We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the c...

The atmospheric icing parameters are being measured nowadays with the aid of more customized yet limited commercial equipment. The parameters include atmospheric ice detection, icing load and icing rate. The robustness of such equipment is usually under scrutiny when it comes to cold/harsh environment operations. This phenomenon was experienced consistently by the atmospheric Icing Research Tea...

In this paper we propose a soft-hard combination scheme, called SHC scheme, for cooperative spectrum sensing in cognitive radio networks. The SHC scheme deploys a cluster based network in which Likelihood Ratio Test (LRT)-based soft combination is applied at each cluster, and weighted decision fusion rule-based hard combination is utilized at the fusion center. The novelties of the SHC scheme a...

Compressive sensing (CS) with sparse random matrix for the random sensing basis reduces source coding complexity of sensing devices. We propose a downsampling scheme to this framework in order to further reduce the complexity and improve coding efficiency simultaneously. As a result, our scheme can deliver significant gains to a wide variety of resource-constrained sensors. Experimental results...

Cognitive radio is a promising technology to improve the utilization of wireless spectrum resources. A serious threat to cognitive radio networks (CRN) which sense the spectrum in a cooperative manner is the transmission of false spectrum sensing data by malicious secondary nodes, namely spectrum sensing data falsification (SSDF) attacks. SSDF attackers start to attack the network in the case o...

To improve the channel throughput and the fairness of random access channels, we propose a new backoff algorithm, namely, Sensing Backoff Algorithm (SBA). A novel feature of the SBA scheme is the sensing mechanism, in which every node modifies its backoff interval according to the results of the sensed channel activities. In particular, every active node sensing the successful transmission decr...

With increasing demand of new wireless applications and increasing number of wireless user’s problem of spectrum scarcity arises. Cognitive Radio technology supports dynamic spectrum access to address spectrum scarcity problem. Reliability of cognitive operation entirely depends upon how effectively task of spectrum sensing has been performed. Spectrum sensing is a process of discovering voids ...

Remote Sensing is simply defined as the observation of an object from some distance. By using the observation of object we can collect the information of an object without any physical contact with that object. We present a new technique for the compression of remote sensing images based on oriented wavelet transform. A 3D-Oriented Wavelet Transform (OWT) is introduced for efficient remote sens...

Cognitive radio is a revolutionary paradigm to migrate the spectrum scarcity problem in wireless networks. In cognitive radio networks, collaborative spectrum sensing is considered as an effective method to improve the performance of primary user detection. For current collaborative spectrum sensing schemes, secondary users are usually assumed to report their sensing information honestly. Howev...

In this contribution, a hardware platform for cooperative sensing networks is presented with the use of Roy ́s Largest Root Test, also known as a blindly combined energy detection scheme, such that the system is configured with three ETTUS USRPs N210 and one computer for processing. The hardware experiments were validated with simulations, and the results show that the cooperative scheme outperf...