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Displaying 76 - 100 of 116

Asynchronous Cooperative MIMO Systems using A Linear Dispersion Structure

February 2, 2010
Author(s)
Hamid Gharavi
In this treatise, we propose a novel family of Asynchronous Cooperative Linear Dispersion Codes (ACLDCs),which is capable of maintaining full diversity in cooperative scenarios even at the presence of asynchronous reception. The linear dispersion structure

A Hybrid Frame Concealment Algorithm for H.264/AVC

January 5, 2010
Author(s)
Hamid Gharavi
In packet-based video transmissions, packets loss due to channel errors may result in the loss of the whole video frame. Recently, many error concealment algorithms have been proposed in order to combat channel errors, however most of the existing

EDITOR IN CHIEF (EIC) MESSAGE

January 1, 2010
Author(s)
Hamid Gharavi
This Editor In Chief's (EIC) message is expected to appear in the January, 2010 issue of the IEEE Transactions on CAS for Video Technology (TCSVT). The editorial team will be under the leadership of the new EIC for a period of two years.

Trends in Multimedia Communications Over Mobile Networks

November 3, 2009
Author(s)
Hamid Gharavi
Increasing demand for high quality multimedia services has been a driving factor in the technological evolution of high bandwidth wireless/mobile communications systems and standards. The most challenging aspect is the support of higher quality video

Directional Antenna for Multipath Ad Hoc Routing

October 15, 2008
Author(s)
Hamid Gharavi, Bin Hu
Multipath routing can be effectively used to maximize the utilization of network resources for real-time traffic. In mobile ad-hoc network environments, this approach can suffer from co-channel interference due to the simultaneous transmission of packets

Efficient Error Concealment for the Whole-frame Loss Based on H.264/AVC

October 15, 2008
Author(s)
Hamid Gharavi, Bo Yan
For low bit-rate video communications, each video frame usually fills the payload of a single network packet. In this situation, the loss of a packet may result in loosing the entire video frame. Currently, most existing error concealment algorithms can

Directional Routing Protocols for Ad Hoc Networks

May 6, 2008
Author(s)
Hamid Gharavi, Bin Hu
This paper presents a directional routing approach for multihop ad-hoc networks, which has been applied to two on-demand routing protocols: namely Dynamic Source Routing (DRS) and Ad Hoc On-Demand Distance Vector Routing (AODV). Both DSR-based and AODV

Spatial Interpolation Algorithm for Error Concealment

April 9, 2008
Author(s)
Hamid Gharavi, Shaoshuai Gao
In this paper, we propose a new spatial interpolation algorithm for Intra-Frame error concealment. The method aims at interpolating areas in the image, which have been affected by packet loss. We have proposed an edge detection technique to aid the

Multi-Channel Mobile Ad-Hoc Links for Multimedia Communications

December 31, 2007
Author(s)
Hamid Gharavi
This paper is mainly concerned with multi-channel transmission of real-time information such as video over multi-hop ad-hoc links. We propose two multi-channel routing protocols. The first is based on single-path routing and aims at suppressing the intra

DSR-Based Directional Routing Protocol for Ad Hoc Networks

November 14, 2007
Author(s)
Bin Hu, Hamid Gharavi
In this paper, a Dynamic Source Routing (DSR)-based directional routing protocol is invoked for wireless ad hoc networks using directional antennas. This is designed to balance the trade-off between co-channel interferences from nodes hops away, and the

3-D Segmentation and Motion Estimation of Range Data for Crash Prevention

June 6, 2007
Author(s)
Hamid Gharavi
In this paper we present a 3-D object segmentation and motion estimation scheme of range video data for crash prevention applications. The segmentation is based on slope values of every point in the scene with which atomic regions are constructed by region

Recursive Motion Estimation of Range Image

April 4, 2007
Author(s)
Hamid Gharavi, Shaoshuai Gao
In this paper, we present an innovative recursive motion estimation technique that can take advantage of the in-depth resolution (range) to perform an accurate estimation of objects that have undergone 3-D translational and rotational movements. This

3-D Motion Estimation Using Range Data

March 1, 2007
Author(s)
Hamid Gharavi, Shaoshuai Gao
Advanced vehicle-based safety and warning systems use laser scanners to measure road geometry (position, curvature), and range to obstacles in order to warn a driver of an impending crash and/or to activate safety devices (air bags, brakes, steering). In

Scanning Advanced Automobile Technology

January 31, 2007
Author(s)
Hamid Gharavi, K V. Prasad, P. Ioannou
The progress of some of the key electrical, electronics, communications, controls and software technologies that enable in-vehicle, vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) functions is presented, in historical, current & futuristic

A Pel-Recursive Motion Estimation Algorithm

January 9, 2007
Author(s)
Hamid Gharavi, H Reza-alikhani
This paper presents a new pel recursive motion estimation algorithm for video coding applications. The derivation of the algorithm is based on Recursive Least-Squares (RLS) estimation that minimizes the mean square prediction error. A comparison with the

Multiple Description Video Coding Over Multiple Path Routing Networks

August 29, 2006
Author(s)
Shaoshuai Gao, Hamid Gharavi
This paper presents a multiple description (MD) video-coding scheme, which uses interlaced high signal to noise ratio (H-SNR) and low signal to noise ratio (L-SNR) coded frames to produce two bit-streams. At the decoder, when both bit-streams are received

Multiple Description Video Coding over Multiple Path Routing Networks

August 1, 2006
Author(s)
Shaoshuai Gao, Hamid Gharavi
This paper presents a multiple description (MD) video-coding scheme, which uses interlaced high signal to noise ratio (H-SNR) and low signal to noise ratio (L-SNR) coded frames to produce two bit-streams. At the decoder, when both bit-streams are received

Multi-Path Multi-Channel Routing Protocol

July 24, 2006
Author(s)
Hamid Gharavi
In this paper we present a DSR-based multi-path Routing protocol, which has been developed for transmission of Multiple Description Coded (MDC) packets in wireless ad-hoc network environments. The protocol is designed to eliminate co-channel interference

Multi-path Multi-Channel Routing Protocol

July 1, 2006
Author(s)
Bo Yan, Hamid Gharavi
In this paper we present a DSR-based multi-path Routing protocol, which has been developed for transmission of Multiple Description Coded (MDC) packets in wireless ad-hoc network environments. The protocol is designed to eliminate co-channel interference

Power Control in Multihop CSMA

June 1, 2006
Author(s)
Hamid Gharavi, Bo Yan
We have implemented a quantum key distribution (QKD) system with polarization encoding at 850 nm over 1 km of optical fiber. The high-speed management of the bit-stream, generation of random numbers and processing of the sifting algorithm are all handled

Control Based Mobile Ad-hoc Networks For Video Communications

May 1, 2006
Author(s)
Hamid Gharavi
This paper presents a feedback control scheme for transmission of video signals over mobile ad-hoc channels. The scheme is a combination of cross-layer (local) feedback and receiver feedback. The receiver feedback is based on the real time transport

Group-Based Ad-hoc Network for Multimedia Communications

October 1, 2005
Author(s)
K Ban, Hamid Gharavi
This paper is concerned with evaluating ad-hoc networks for group-oriented tactical operations. For such operations, a cellular-based ad-hoc network architecture has been constructed for real-time multimedia communications. To assess the suitability of

Real-time Applications for Sensor Networks

April 1, 2005
Author(s)
Hamid Gharavi
We have implemented a quantum key distribution (QKD) system with polarization encoding at 850 nm over 1 km of optical fiber. The high-speed management of the bit-stream, generation of random numbers and processing of the sifting algorithm are all handled

Ad-hoc Network Systems and Applications

November 1, 2004
Author(s)
Hamid Gharavi
We have implemented a quantum key distribution (QKD) system with polarization encoding at 850 nm over 1 km of optical fiber. The high-speed management of the bit-stream, generation of random numbers and processing of the sifting algorithm are all handled

Rate Adaptive Video Transmission Over Ad-Hoc Networks

September 1, 2004
Author(s)
Hamid Gharavi, K Ban
In mobile ad-hoc network environments where the network topology is expected to change considerably, providing reliable video communications is a challenging task. This paper is mainly concerned with developing a packet control mechanism to reduce bursts
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