Improvement of active interference cancellation: avoidance technique for OFDM cognitive radio

In cognitive radio (CR), a cognitive user must cease transmission or reduce the transmit power at the band where a primary system (PS) is detected. To this end, a popular method for orthogonal frequency division multiplexing (OFDM) based CR is the active interference cancellation (AIC) which tunes t...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on wireless communications 2009-12, Vol.8 (12), p.5928-5937
Main Authors: HUANG, Shih-Gu, HWANG, Chien-Hwa
Format: Article
Language:English
Subjects:
Active interference cancellation
Applied sciences
Bit error rate
Cancellation
Chromium
Cognitive radio
Complexity
Contracts
Costs
Detection, estimation, filtering, equalization, prediction
Exact sciences and technology
Information, signal and communications theory
Interference
Interference cancellation
Interference suppression
least squares with a quadratic inequality constraint
Matrices
Measurement
minimax criterion
Modulation, demodulation
Multiplexing
OFDM modulation
Orthogonal Frequency Division Multiplexing
orthogonal frequency division multiplexing (OFDM)
Polystyrene resins
Radio
Radiocommunication specific techniques
Radiocommunications
Reduction
Signal and communications theory
Signal, noise
Subcarriers
Telecommunications
Telecommunications and information theory
Throughput
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In cognitive radio (CR), a cognitive user must cease transmission or reduce the transmit power at the band where a primary system (PS) is detected. To this end, a popular method for orthogonal frequency division multiplexing (OFDM) based CR is the active interference cancellation (AIC) which tunes the modulation of some subcarriers to minimize the interference to PS. This paper focuses on complexity reduction and performance enhancement of AIC. The former relies on the findings that (i) many matrices in AIC depend only on the PS bandwidth and are irrelevant to where PS resides, and (ii) statistical relation among the data carried by subcarriers for interference suppression is available. For the latter, performance metric of AIC that minimizes the total residual power at the PS band is adjusted to minimizing the largest residual power, avoiding the undesirable situation that, although the total power is the least, part of the band is severely interfered. Spectrum overshoot problem occurred in an ultra-wideband (UWB)-CR system is also addressed. Simulation results demonstrate that complexity reduction of AIC induces negligible performance loss, and the new performance metric significantly reduces the number of subcarriers required to suppress the interference below a certain level.
ISSN:1536-1276
1558-2248
DOI:10.1109/TWC.2009.12.081277