Transmit Precoding for the Multiple Antenna Broadcast Channel

— In this paper we compare the following two methods of transmit precoding for the multiple antenna broadcast channel: vector perturbation applied to channel inversion (also termed zero forcing or ZF) precoding and scalar Tomlinson-Harashima (TH) precoding applied to sum-rate achieving transmit precoding. Our results indicate that vector perturbation applied to channel inversion precoding can significantly reduce power enhancement and yields the full diversity afforded by the channel to each user. Scalar TH-modulo reduction significantly reduces the power enhancement for precoding based on sum-rate criterion. The solution to vector perturbation applied to ZF precoding requires the solution to an integer optimization problem which is exponentially complex, or an approximation to the integer optimization problem which requires the Lenstra-Lenstra-Lovasz algorithm of polynomial complexity. Instead we propose a simpler solution (an approximation) to the vector perturbation problem base...

• Type: Conference
• Year: 2006
• Where: VTC
• Authors: Manish Airy, Sandeep Bhadra, Robert W. Heath Jr., Sanjay Shakkottai
• Keywords: Integer Optimization Problem, Vector Perturbation, Vector Perturbation Problem, VTC 2006