Vandermonde frequency division multiplexing

We consider a cognitive radio scenario where a primary and a secondary user wish to communicate with their corre-sponding receivers simultaneously over frequency selective channels. Under realistic assumptions that the secondary transmitter has no side information about the primary’s mes-sage and each transmitter knows only its local channels, we propose a Vandermonde precoder that cancels the in-terference from the secondary user by exploiting the redun-dancy of a cyclic prefix. Our numerical examples show that VFDM, with an appropriate design of the input covariance, enables the secondary user to achieve a considerable rate while generating zero interference to the primary user. 1