Symbol Processing With Variable Cyclic Prefix Extensions
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Solution Overview
Problem
Existing communication technologies face challenges in flexibly configuring inter-symbol guard periods due to varying user channel conditions, leading to inefficient use of cyclic prefixes and increased overheads for users with different delay spreads.
Innovation Solution
The method involves mapping unique word sequences to transmit symbols to extend the cyclic prefix flexibly, allowing for different guard period lengths based on user requirements, thereby maintaining frame structure integrity and enabling multiplexing between users with diverse channel conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a fixed cyclic prefix length is used to maintain stable frame structure, then frame structure stability is improved, but flexibility to adapt to different user channel conditions is worsened
Solution Approach 1:
The cyclic prefix is segmented into a fixed-length base portion and a variable-length extension portion. The base portion maintains frame structure stability, while the extension portion can be adjusted based on user channel conditions (delay spread) to provide flexibility. This segmentation allows the system to simultaneously achieve structural stability and adaptive flexibility.
Solution Approach 2:
The cyclic prefix transitions from a static fixed-length structure to a dynamic structure where the length can be adjusted based on user requirements. The system dynamically determines the extension portion length according to channel conditions, enabling flexible adaptation while maintaining the stable frame structure through the fixed base portion.
2Reliability
If a long cyclic prefix is selected to ensure performance for long-delay-spread users, then reliability for long-delay users is improved, but overhead is increased for short-delay-spread users
Solution Approach 1:
Different portions of the cyclic prefix serve different functions: the fixed base portion ensures minimum protection for all users, while the variable extension portion provides additional protection only when needed based on local channel conditions. This local quality approach allows long-delay users to benefit from extended protection without forcing all users to tolerate unnecessary overhead.
Solution Approach 2:
The system changes the cyclic prefix length parameter dynamically based on user channel conditions. Instead of using a fixed long prefix for all users, the system adjusts the extension portion length according to each user's delay spread characteristics, optimizing the balance between reliability and overhead for different user types.
3Device complexity
If a fixed cyclic prefix length is used for all users, then device complexity is reduced, but flexibility to configure different guard periods is worsened
Solution Approach 1:
The cyclic prefix is divided into a fixed base portion and a variable extension portion. This segmentation allows the system to maintain simple fixed-length processing for the base portion while adding flexibility through the extension portion, achieving guard period configuration flexibility without significantly increasing overall device complexity.
Solution Approach 2:
The extension portion acts as an intermediary element that bridges the fixed base portion and the variable guard period requirements. This intermediary structure enables flexible guard period configuration by combining the simplicity of fixed processing with the adaptability of variable length through a unified cyclic prefix structure.
Data Source
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AI summary
This application provides a symbol processing method and an apparatus. The method includes: dividing a plurality of obtained complex-valued symbols into a plurality of sets, where each set corresponds to one transmit symbol, and the plurality of sets include a first set corresponding to a first transmit symbol; and mapping a first sequence and a second sequence to the first set, where an end position of the first sequence is a position of intercepting a cyclic prefix CP in the first transmit symbol, and an end position of the second sequence is an end position of the first transmit symbol. By mapping the sequence to the set, an original cyclic prefix CP can be extended by using a sequence with a flexible length, and flexible guard periods of different lengths can be configured for all users by adjusting the length of the sequence.