Multi-resolution Spectrum Sensing Research Articles

Spectrum Sensing Methods and RF Architectures for Cognitive Radios

In this paper, we review some of the recent patents on spectrum sensing techniques for cognitive radio (CR) applications. The presented patents are categorized under: 1) spectrum sensing algorithms and architectures, 2) spectrum sensing and data communication and 3) cooperative spectrum sensing. The presented patents include special sensing algorithms that are based on the multi-resolution spectrum sensing (MRSS) approach, which ensures reliability of the spectrum sensing in wireless RF environments. We also discuss a CR patent that includes multiple RF chains to perform simultaneous cognitive tasks. Several patents that consider cooperative sensing are also presented as a solution to the hidden terminal problem inherent in wireless networks. We review the advantages and disadvantages of the presented patents and propose future directions for developing spectrum sensing techniques for CR’s. Keywords: Cognitive radio, cooperative spectrum sensing, dynamic spectrum access, energy detection, multi-resolution spectrum sensing, opportunistic spectrum access, spectrum sensing

A Low-Power Multi Resolution Spectrum Sensing Architecture for a Wireless Sensor Network with Cognitive Radio

Concomitantly with the progress of wireless communications, cognitive radio has attracted attention as a solution for depleted frequency bands. Cognitive radio is suitable for wireless sensor networks because it reduces collisions and thereby achieves energy-efficient communication. To make cognitive radio practical, we propose a low-power multi-resolution spectrum sensing (MRSS) architecture that has flexibility in sensing frequency bands. The conventional MRSS scheme consumes much power and can be adapted only slightly to process scaling because it comprises analog circuits. In contrast, the proposed architecture carries out signal processing in a digital domain and can detect occupied frequency bands at multiple resolutions and with low power. Our digital MRSS module can be implemented in 180-nm and 65-nm CMOS processes using Verilog-HDL. We confirmed that the processes respectively dissipate 9.97mW and 3.45mW.

A multi-resolution spectrum sensing (MRSS) scheme under measurement-based channel models in cognitive radio

Spectrum sensing is one of the key technologies in Cognitive Radios (CRs). Previous works are accomplished under simple channel models, which may lead to unreliable results when it applied to the over-the-air systems. In this paper, we investigate the performance of a Multi-Resolution Spectrum Sensing (MRSS) algorithm under measurement-based channel models in China. MRSS is a wavelet based algorithm which is suitable for non-stationary, wideband signal analysis. Using statistical modeling, measurement-based channel models are presented under typical urban and suburban scenarios in Shanghai, China. Then, the performance of the MRSS algorithm is evaluated under the measurement-based channel models. Simulation results show that, using MRSS, the performance is always better in the scenarios where Line-Of-Sight (LOS) path exist; also, in LOS scenarios, rich scattering effect helps to increase the performance.

A 122-mW Low-Power Multiresolution Spectrum-Sensing IC With Self-Deactivated Partial Swing Techniques

A low-power multiresolution spectrum-sensing (LP-MRSS) IC utilizing self-deactivated partial swing techniques is fabricated in 0.18-¿m complementary metal-oxide-CMOS technology. The LP-MRSS is composed of a low-power digital window generator, analog correlators, low-power pipeline analog-to-digital converters, and a fast-sweeping frequency synthesizer. The LP-MRSS dissipates 122 mW at a 1.8-V supply voltage achieving an approximately 33% power reduction over the previous MRSS IC.

A Fully Integrated UHF-Band CMOS Receiver With Multi-Resolution Spectrum Sensing (MRSS) Functionality for IEEE 802.22 Cognitive Radio Applications

Fast and accurate spectrum sensing is one of the most important functions in a cognitive radio (CR) seeking to use the licensed but unoccupied spectrum segments. In this paper, we present a fully integrated CMOS receiver with a CR spectrum sensing capability in the UHF band. We propose multi-resolution spectrum sensing (MRSS), which is a digitally-assisted analog energy detection technique. Without using bulky analog filters, detection bandwidth can be flexibly controlled by correlating the received analog signals with window signal generated by built-in digital window generator. The integrated chip has been fabricated in a standard 0.18-mumm CMOS technology, and has achieved 32 dB of detection dynamic range with minimum detection sensitivity of -74 dBm by using a 100-kHz cos <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> window.