Preamble PN Code Allocation for PAPR Reduction in Multi-FA Systems
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Solution Overview
Problem
In broadband wireless communication systems using multiple Frequency Allocations (FAs) amplified by one power amplifier, existing methods fail to allocate distinct preamble Pseudo Noise (PN) codes to each FA without increasing Peak-to-Average Power Ratio (PAPR) and material costs, while maintaining performance similar to systems using single FAs.
Innovation Solution
The method involves defining an inherent index for each FA, allocating a preamble PN index using a reference FA index, and shifting these indices by a defined offset for remaining FAs, ensuring unique PN codes for each FA within a base station, thus minimizing PAPR and replication errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If identical preamble PN index is allocated to all FAs in a base station, then device complexity is reduced, but PAPR increases significantly when using MCPA
Solution Approach 1:
The patent applies local quality by allocating different preamble PN indexes to different FAs within the same base station. Specifically, the first FA uses a first preamble PN index while the second FA uses a second preamble PN index, allowing each FA to have optimized local characteristics rather than forcing global uniformity. This resolves the contradiction by permitting increased allocation complexity at the local FA level to achieve reduced PAPR at the system level.
2Use of energy by moving object
If different preamble PN indexes are allocated to multiple FAs, then PAPR is reduced, but the allocation method becomes more complex
Solution Approach 1:
The patent segments the preamble PN index allocation process into distinct components: a first preamble PN index allocated to the first FA and a second preamble PN index allocated to the second FA. This segmentation allows independent optimization of each FA's allocation while maintaining overall system coordination, thereby managing complexity through structured division rather than monolithic allocation.
Solution Approach 2:
The patent introduces an additional dimension to the allocation problem by considering both FA identity and preamble PN index as varying parameters. Instead of a single-dimensional allocation (one PN index for all FAs), the system operates in a two-dimensional space where each FA-PN index pair can be independently configured, enabling PAPR reduction through coordinated multi-dimensional allocation.
3Quantity of substance
If one MCPA is used to amplify multiple FAs, then material cost is reduced, but PAPR increases when identical preamble PN codes are used
Solution Approach 1:
The patent applies local quality by enabling each FA amplified by the shared MCPA to use a distinct preamble PN index. The first FA uses a first preamble PN index while the second FA uses a second preamble PN index, creating local differentiation that prevents constructive interference and reduces PAPR. This allows cost-effective MCPA sharing while maintaining signal quality through localized code differentiation.
4Ease of operation
If identical preamble PN index is allocated to adjacent base stations, then allocation simplicity is maintained, but terminal cannot perform initial search
Solution Approach 1:
The patent segments the preamble PN index space by allocating specific indexes to specific FAs within base stations. This segmentation ensures that adjacent base stations using the same frequency can assign different preamble PN indexes to their respective FAs, providing terminal search capability while maintaining systematic allocation simplicity through defined allocation rules.
Data Source
AI summary
An apparatus and a method for preamble pseudo noise code allocation in a broadband wireless communication system are provided. The method includes defining an inherent index for each FA, allocating a preamble PN index to base stations using a reference FA index, defining an inherent offset by each FA for remaining FA indexes, and shifting the preamble PN index allocated to the base stations using the reference FA index by the defined offset, and allocating the preamble PN index to base stations using the remaining FA indexes. The price of a system can thus be lowered by reducing a Peak-to-Average Power Ratio (PAPR) of a preamble, increase the number of FAs that a specific amplifier can amplify, and immediately allocate a preamble PN index when adding a new FA during an operation of a system.