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In heterogeneous networks where macro cells and metro cells use the same frequency band to communicate with their respective users, the major problem limiting performance is the interference caused by macro cells to metro cells. The information theoretic result known as dirty paper coding provides a way to address this problem and significantly improve the performance of heterogeneous networks with co-channel deployment. In this paper, we show how a simple dirty paper coding scheme employing Tomlinson-Harashima pre-coding with partial interference pre-subtraction can be employed by metro cells to mitigate the interference caused by macro cells. A performance study included in this paper shows that the proposed dirty paper coding scheme can lead to significant improvement in user rate statistics. [ABSTRACT FROM AUTHOR]

In this paper, we present a practical method to construct dirty paper coding (DPC) schemes using sum codes. Unlike the commonly used approach to DPC where the coding scheme involves concatenation of a channel code and a quantization code, the proposed method embodies a unified approach that emulates the binning method used in the proof of the DPC result. Auxiliary bits are used to create the desired number of code vectors in each bin. Sum codes are obtained when information sequences augmented with auxiliary bits are encoded using linear block codes. Sum-code-based DPC schemes can be implemented using any linear block code, and entail a relatively small increase in decoder complexity when compared to standard communication schemes. They can also lead to significant reduction in transmit power in comparison to standard schemes. [ABSTRACT FROM AUTHOR]

Focuses on the relationship between the signal-to-noise ratio and the frame error rate (FER) for frame (block)-oriented convolutionally coded transmissions over facing channels subject to practical power control algorithms. Estimation of Viterbi decoder performance over channels with time-varying received signal levels; Details on the quantification of the convolutional code performance through the FER and E.../N...; Models that the relationship had been used to develop.

As new broadband networks based on the asynchronous transfer mode (ATM) protocol emerge to support a variety of services, the need for analytical models and tools for sizing network components carrying mixtures of different kinds of traffic will be increasingly felt. This paper presents a simple, yet efficient algorithm for sizing trunks carrying mixtures of constant and variable bit rate traffic. It combines theoretical results for the multi-dimensional Erlang model and the concept of equivalent bandwidth with some heuristic arguments to produce an analytic method for sizing trunks subject to blocking and quality of service constraints for traffic classes. [ABSTRACT FROM AUTHOR]

The concept of the equivalent bandwidth of a source seems highly attractive for characterizing ATM traffic sources as it can be used to treat constant as well as variable bit rate sources within a common framework. In this paper we review the concept of equivalent bandwidth based on asymptotic results and study the performance of a few admission criteria which use this concept in one way or another. A major finding is that with appropriate refinements to account for the possible statistical multiplexing gain at small to moderate buffer sizes, the well-known conservatism of the asymptotic equivalent bandwidth based criteria can be overcome. We also .discuss how these criteria would perform in practical situations where the traffic sources are incompletely characterized, or where they are specified in terms of leaky-bucket based traffic descriptors. [ABSTRACT FROM AUTHOR]

Cellular heterogeneous networks (HetNets), which are realized through shared carrier deployments of macrocells and small cells, are widely seen as a potential solution to serve growing data capacity demands. While these networks pose significant challenges in interference management, much of the focus in earlier efforts has been limited only to small-cell range expansion in the downlink. In this paper, we provide a comprehensive analysis of interference management techniques applicable to the uplink of cellular HetNets, with the goal of characterizing and improving edge user (e.g., 5th percentile) performance. In particular, we propose and study virtual soft-handoff (VSHO), which offers a low-complexity and low-overhead solution that exploits the link asymmetry observed in the uplink geometry of HetNets. VSHO exploits the fact that, in the uplink, an edge macro user who suffers from very low throughput may be closer to a nearby small cell than its own macrocell. The intuition is that such macro users should have better decoding opportunity when their signals are processed at the nearby small cell with better channel conditions. We also study how interference cancelation (IC) and interference avoidance through resource blanking can be incorporated into our VSHO proposal for further throughput gains. In addition to the VSHO techniques outlined in this paper, we also analyze other candidate techniques available in the Third Generation Partnership Project Long-Term Evolution (3GPP-LTE), such as cell-range expansion (CRE) and joint processing, to present a unified view of interference management options available in HetNets. [ABSTRACT FROM PUBLISHER]