Category: B.TECH PROJECTS IN OMENT++

We analyse the end-to-end (E2E) outage probabilities (OPs) of zero-forcing beamforming and maximal-ratio-transmission/combining (ZFB-MRT/MRC) for an underlay network, which consists of a single-antenna fixed-gain amplify-and-forward (AF) two-way relay and two multi-antenna terminals. Assuming both path loss effects and small-scale fading and considering both secondary-to-primary (S2P) and primary-to-secondary (P2S) interferences, the exact and asymptotic E2E OPs are…

We consider a cooperative cognitive wireless network scenario where a primary wireless network is co-located with a cognitive (or secondary) network. In the considered scenario, the nodes of the secondary network make local binary decisions about the presence of a signal emitted by a primary node. Then, they transmit their decisions to a fusion center…

In the current study of cognitive relay networks, most related works focus on the effect of interference from secondary users (SUs) to primary receivers (PRs), while neglecting the links from primary transmitters (PTs) to SUs. In this paper, the interference both from SUs to PRs and from PTs to SUs is considered in the analysis…

This paper focuses on the two-user relay-assisted X channel with no channel state information (CSI) available at the transmitter side. Two relaying modes, namely half-duplex decode-and-forward (DF) andcognitive relays, are considered and the degrees of freedom (DoF) are characterized. It is shown that assisted by a half-duplex DF relay that is equipped with 2M antennas, the…

Detecting spectrum holes and efficiently accessing them are the two basic functions that enable acognitive radio (CR) to make use of the licensed spectrums of a primary radio (PR). In this paper, we consider a CR scheme, which opportunistically accesses a PR channel for communication between a pair of nodes based on the stop-and-wait hybrid automatic repeat request (SW-HARQ).…

In this paper we propose an interference alignment (IA) scheme in which the performance of the secondary users (SUs) transmitting their information on the same frequency band of the pre-existing primary links is improved in terms of achievable sum rate without generating any interference on the primary network. In our scenario, in which the primary…

The use of femtocells with cognitive capabilities is considered as a promising way for interference mitigation. The femto access point (FAP) accesses the spectrum either in overlay or underlay fashion. In the former case, the FAPs utilize only radio resources currently not occupied by the macrocell. In the latter case, the whole bandwidth may be…

Inspired by recent developments in full-duplex (FD) communications, we consider an opportunistic spectrum access (OSA) network in which secondary users (SUs) are capable of partial/complete self-interference suppression (SIS). This enables them to operate in either simultaneous transmit-and-sense (TS) or simultaneous transmit-and-receive (TR) modes, with the goal of achieving improved primary user (PU) detection and/or higher SU throughput.…

Cognitive Radio (CR) is very essential in day-to-day life as there is a growing demand for usage of frequency spectrum for different wireless applications. Being an opportunistic communication scenario,cognitive radio performance analysis attains prime significance. Performance analysis of a cognitiveradio scenario in a wireless channel is done by a well-known performance metric Bit Error Rate…

In a recent paper [1], the authors investigated the maximum stable throughput region of a network composed of a rechargeable primary user and a secondary user plugged to a reliable power supply. The authors studied the cases of an infinite and a finite energy queue at the primary transmitter. However, the results of the finite…