A Method of Signaling Precoder Information for Dynamical Spectrum Shaping

In this paper, we propose a method for signalling precoder information in cognitive radio networks employing precoded OFDM. In this way, radio transmitters in said cognitive radio networks change their spectral occupancy from one time to another, characterized by the steps of 1. The network determines a suitable precoder uniquely characterized by a codebook index from a finite codebook of precoders, said codebook being known at both the network-side and by the mobile units. 2. The network informs the relevant mobile units about the precoder to use by broadcasting the codebook index Meanwhile, we propose several measurement based optimization methods for spectrum shaping to determine the suitable precoder from, for instance, a database of interference information, or feedback information from UEs about their current interference and noise environment, then notify the precoder information over a CPC. We could use a codebook of precoders each being designed for a certain radio scenario, this precoder jointly considering noise level and frequency band. We could use a codebook with precoders forcing the OFDM signal to be N-continuous and where said codebook index is directly related to the continuity order N. We also could use a codebook with precoders forcing the spectrum of the OFDM signal to be zero at pre-defined frequencies f₀...f_M, and where said codebook index is directly related to the said frequencies. f₀...f_M.