multiple-input multiple-output (MIMO) systems, and therefore the use of orthogonal frequency division multiplexing (OFDM) allows low quality implementation of this theme over frequency selective MIMO channels. This paper proposes a beam forming technique that reduces feedback necessities for optimum beam forming. Within the projected design, the receiver send back quantized versions of choose beam forming vectors and the transmitter reconstructs the missing beam forming vectors through interpolation. Since a beam forming vector is part invariant and has unit norm, a replacement spherical linear interpolator is proposed that exploits extra parameters for part rotation. These parameters square measure determined at the receiver within the sense of maximizing the minimum channel gain or capability, and sent back to the transmitter alongside the quantized beam forming vectors. Simulation results show that the projected beam forming method needs abundant less feedback data than optimum beam forming with solely slight diversity loss.