We propose a bidirectional Radio-over-Fiber (RoF) system with multi-band signals generation technique using a single phase modulator (PM). At central office (CO), a PM is used to modulate optical carrier and generated signal is transmitted through a single mode fiber (SMF). At base station (BS), three different signals are generated from the received optical signal, including 60 GHz millimeter ...

Collision avoidance is critical for the performance of contentionbased medium access mechanism such as CSMA. In this paper, the IEEE 802.11-based MAC protocol is enhanced for performance improvements in multi-hop ad-hoc wireless networks. The protocol behavior of hidden terminals in carrier sensing range[10] is important for end-to-end performance. There are several mechanisms defined in IEEE 8...

In this paper, we investigate the influence of different Walsh-Hadamard (WH) code allocation techniques on the performance of multi-carrier code division multiple access (CDMA) systems in the presence of high power amplifier (HPA) non-linearities. We consider two different multi-carrier CDMA schemes: multi-carrier CDMA (MCCDMA) and multi-carrier direct sequence CDMA (MC-DSCDMA) and analyse thei...

We investigate the problem of maximizing network capacity sustained by IEEE 802.11 DCF in multi-hop wireless networks. By explicitly incorporating two key system parameters – carrier sense threshold and transmit power – into our analysis, we derive an analytical relation between network capacity and the level of spatial reuse characterized by physical carrier sense. In homogeneous networks wher...

Wireless Sensor Networks are a group of sensors with inadequate power sources that installed in particular region to gather information from the surroundings. Designing energy-efficient data gathering methods large-scale (WSN) is one most difficult areas study. As every sensor node has finite amount energy. Battery significant source WSN. Clustering well-known technique for enhancing feature In...

In this study, a new energy-efficient hybrid opportunistic cooperative (HOC) transmission protocol is proposed for single-carrier frequency division multiple access (SC-FDMA)-based cooperative networks. The author considers a single source–destination pair and multiple relays network. The proposed protocol improves the energy efficiency of SC-FDMAbased networks by selecting the most energy-effi...

Wireless cooperative networks, which are based on exploiting coordination among multiple access nodes, has been considered as a promising approach to improve the spectral efficiency, reduce the energy consumption, and extend the network coverage of future wireless communication systems. In practice, the actual benefit of multi-node cooperation is affected by a variety of factors, including the ...