Radio Receiver Buffer Switching for Clock Drift Alignment
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Solution Overview
Problem
Conventional radio receivers face timing misalignment issues due to drift between local and network clocks, leading to incorrect buffer switching and increased processor overhead, particularly in LTE networks, which affects the demodulation of data packets.
Innovation Solution
A radio receiver device with indexed memory buffers and a buffer switch pointer that adjusts timing dynamically to align local timing with network timing, using timing adjustment buffers to realign buffer switching points, reducing the need for pointer updates and intra-vector shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional radio receivers use fixed buffer switching based on local timing, then the device complexity is low, but timing misalignment occurs due to clock drift between local and network clocks
Solution Approach 1:
The buffer switching mechanism is made dynamic by allowing the trigger address to be adjusted based on detected timing offsets. Instead of a fixed buffer switching schedule, the system dynamically modifies the trigger address to compensate for clock drift between local and network clocks, ensuring timing alignment while managing complexity through controlled adaptability
Solution Approach 2:
The system changes the parameter of the trigger address in response to detected timing offsets. By modifying this key parameter based on timing measurements, the system maintains accurate timing alignment without requiring complete redesign of the buffer management architecture
2Reliability
If the trigger address is frequently updated to correct timing offsets, then timing alignment is maintained, but processor overhead increases
Solution Approach 1:
The system applies partial correction by adjusting the trigger address only to the extent necessary to compensate for measured timing offsets, rather than continuously or excessively updating it. This approach maintains timing synchronization while minimizing the processing overhead associated with frequent updates
3Adaptability or versatility
If multiple buffers are used to handle timing variations, then timing flexibility is improved, but memory requirements and device complexity increase
Solution Approach 1:
The existing buffer structure is made multi-functional by enabling it to handle both normal data storage and timing compensation through dynamic trigger address adjustment. This universal approach allows the same memory resources to serve multiple purposes without requiring additional dedicated buffers for timing variations
Data Source
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AI summary
A radio receiver device is arranged to store samples of incoming data symbols in an indexed memory portion having a length of A+B+C. A first data buffer 20-1 has an initial address at index 0 and a final address at index A-1. A timing adjustment buffer (22) has an initial address at index A and a final address at index A+B-1. A second data buffer 20-2 has an initial address at an index A+B and a final address at an index A+B+C-1. A buffer switch pointer (24) has a trigger address between the index 0 and the index A+B-1, at which it triggers a switch (26) from the first to the second buffer. If the current address matches the trigger address, the current address is set to the index A+B. Otherwise, the current address is incremented. If there is a timing offset between local and network clocks, the trigger address is moved to reduce the offset.