PRACH RO Bundle Frequency Hopping for Coherent Preamble Detection
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Solution Overview
Problem
Existing methods for improving preamble detection performance in wireless communication by frequency hopping result in poor coherent combination effects and deteriorated detection performance due to varying channels and phase jumps across different ROs in an RO group.
Innovation Solution
A method that combines frequency hopping with coherent detection by grouping ROs into bundles based on time-frequency positions, allowing coherent combination within bundles and frequency hopping between bundles to enhance detection success probability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency hopping is performed across multiple ROs in an RO group, then frequency diversity gain is obtained and preamble transmission reliability is improved, but coherent combination effects deteriorate due to varying channels and phase jumps
Solution Approach 1:
The RO group is segmented into multiple RO bundles, where each bundle contains ROs at the same frequency position. Frequency hopping is performed at the bundle level rather than individual RO level. This segmentation allows coherent combination within each bundle (maintaining measurement precision) while still achieving frequency diversity across different bundles (improving reliability).
Solution Approach 2:
Different RO bundles are assigned different frequency positions through frequency hopping, creating local quality variations. Within each local bundle, the channel conditions are similar enough for coherent combination, while globally across bundles, frequency diversity is achieved. This local quality approach resolves the contradiction between coherent detection and frequency diversity.
2Adaptability or versatility
If preambles are transmitted on multiple ROs at different frequency positions, then frequency diversity is achieved, but coherent combination of received preamble sequences becomes difficult due to different channels and phase jumps
Solution Approach 1:
By segmenting the transmission into RO bundles at the same frequency position, the patent simplifies coherent combination within each bundle while maintaining frequency diversity across bundles. This segmentation reduces the complexity of coherent combination compared to processing all ROs individually across different frequencies.
Solution Approach 2:
The RO bundle acts as an intermediary structure between individual ROs and the entire RO group. It provides a intermediate level of organization that enables coherent combination within the bundle while facilitating frequency hopping across bundles, thus reducing overall system complexity.
Data Source
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AI summary
A transmission method and a communication apparatus are provided. The transmission method includes: receiving an SSB and PRACH resource configuration information; determining time-frequency positions of a plurality of ROs in an RO group based on the SSB, the PRACH resource configuration information, and an RO frequency hopping manner in the RO group, where the RO group includes a plurality of ROs in time domain, and the plurality of ROs in the RO group correspond to different time domain positions; and the RO frequency hopping manner in the RO group includes: performing no frequency hopping on ROs belonging to a same slot in the RO group, or performing frequency hopping on ROs not belonging to a same slot using a frequency hopping step; or performing no frequency hopping on ROs belonging to a plurality of adjacent slots in the RO group, or performing frequency hopping on ROs not belonging to a plurality of adjacent slots using a frequency hopping step; and sending a preamble (preamble) separately on the plurality of ROs included in the RO group based on the time-frequency positions of the plurality of ROs in the RO group.