Vandermonde Frequency Division Multiplexing for Cognitive Radio

TL;DR

This paper introduces Vandermonde Frequency Division Multiplexing (VFDM), a novel precoding technique for cognitive radio that allows secondary users to communicate without interfering with primary users by exploiting cyclic prefix redundancy.

Contribution

The paper proposes VFDM, a new precoding method that cancels secondary interference in frequency-selective channels without requiring side information about primary messages.

Findings

VFDM enables secondary users to achieve significant data rates.

VFDM ensures zero interference to primary users.

Numerical results validate the effectiveness of VFDM in realistic scenarios.

Abstract

We consider a cognitive radio scenario where a primary and a secondary user wish to communicate with their corresponding receivers simultaneously over frequency selective channels. Under realistic assumptions that the secondary transmitter has no side information about the primary's message and each transmitter knows only its local channels, we propose a Vandermonde precoder that cancels the interference from the secondary user by exploiting the redundancy 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.