Adaptive Power Allocation for Distributed Wireless Sub-arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional distributed wireless communication systems using orthogonal space time block codes (OSTBC) and beam-forming face challenges in varying large-scale fading conditions and unequal power allocation, leading to suboptimal performance in actual systems with Nakagami fading channels.
Innovation Solution
An adaptive transmission power allocation method is introduced, where power is allocated based on large-scale fading information and Nakagami fading parameters, allowing for optimal subset selection and power distribution across geographically distributed sub-arrays to minimize outage probability and maximize capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If equal power allocation is used across distributed sub-arrays, then device complexity is reduced, but communication reliability deteriorates due to suboptimal performance in varying large-scale fading conditions
Solution Approach 1:
The patent changes the power allocation parameter from equal distribution to adaptive distribution based on large-scale fading information. The base station adjusts transmission power for each sub-array according to channel conditions, transforming the system from static equal power allocation to dynamic parameter-based power allocation, thereby improving communication reliability without excessive complexity increase
Solution Approach 2:
The patent implements a feedback mechanism where large-scale fading information is exchanged between the base station and mobile terminal. The mobile terminal measures channel conditions and feeds back fading information to the base station, which then uses this feedback to adaptively adjust power allocation, creating a closed-loop control system that improves reliability
2Reliability
If adaptive power allocation based on large-scale fading information is implemented, then communication reliability is improved, but device complexity increases due to additional information processing requirements
Solution Approach 1:
The patent applies local quality by treating each distributed sub-array differently based on its specific large-scale fading conditions. Instead of uniform processing, each sub-array receives customized power allocation according to its local channel characteristics, optimizing reliability for each location while managing overall system complexity
Solution Approach 2:
The patent uses partial action by selecting only the most significant fading parameters (large-scale fading) for power allocation decisions, ignoring less critical channel variations. This selective approach provides sufficient reliability improvement without requiring processing of all channel state information, thus controlling complexity
3Ease of operation
If conventional equal power allocation is used, then ease of operation is maintained, but system capacity is reduced due to inability to adapt to varying fading conditions
Solution Approach 1:
The patent transforms the static power allocation system into a dynamic one that adapts to changing fading conditions. The power allocation automatically adjusts in response to varying channel states, enabling the system to maintain ease of operation while significantly improving capacity through adaptive behavior
4Device complexity
If power is allocated without considering Nakagami fading parameters, then device complexity is minimized, but loss of information increases due to suboptimal power distribution
Solution Approach 1:
The patent incorporates Nakagami fading parameters as key variables in the power allocation decision process. By changing from ignoring fading parameters to explicitly using them, the system optimizes power distribution to minimize information loss while keeping the implementation complexity manageable through focused parameter usage
Data Source
AI summary
An apparatus that adaptively allocates transmission power for beam-forming combined with orthogonal space time block codes in a distributed wireless communication system, the apparatus including: sub-arrays for beam-forming, which are geographically distributed and each of which includes a plurality of distributed antennas placed in random groups. A central processing unit provides predetermined combinable power allocation schemes according to subsets in a plurality of the sub-arrays, identifying performances of the schemes by using information on large-scale fading of each of the sub-arrays fed back from a receiving party, setting a subset having best performance as an optimal subset according to the identified performances, and performing power allocation according thereto.