Hybrid compression and message-sharing strategy for the downlink cloud radio-access network

Abstract

Abstract-Cloud radio-access network (CRAN) is a wireless cellular network architecture in which the base-stations are connected to a cloud-computing based central processor with digital backhaul links. In this setting, the base-stations can be thought of as relays between the central processor and the user terminals. This paper considers the downlink of a cloud radioaccess network with finite-capacity backhaul links. We model the overall network as a relay broadcast channel, and propose a hybrid compression and message-sharing strategy for the downlink transmission. This paper further proposes numerical techniques for optimizing the quantization noise level in the compression part of the hybrid precoding scheme. We compare the system-level performance of the proposed scheme with the pure compression and the pure message sharing schemes to show the benefit of the hybrid strategy for the downlink CRAN.

Joint Decoding and Adaptive Compression with QoS Constraint for Uplinks in Cloud Radio Access Networks

“…This improvement comes from the correlation between RRHs to which distributed source coding can be applied [12]. A hybrid compression and message-sharing is proposed in [13] that allows the BSs to alternatively chose to perform a mix of compression and data-sharing on downlinks. We would emphasize that these joint compression techniques are investigated under information theoretic aspect.…”

Capacity Bounds on the Downlink of Symmetric, Multi-Relay, Single-Receiver C-RAN Networks

“…We specialize Theorem 1 to the symmetric Gaussian C-RAN defined in (6) and (7) where P m = P for all m = 1, . .…”

“…We refer to [1][2][3] and the references therein for an overview of the challenges and coding techniques for C-RANs. Several coding schemes have been proposed in recent years for the downlink of C-RANs including message sharing [4], backhaul compression [5], hybrid schemes [6] and generalized data sharing using Marton's coding [7,8]. The paper [9] gives an upper bound on the sum-rate of two-relay C-RANs with two users and numerically compares the performance of the aforementioned schemes with the upper bound.…”

Fronthaul compression and optimization for cloud radio access networks

“…Numerous research efforts have recently investigated the compression of C-RAN, from both information-theoretic perspective [5][6][7][8], which designs and optimizes the quantization noise to maximize the achievable sum rate, and practical system point of view [11], [12], which minimizes redundancy of control information in common public radio interface package. It is shown, in general, that the joint design of the precoding and quantization noise matrix can significantly improve the system sum rate over separate designs [5].…”

“…It is shown, in general, that the joint design of the precoding and quantization noise matrix can significantly improve the system sum rate over separate designs [5]. Additional performance gain can be achieved by optimizing the test channel [9] or performing hybrid compression and message-sharing strategy [6]. From the practical system perspective, efficient compression can be performed in both time-and frequencydomains (sub-carrier compression) [1].…”