Information theoretic capacity of the cellular uplink - average path loss approximation

In this paper we investigate the information theoretic capacity of the uplink of a cellular system where all base station receivers jointly decode the received signals (“hyper-receiver”). Considering a distance depended power-law path loss and a more realistic Rician fading environment, we model a variable cell density network with geographically distributed user terminals. Multiple tiers of interference are considered and using an average path loss approximation model the analytical result for the per cell sum-rate capacity is found. We examine the various parameters that are affecting the capacity of the system. Especially the effect of the user distribution across the cells and the density of the cells in the cellular system is investigated. We validate the numerical solutions with Monte Carlo simulations for random fading realizations and we interpret the results for the real-world systems

Capacity of Cellular Uplink with Multiple Tiers of Users and Path Loss

Abstract-With the emergence and continuous growth of wireless data services, the value of a wireless network is not only defined by how many users it can support, but also by its ability to deliver higher data rates. Information theoretic capacity of cellular systems with fading is usually estimated using models originally inspired by Wyner's Gaussian Cellular Multiple Access Channel (GCMAC). In this paper we extend this model to study the cellular system with users distributed over the cellular coverage area. Based on the distance from the cellsite receiver, users are grouped as tiers, and received signals from each tier are scaled using a distance dependent attenuation factor. The optimum capacity in fading environment is then found by calculating the path-loss for users in each tier using a specific path-loss law and some interesting insights are derived. The results correspond to a more realistic model which boils down to Wyner's model with fading, with appropriate substitutions of parameter values. The results are verified using Wyner's model with fading and Monte-Carlo simulations. Insights are provided for the real world scenarios

Hadamard upper bound on optimum joint decoding capacity of Wyner Gaussian cellular MAC

This article presents an original analytical expression for an upper bound on the optimum joint decoding capacity of Wyner circular Gaussian cellular multiple access channel (C-GCMAC) for uniformly distributed mobile terminals (MTs). This upper bound is referred to as Hadamard upper bound (HUB) and is a novel application of the Hadamard inequality established by exploiting the Hadamard operation between the channel fading matrix G and the channel path gain matrix Ω. This article demonstrates that the actual capacity converges to the theoretical upper bound under the constraints like low signal-to-noise ratios and limiting channel path gain among the MTs and the respective base station of interest. In order to determine the usefulness of the HUB, the behavior of the theoretical upper bound is critically observed specially when the inter-cell and the intra-cell time sharing schemes are employed. In this context, we derive an analytical form of HUB by employing an approximation approach based on the estimation of probability density function of trace of Hadamard product of two matrices, i.e., G and Ω. A closed form of expression has been derived to capture the effect of the MT distribution on the optimum joint decoding capacity of C-GCMAC. This article demonstrates that the analytical HUB based on the proposed approximation approach converges to the theoretical upper bound results in the medium to high signal to noise ratio regime and shows a reasonably tighter bound on optimum joint decoding capacity of Wyner GCMAC

Framework to Compare the Uplink Capacity of the Cellular Systems with Variable Inter Site Distance

In this paper we derive the information theoretic capacity of the uplink of a cellular system with variable inter site distance and a generalised fading environment. The capacity is shown to be a direct function of the ratio of total received signal power (from within and outside of a cell) to the AWGN noise power, at any BS. This ratio is defined as the rise over thermal (RoT). It is shown that the variation in system parameters like the path loss exponent, number of users, transmit power constraint and the inter site distance, changes the region of operation on a capacity-versus-RoT curve. Results are interpreted for practical channel models and it is shown that RoT provides a useful framework to compare various practical systems

Capacity of sectorized cellular systems: an information theoretic perspective

No abstract available

Capacity of sectorized cellular systems: an information theoretic perspective

No abstract available

Sum Rate of Linear Cellular Systems with Clustered Joint Processing

In this paper we derive the sum rate of the uplink of a linear network of cells when clustered coordinated processing is adopted among the base stations in a generalised fading environment. Various cluster isolation schemes along with an interference allowance scheme are analysed and compared in terms of achievable sum rate with each other and to the optimum case of a system with central processor. Numerical results are produced for a real-world scenario

Capacity of Sectorized Cellular Systems: An Information Theoretic Perspective

In this work, we formulate the information theoretic capacity of the sectorized cellular system for the uplink. We model a planar cellular system in which user terminals (UTs) are served by perfect directional antennas dividing the cell coverage area into perfectly non-interfering sectors. Assuming the joint decoding of the signals received at the antennas (hyper-receiver), we find the information theoretic uplink capacity in the presence of a general fading environment. To find the capacity, we apply a known technique to obtain the eigenvalues of a block-circulant matrix with non-circulant blocks. We show how the capacity is increased in comparison to the non-sectorized single antenna system and we investigate the asymptotic behaviour when the number of sectors grows large. We validate the numerical solutions with Monte Carlo simulations for random fading realizations and we interpret the results for the real-world systems

Capacity of Sectorized Cellular Systems: An Information Theoretic Perspective

In this work, we formulate the information theoretic capacity of the sectorized cellular system for the uplink. We model a planar cellular system in which user terminals (UTs) are served by perfect directional antennas dividing the cell coverage area into perfectly non-interfering sectors. Assuming the joint decoding of the signals received at the antennas (hyper-receiver), we find the information theoretic uplink capacity in the presence of a general fading environment. To find the capacity, we apply a known technique to obtain the eigenvalues of a block-circulant matrix with non-circulant blocks. We show how the capacity is increased in comparison to the non-sectorized single antenna system and we investigate the asymptotic behaviour when the number of sectors grows large. We validate the numerical solutions with Monte Carlo simulations for random fading realizations and we interpret the results for the real-world systems