3 research outputs found
Spectral Efficiency Optimized Adaptive Transmission for Cognitive Radios in an Interference Channel
In this paper, we consider a primary and a cognitive user transmitting over a
wireless fading interference channel. The primary user transmits with a
constant power and utilizes an adaptive modulation and coding (AMC) scheme
satisfying a bit error rate requirement. We propose a link adaptation scheme to
maximize the average spectral efficiency of the cognitive radio, while a
minimum required spectral efficiency for the primary user is provisioned. The
resulting problem is constrained to also satisfy a bit error rate requirement
and a power constraint for the cognitive link. The AMC mode selection and power
control at the cognitive transmitter is optimized based on the scaled signal to
noise plus interference ratio feedback of both links. The problem is then cast
as a nonlinear discrete optimization problem for which a fast and efficient
suboptimum solution is presented. We also present a scheme with rate adaption
and a constant power. An important characteristic of the proposed schemes is
that no negotiation between the users is required. Comparisons with underlay
and interweave approaches to cognitive radio with adaptive transmission
demonstrate the efficiency of the proposed solutions.Comment: accepted in ICC 200
Spectral Efficiency Optimization for an Interfering Cognitive Radio with Adaptive Modulation and Coding
In this paper, we consider a primary and a cognitive user transmitting over a
wireless fading interference channel. The primary user transmits with a
constant power and utilizes an adaptive modulation and coding (AMC) scheme
satisfying a bit error rate requirement. We propose a link adaptation scheme to
maximize the average spectral efficiency of the cognitive radio, while a
minimum required spectral efficiency for the primary user is provisioned. The
resulting problem is constrained to also satisfy a bit error rate requirement
and a power constraint for the cognitive link. The AMC mode selection and power
control at the cognitive transmitter is optimized based on the modified signal
to noise plus interference ratio feedback of both links. The problem is then
cast as a nonlinear discrete optimization problem for which a fast and
efficient suboptimum solution is presented. We also present a scheme with rate
adaptive and constant power cognitive radio. An important characteristic of the
proposed schemes is that no computation or coordination overhead is imposed on
the primary radio due to the cognitive radio activity. Numerical results and
comparison with the interweave approach to cognitive radio demonstrate the
efficiency of the proposed solutions.Comment: 26 pages, 7 figures submitted to IEEE journal on selected areas in
communicatio
Spectral Efficiency Optimized Adaptive Transmission for Cognitive Radios in an Interference Channel
Abstract β In this paper, we consider a primary and a cognitive user transmitting over a wireless fading interference channel. The primary user transmits with a constant power and utilizes an adaptive modulation and coding (AMC) scheme satisfying a bit error rate requirement. We propose a link adaptation scheme to maximize the average spectral efficiency of the cognitive radio, while a minimum required spectral efficiency for the primary user is provisioned. The resulting problem is constrained to also satisfy a bit error rate requirement and a power constraint for the cognitive link. The AMC mode selection and power control at the cognitive transmitter is optimized based on the scaled signal to noise plus interference ratio feedback of both links. The problem is then cast as a nonlinear discrete optimization problem for which a fast and efficient suboptimum solution is presented. We also present a scheme with rate adaption and a constant power. An important characteristic of the proposed schemes is that no negotiation between the users is required. Comparisons with underlay and interweave approaches to cognitive radio with adaptive transmission demonstrate the efficiency of the proposed solutions