Date Added: Feb 2013
This paper focuses on a cognitive radio network consisting of a Secondary User (SU) equipped with Orthogonal Frequency-Division Multiplexing (OFDM) technology able to access N randomly fading frequency bands for transmitting delay-insensitive (e.g. data) as well as delay-sensitive (e.g. voice or video) data. Each band is licensed to a distinct delay-sensitive Primary User (PU) interested in meeting a minimum rate guarantee for delay-sensitive services with a maximum allowable primary outage probability or a Primary Outage Constraint (POC). Typically, a PU is oblivious to the SU's existence and has its own power policy based on the Channel Side Information (CSI) of its direct gain between the PU transmitter and the PU receiver only.