In the environment of distribute data stream systems, the available communication bandwidth is a bottleneck resource. It is significant to reduce the communication overhead as possible for improving the availability of communication bandwidth with the constraint of the precision of queries. In this paper, we propose a new method for transferring data streams in distributed data stream systems, ...

A MIMO-OFDM wireless communication system is a combination of MIMO and OFDM Technology. The combination of MIMO and OFDM produces a powerful technique for providing high data rates over frequency-selective fading channels. MIMO-OFDM system has been currently recognized as one of the most competitive technology for 4G mobile wireless systems. MIMO-OFDM system can compensate for the lacks of MIMO...

Last years, Wavelet Packet Modulation (WPM) or Wavelet Packet Transform based Orthogonal Frequency Division Multiplexing (WPT-OFDM) have been introduced to wired and wireless communication fields as efficient Multicarrier Modulation (MCM) techniques. The wavelets have interesting features such as flexibility, compatibility and localization in both time and frequency domains with no need to use ...

We propose a new bandwidth and power efficient signaling scheme for achieving high data rates over wideband radio channels exploiting bandwidth efficient OFDM modulation, multiple transmit and receive antennas and large frequency selectivity offered in typical low mobility indoor environments. Due to its maximum achievable transmit diversity gain and large coding gain, space-frequency turbo cod...

–One of the essential components of recent communications is Orthogonal Frequency Division Multiplexing (OFDM). Handling bad conditions, high bandwidth and using the available spectral efficiently are some of its characteristics. Hence, it has replaced old communication technologies in many systems such as wireless networks and 4G mobile communications. In this paper, Effects of fading channels...

This paper presents a new cooperative ARQ protocol for a hybrid mobile wireless sensor network. The mobile relay nodes decode the signal from the source sensor using cyclic redundancy check (CRC) and forward it to the destination sink. A distributed relay selection that exploits overhearing of inter-relay node transmission is employed to achieve higher selection diversity gain during retransmis...

The global telecommunications network has seen massive expansion over the last few years. Optical communication through clear atmosphere provides a means for high data rate communication over relatively short distances (e.g. 2km). However, the turbulence in the atmosphere leads to fades of varying depths, some of which may lead to heavy loss of data. Free space optical communication system usin...

Traditional methods of wireless communications are saturating in terms of data rate, frequency spectrum and reliability. Visible light communications has attracted interests in many fields due to widespread commercial availability of LED lights and partly due to limited bandwidth available on the radio communication. It is even more effective for Internet-of-Things(IoT) devices which require ve...