This paper discusses the automatic modulation classification of weak communication signals using distributed low-cost sensors. The concept of a secondary user in sensor networks is presented and very high-order statistics are used as modulation features. Two feature-based methods, single-variable and multivariable modulation classifiers, are proposed for estimating unknown modulation schemes through single-input multiple-output signal sensing channels. The…
Category: M.TECH OMNET++ PROJECTS
Impact of Primary Network on Secondary Network With Generalized Selection Combining
We propose cognitive spectrum sharing with generalized selection combining (GSC) at the secondary user (SU) in the presence of multiple primary transceivers with outdated channel information. Our main motivation is to determine the impact of GSC and outdated channel information on the outage probability of cognitive spectrum sharing subject to two practical power constraints: 1) maximum transmit power at…
Opportunistic relaying with wireless energy harvesting in a cognitive radio system
In this paper, the performance of opportunistic relay selection (ORS) in a cognitive radio is analyzed over flat Rayleigh fading channels. Data transmission between source and destination is assumed to be entirely performed via the relays. Relay nodes are assumed to have ability to harvest energy from the source signal and use that harvested energy to forward the…
DYWAMIT: Asynchronous Wideband Dynamic Spectrum Sensing and Access System
Dynamic spectrum access (DSA) is a promising solution for enhancing the utilization efficiency of spectrum resources. In DSA, spectrum sensing is crucial and cooperative spectrum sensing has been confirmed as a promising technology that can combat the wireless channel fading problem. Most current works have assumed that the secondary users (SUs) are synchronous with the…
Soft Cooperative Spectrum Sensing Performance Under Imperfect and Non Identical Reporting Channels
Cooperation among cognitive radio users improves the spectrum sensing performance by combining local decisions measured over independent sensing channels, allowing reduction of miss-detection and false alarm probabilities. While most of the works in cooperative spectrum sensing techniques assume perfect channels between the cooperating users, this paper studies the effect of imperfect channels when local users report their sensed…
Energy Efficient COGnitive-MAC for Sensor Networks Under WLAN Co-existence
Energy efficiency has been the driving force behind the design of communication protocols for battery-constrained wireless sensor networks (WSNs). The energy efficiency and the performance of the proposed protocol stacks, however, degrade dramatically in case the low-powered WSNS are subject to interference from high-power wireless systems such as WLANs. In this paper we propose COG-MAC, a novel cognitive medium…
Social Cognitive Heuristics for adaptive data dissemination in Opportunistic Networks
In typical Opportunistic Networking (OppNets) scenarios, mobile devices collaborate to cooperatively disseminate data toward interested nodes. However, the limited resources and knowledge available at each node, compared to possibly vast amounts of data to be delivered, makes it difficult to devise efficient dissemination schemes. Recent solutions propose to use data dissemination algorithms built on human information processing…
Spectrum occupancy measurement: An autocorrelation based scanning technique using USRP
This paper presents a technique for scanning and evaluating the radio spectrum use. This technique determines the average occupancy of a channel over a specific duration. The technique was implemented using Software Defined Radio units and GNU Radio software. The survey was conducted in Grand Forks, North Dakota, over a frequency range of 824 MHz to 5.8 GHz. The results of…
Optimal power allocation for multiple input single output cognitive radios with antenna selection strategies
The opportunistic spectrum access technology is one of the most promising methods for alleviating the spectrum scarcity problem, which enables a secondary user (SU) to utilise a primary user spectrum band that is detected idle. However, the throughput achieved by cognitive radios is limited by the interference constraint imposing on the SU. Multiple input single output antenna techniques…
Bit error rate of underlay decode-and-forward cognitive networks with best relay selection
This paper provides an analytic performance evaluation of the bit error rate (BER) of underlay decode-and-forward cognitive networks with best relay selection over Rayleigh multipath fading channels. A generalized BER expression valid for arbitrary operational parameters is firstly presented in the form of a single integral, which is then employed for determining the diversity order and coding gain…