Dual HARQ Softbit Storage for OCM Space and Data Integrity
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Solution Overview
Problem
Conventional dynamic HARQ buffer management overwrites valid HARQ data, leading to reduced data rates and increased retransmission failures due to insufficient memory in On-Chip Memory (OCM), especially under critical channel conditions.
Innovation Solution
A method and device utilizing a dual storage system, where a first storage (On-Chip Memory) and a second storage (SDRAM) are dynamically allocated for HARQ segments, with a Soft HARQ Buffer Manager controlling the transfer of softbits between them to optimize memory usage and maintain valid data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the HARQ buffer is implemented in On Chip Memory (OCM) for fast data access, then the data access speed is improved, but the chip space consumption and cost increase significantly
Solution Approach 1:
The HARQ buffer is segmented into two parts: a first buffer in OCM for fast access and a second buffer in SDRAM for bulk storage. This segmentation allows the system to maintain fast access for actively used data while storing less frequently accessed data in external memory, thereby reducing overall chip space requirements while preserving data access speed for critical operations.
Solution Approach 2:
A buffer manager is introduced as an intermediary component that dynamically manages data transfer between the OCM buffer and SDRAM buffer. This mediator optimizes the distribution of data between the two storage media, ensuring that frequently accessed HARQ data remains in the fast OCM while minimizing the use of expensive on-chip memory resources.
2Area of stationary object
If dynamic HARQ buffer management is used to reduce OCM usage, then chip space is reduced, but valid HARQ data is overwritten leading to reduced data rates
Solution Approach 1:
The system dynamically adjusts the allocation of buffer space between OCM and SDRAM based on real-time HARQ process requirements and channel conditions. The buffer manager continuously monitors the state of HARQ processes and dynamically transfers data between buffers, ensuring that valid data is preserved while optimizing memory utilization and maintaining high data rates even under critical channel conditions.
Solution Approach 2:
The buffer manager changes the operational parameters of the HARQ buffer system by dynamically adjusting which data resides in which buffer based on priority, age, and retransmission status. This parameter optimization ensures that critical HARQ data is protected from overwriting while efficiently utilizing available memory resources, thereby maintaining data rates without requiring excessive chip space.
3Reliability
If a large HARQ buffer is allocated to store softbits for multiple parallel HARQ processes, then the reliability of data transmission is improved, but the memory resource consumption increases
Solution Approach 1:
The large HARQ buffer requirement is segmented across two memory technologies: OCM and SDRAM. The OCM portion stores softbits for currently active HARQ processes requiring fast access, while the SDRAM portion stores softbits for inactive or less critical processes. This segmentation maintains the total buffer capacity needed for reliable multi-process HARQ operation while reducing the amount of expensive on-chip memory required.
Solution Approach 2:
The dual-buffer system provides universal storage capability for all HARQ processes, with the buffer manager intelligently allocating space based on process priority and state. This multi-functional memory system serves both fast-access requirements and bulk storage needs, ensuring reliable data transmission across multiple parallel HARQ processes while optimizing overall memory resource utilization.
Data Source
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AI summary
A technique for storing softbits of messages received according to a Hybrid Automatic Repeat Request (HARQ) protocol is disclosed. As to a method aspect of the technique, a first storage (102) and a second storage (104) are provided. The first storage and a second storage include a plurality of memory segments (103) allocatable to HARQ processes. A first message related to a first HARQ process is received. The first message is protected by a channel code of the HARQ protocol and represented by softbits. The softbits of the first message are stored in a first segment of the first storage. The first segment is allocated to the first HARQ process. The first storage is accessible by a channel decoding unit (110) for decoding the channel code. If a number of allocated segments in the first storage, the decoding of which has not been yet completed, exceeds a threshold, the allocation for the first HARQ process is changed from the first segment in the first storage to a second segment in the second storage.