Improving on time-reversal with MISO precoding


Robert C. Daniels and Robert W. Heath, Jr.


Proceedings of the Eighth International Symposium on Wireless Personal Multimedia Communications Conference, Aalborg, Denmark, September 18-22, 2005.


Time reversal precoding focuses on a specific receiver by matched filtering with the channel. Unfortunately it also results in temporal sidelobes that must be equalized at the receiver. In this paper we consider multiple-input-single-output (MISO) precoding as a means to avoid temporal sidelobes. We formulate and solve an optimization problem that either forces the sidelobe energy to be zero or maximizes the desired received signal energy to sidelobe energy ratio. This choice depends explicitly on the system parameters. Using this optimized precoding scheme in numerical simulations we demonstrate improved temporal and spatial focusing performance.