Sayram: A Hardware-software Co-design to Accelerate Wireless Baseband Processing

Abstract

Sayram is a novel hardware-software co-design specifically developed to accelerate the computationally intensive tasks within wireless baseband processing, crucial for high-speed 5G communications. By integrating highly specialized hardware accelerators with optimized software layers running on an extensible RISC-V platform, Sayram significantly improves throughput and energy efficiency. This architecture demonstrates the feasibility of using custom co-designed solutions to meet the demanding real-time requirements of next-generation base stations.

Report

Key Highlights

• Hardware-Software Co-Design: Sayram proposes a highly customized methodology where wireless baseband tasks are partitioned between specialized hardware modules and optimized software running on a central processing core.
• Acceleration Target: The design focuses on accelerating key bottlenecks in modern wireless standards, such as complex channel coding (e.g., LDPC decoding) and signal processing functions (e.g., FFT/iFFT).
• Performance Gains: The co-design architecture achieves substantial speedup and reduction in power consumption compared to purely software implementations or general-purpose processors, demonstrating real-time capability for high data rate processing.
• RISC-V Foundation: The system utilizes a RISC-V core as the primary control plane and host architecture, leveraging its open standard and extensibility for integration.

Technical Details

• Architecture: Sayram typically features a heterogeneous architecture where a RISC-V CPU manages control flow and scheduling, while multiple custom accelerator units handle compute-heavy kernels in parallel.
• Custom Instruction Set Extensions (ISEs): The implementation often incorporates RISC-V Custom Instructions to facilitate efficient communication, data marshalling, and synchronization between the host processor and the dedicated baseband accelerators, minimizing communication overhead.
• Software Optimization: The software layer includes optimized memory access patterns, precise task scheduling algorithms, and highly tuned data placement strategies to maximize accelerator utilization and minimize off-chip memory access.
• Efficiency Metric: The design emphasizes high throughput per watt, making it suitable for deployment in energy-conscious base station infrastructure (gNBs).

Implications

• Validation of RISC-V in Telecom: Sayram provides a strong proof point that the extensible RISC-V architecture is suitable not just for embedded systems, but also for highly demanding, domain-specific infrastructure like wireless base stations.
• Open Hardware for Critical Infrastructure: This work encourages the adoption of open and customizable hardware methodologies in the historically proprietary telecommunications market, fostering innovation and flexibility.
• Accelerating 5G/6G Adoption: By solving critical throughput and power challenges in baseband processing, Sayram enables more energy-efficient and scalable network deployments necessary to support the growing density and data demands of 5G and future 6G networks.
• Domain-Specific Customization: It serves as a prime example of how hardware-software co-design using RISC-V's inherent extensibility can create solutions that significantly outperform general-purpose platforms in specialized domains.