In this paper, an imaging components transmission scheme for the improvement of multipath delay resolution in a Fractional Sampling (FS) OFDM receiver is proposed. FS has been proposed as a diversity scheme and achieves path diversity by enlarging the bandwidth of the baseband filters in order to transmit the imaging components of the desired signal. However, FS is not able to achieve diversity...

In DS-CDMA system, overcoming the problem of multiple access interference (MAI) and multi-path fading is imperative to improve the performance. A number of multi-user detection (MUD) algorithms have been proposed to mitigate the MAI. This report simulates the performance of two MUD schemes known as successive interference cancellation (SIC) and parallel interference cancellation (PIC) and compa...

Voice traffic on the Internet (VoIP) is poised to grow rapidly but the Internet is not engineered for such delaysensitive applications. We show how the end-user quality of many VoIP calls can be improved by rerouting them in an intermediate overlay network and thought the use of various path-diversity and error-coding techniques. We present an overlay network (OverPhone) that is tuned to optimi...

Abstract The site-diversity can be applied to multicarrier-CDMA (MC-CDMA) to improve the bit error rate (BER) performance for a user with weak signal power, resulting in the increased link capacity. In this paper, downlink capacity under shadowing environment is considered when base stations involved in site-diversity operation are determined based on average received power. The impacts of path...

The Max-Min Diversity Problem (MMDP) consists in selecting a subset of elements from a given set in such a way that the diversity among the selected elements is maximized. The problem is NP-hard and can be formulated as an integer linear program. Since the 1980s, several solution methods for this problem have been developed and applied to a variety of fields, particularly in the social and biol...

In mobile communication systems, the received signal power varies due to fading, shadowing and path loss, resulting in the transmission performance degradation. Transmit antenna diversity is a promising technique to improve the transmission performance. For the downlink transmission, the outage probability in a service area can be improved by distributing the transmit antennas over the service ...

As more applications migrate to IP networks, ensuring a consistent level of service is increasingly important. One option is for the network to offer service guarantees. Another is to leverage the path diversity that the Internet intrinsically offers. Our focus is on understanding if and when one can indeed take advantage of multiple disjoint paths to improve performance. We consider an environ...

In today's BGP routing architecture, traffic delivery is in general based on single path selection paradigms. The lack of path diversity hinders the support for resilience, traffic engineering and QoS provisioning across the Internet. Some recently proposed multi-plane extensions to BGP offer a promising mechanism to enable diverse inter-domain routes towards destination prefixes. Based on thes...

We propose multi-stream transmission of real-time voice over best-effort packet networks such as today’s Internet, where multiple redundant descriptions of the voice stream are sent over independent network paths. At the receiver, multi-stream adaptive playout scheduling is employed to improve the tradeoff among delay, late loss rate, and speech quality. Experiments over the Internet suggest la...

In general, the use of angle-diversity receivers makes it possible to reduce the impact of ambient light noise, path loss and multipath distortion, in part by exploiting the fact that they often receive the desired signal from different directions. Angle-diversity detection can be performed using a composite receiver with multiple detector elements looking in different directions. These are cal...