The cellular infrastructure known as the Radio Access Network (RAN) has been evolving since the first analog FM cellular solution (first generation or 1G) in the 1980s. During this evolution, the Radio Access Technology (RAT) moved from GSM to LTE and the network topology changed from circuit-switched (TDM) to packet-switched (IP) with continual reduction in latency, improved throughput, spectral efficiency and peak speeds. These changes translated into a new infrastructure that is faster, smarter, and more elastic in its use of resources. This transition requires more processing power and intelligence in the Basestation or eNodeB.
The basestation is now evolving to a super-intelligent wireless router. Specifically, the basestation, or eNodeB, now processes the entire PHY, MAC, Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Radio Resource Control (RRC) for multiple interface standards, at 10 times the data throughput.
These advancements result in a “soft/flexible” basestation supporting multiple standards at the right price. Furthermore, basestation solutions must scale from picocells, to microcells, and to macrocells .
OEMs’ desire to re-use their basestation chassis, the high processing requirements for next-generation basestation architectures, and the need to reduce overall system latency and address both flexibility and scalability are all driving the need for highly integrated system on a chip (SoC) solutions with both hardware and software flexibility for interfaces and processing with inherent scalability. Figure 1 illustrates typical macro basestation architecture.
Figure 1. Typical Basestation Layer 1 Block Diagram for PUSCH and PDSCH processing