Quantitative analysis of split base station processing and determination of advantageous architectures for LTE

Abstract

Centralization of the baseband processing in radio access networks may reduce radio site operations costs, reduce capital costs, and ease implementation of multi-site coordination mechanisms such as coordinated multipoint transmission and reception (CoMP). However, the initial architecture proposals for a centralized Long Term Evolution (LTE) deployment using transport of radio samples require a high-bandwidth, low-latency interconnection network. This may be uneconomical, or it may only be cost effective for a limited number of sites. To mitigate that deficiency without sacrificing the benefits of centralized processing, we identified alternative interfacing options between central and remote units. To do so we analyzed possible splits of the Long Term Evolution (LTE) baseband processing chain for their bandwidth and latency requirements. Next, we analyzed the operational impacts of potential splits based on a number of criteria including ease of CoMP introduction, the possibility of realizing pooling gains, and the ability to update the system and introduce new features. Based on our results, we propose architectures that can leverage the benefits of centralization at a much-reduced cost.