Random Access Channel Timing Adjustment for Large Round Trip Times
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Solution Overview
Problem
Wireless communication systems face challenges in managing large round trip times during random access channel procedures, leading to processing errors and decoding issues due to timing differences that extend beyond sequence boundaries, especially in scenarios with significant distance between devices.
Innovation Solution
The implementation of a method where wireless devices transmit and receive messages with varying timing parameters based on energy metrics and sequence associations, allowing for accurate timing adjustments and retransmissions to ensure successful communication, even with large round trip times, by using cyclic prefixes and sets of sequences in random access channel procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional random access channel procedures are used with fixed timing parameters, then the procedure is simple to implement, but processing errors and decoding issues occur due to timing differences extending beyond sequence boundaries in large round trip time scenarios
Solution Approach 1:
The patent implements dynamic timing parameters that adapt to large round trip time conditions. The base station determines whether large RTT is detected and selectively applies different timing parameter sets (first timing parameter for normal conditions, second timing parameter for large RTT conditions). This dynamic adjustment allows the system to maintain decoding reliability by matching timing parameters to actual propagation conditions without requiring complex permanent configurations.
Solution Approach 2:
The patent changes timing parameters based on detected conditions. When large round trip time is detected, the system switches from using a first timing parameter (based on preamble sequence boundaries) to a second timing parameter (accounting for large propagation delay). This parameter change resolves the contradiction by adapting the timing structure to match actual channel conditions, preventing processing errors while maintaining procedural simplicity through conditional logic.
2Reliability
If timing parameters are adjusted to account for large round trip times, then communication reliability improves, but processing overhead increases due to additional timing parameter management
Solution Approach 1:
The patent segments the timing parameter management into distinct cases: normal timing parameters for standard conditions and large RTT timing parameters for extended delay conditions. By dividing the parameter space into manageable segments based on propagation delay characteristics, the system achieves reliable communication under varying conditions without requiring complex continuous adjustments, thus limiting processing overhead.
Solution Approach 2:
The base station detects whether large round trip time conditions exist and uses this feedback to select appropriate timing parameters. This feedback mechanism enables the system to automatically adapt to propagation conditions, improving communication reliability when needed while avoiding unnecessary processing overhead when standard timing parameters suffice. The feedback loop keeps timing parameter management efficient through condition-based decision making.
3Measurement precision
If multiple timing parameters are used for different sequences, then accurate timing adjustment is achieved, but device complexity increases due to multiple parameter sets
Solution Approach 1:
The patent applies different timing parameters to specific sequences based on their association with large or normal round trip times. Rather than using a single complex parameter set for all sequences, the system assigns first timing parameters to sequences associated with normal RTT and second timing parameters to sequences associated with large RTT. This local differentiation achieves precise timing adjustment for each sequence type while keeping the overall system manageable through targeted parameter application.
Solution Approach 2:
The patent creates a universal timing parameter framework where two parameter sets serve multiple functions: the first timing parameter handles normal operating conditions, while the second timing parameter handles large RTT conditions. Both parameter sets are part of a unified random access channel procedure that can adapt to different propagation scenarios, achieving versatile timing adjustment without requiring separate procedures for each condition.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A first wireless device may receive, from a second wireless device, a first message of a random access channel procedure. The first message may include a preamble having a cyclic prefix and a set of sequences. The first wireless device may transmit a second message of the random access channel procedure indicating a first timing parameter for subsequent communications between the devices. The first wireless device may transmit a third message to the second wireless device that indicates a second timing parameter. In some cases, the second wireless device may receive control signaling from the first wireless device indicating a timing offset for the first message of the random access channel procedure. The second wireless device may transmit the first message using the timing offset in response to receiving the control signaling.