Towards unified VLSI architectures of radio-interfaces in distributed base transceiver stations

The concept of distributed base stations and the remote radio heads (RRH) is an emerging trend and is being used significantly in the fast expanding heterogeneous wireless networks. Standard interface protocols to connect the digital baseband module and the analogue radio modules in modern base transceiver stations (BTS) has received special attention and is being intensely pursued by the industry. These interfaces between the baseband unit (BBU) and the remote radio heads (RRH) are termed as radio interfaces. The radio interfaces help in realizing the deployment of distributed base stations and offer significant cost savings to the wireless service providers. The use of radio interfaces also offers tremendous flexibility in network design and deployment. CPRI, OBSAI-RP3 and ORI are the three main radio standards supported by respective interest groups. Ideally, it is desirable to have a single radio interface standard. However with these competing standards in the market the component manufacturers are presented with challenging scenario of accommodating multiple radio interfaces in their standard ASIC's. This paper reviews these standards, derives similarities between required hardware components of the standards and present recommendations to arrive at a unified VLSI architecture of the radio interfaces in modern Base Stations.