On the Maximum Sum-rate Capacity of Cognitive Multiple Access Channel

TL;DR

This paper analyzes the maximum sum-rate capacity of a cognitive multiple access channel where multiple cognitive users share the same receiver with primary users, considering side information and capacity constraints.

Contribution

It characterizes the maximum sum-rate capacity and optimal power allocation for cognitive users without affecting primary transmission capacity.

Findings

Maximum sum-rate capacity is derived.

Optimal power allocation strategies are identified.

Primary transmission capacity remains unaffected.

Abstract

We consider the communication scenario where multiple cognitive users wish to communicate to the same receiver, in the presence of primary transmission. The cognitive transmitters are assumed to have the side information about the primary transmission. The capacity region of cognitive users is formulated under the constraint that the capacity of primary transmission is not changed as if no cognitive users exist. Moreover, the maximum sum-rate point of the capacity region is characterized, by optimally allocating the power of each cognitive user to transmit its own information.