Today’s multi-standard Basestations (BTS) consist of multiple Remote Radio Head (RRH) which include all analog, RF, and Power sub-systems - distributed next to the masts where antennas are deployed. These RRHs are connected to a Digital Baseband Board (DBB) which implements the modem for all RRHs.
This new BTS architecture requires a high performance array of DSPs in order to process the compute intensive modems for HSPA, WiMAX and LTE. The high data throughput that these standards offer for Mobile Broadband on Smart Phones is very demanding for the DSP sub-system. However because of the remote architecture, DBBs will serve multiple RRH and be integrated in a low volume enclosure. Thus very large DSP performance needs to be integrated in a tight space with small power supplies and natural cooling. Power Consumption per Unit Work is therefore the key criteria for system and hardware architects when designing SDR BTS.
The following diagrams show how to build a high performance modem sub-system using multiple OCT2224W interconnect through SRIO to share Antenna samples distributed through a CPRI interface and using SGMII to communicate with a Control Processor responsible for the RNC interface or the LTE MAC interface.
The OCT2224W architecture has been designed to handle by software all known cellular standards. Modems are implemented mostly in software but use a few hardware accelerators that are highly programmable and can adapt to future cellular standards revisions and evolutions.
Octasic offers GSM-EDGE and WCDMA- HSPA Layer 1 Library in source code format, both optimized for the OCT2224W Opus2 DSP cores. These libraries can be used as is to build a complete BTS can be combined with the System Integrator’s proprietary algorithms.
Octasic offers a complete set of development tools for the OCT2200 Series of devices. Opus Studio, an Integrated Development Environment (IDE), provides the necessary tools for code editing, compiling, simulation, debugging, and profiling. Octasic also provides a real-time kernel and RTOS services upon which embedded applications can rapidly be developed.