With the increasing emergence of new wireless systems and the explosive development of mobile internet applications, the demands on Radio Frequency spectrum have been constantly increasing, and therefore, the related demands for bandwidth, wireless communication technology is facing a potentially scarcity of radio spectrum resources. However, spectrum measurement campaigns have shown that the s...

In several applications for automation, radio transmission could be a good alternative to wired field busses [8]. The advantages are an easy, fast and low cost installation scenario in common with the possibility of flexible device placing. But, the specifics of radio require a very specialized protocol stack which effects the whole system architecture. Starting from the requirements of buildin...

Narrowband radio transmitters like radio amateurs and broadcast radio stations are considered to be a serious problem for highbitrate data transmission over twisted pairs. Due to its high power level, radio frequency interference (RFI) has the potential of overloading the receiver’s analog-to-digital converter (ADC). Once the ADC is in saturation, any countermeasure taken in digital domain will...

This paper describes overview and definitions about Multiple Input Multiple Output (MIMO) formats which can be used in hybrid Free Space Optics/Radio Frequency (FSO/RF) links. Free space optical links allow obtain high speed data transmission without optical fibers. This type of communication is dependent on weather properties and line of sight is needed. This fact has negative influence on inf...

In Wireless Sensor Networks (WSNs), transmission errors occur frequently due to node failure, battery discharge, contention or interference by objects. Although Directed Diffusion has been considered as a prominent data-centric routing algorithm, it has some weaknesses due to unexpected network errors. In order to address these problems, we proposed a radio-aware routing algorithm to improve th...

In this paper, we propose a green radio resource allocation (GRRA) scheme for LTE-advanced downlink systems with coordinated multi-point (CoMP) transmission to support multimedia traffic. The GRRA scheme defines a green radio utility function, which is composed of the required transmission power, assigned modulation order, and the number of coordinated transmission nodes. By maximizing this uti...

For this purpose, a technical approach for all.and improve the spectrum utilization, cognitive radio concept has been evolved. Cognitive radios are the radio systems that autonomously coordinate the. Levels for the cognitive radio system. We have studied intelligent channel selection for transmission of data and control information based on.Fundamental Design Tradeoffs in Cognitive Radio System...

A wireless ad hoc network is a collection of radio devices (transceivers) located in a geographic region. Each node is equipped with an omnidirectional antenna and has limited transmission power. A communication session is established either through a single-hop radio transmission if the communication parties are close enough, or through relaying by intermediate devices otherwise. For this reas...

Software Defined Radio (SDR) and Cognitive Radio (CR) are the key enabling technologies to overcome the spectrum scarcity problem a bit, by supporting dynamic spectrum access in which either a network or a wireless node reconfigures its transmission or reception parameters to communicate efficiently, avoiding interference with licensed or unlicensed users. CR senses the environment and enables ...

Wireless body sensor network systems (WB-SNSs) can use diverse radio modules. However, previous studies did not consider different characteristics of radio modules, which deeply impact the performance of WBSNSs. In this paper, we analyze the performance of WB-SNSs using the representative radio modules CC2420 and CC1000. In this environment, we collected log data from real sensor devices deploy...