Adaptive Power Allocation for Distributed Beamforming OSTBC Systems
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Solution Overview
Problem
Conventional distributed wireless communication systems using beamforming combined with orthogonal space-time block codes face challenges in optimal transmission power allocation due to varying large-scale fading from mobile terminals to geographically distributed antennas, leading to suboptimal performance and increased symbol error rates.
Innovation Solution
An adaptive transmission power allocation scheme is implemented, utilizing Nakagami fading parameters and large-scale fading information to optimize power distribution across geographically distributed antenna sub-arrays, selecting subsets with the best performance and applying power allocation based on these parameters to minimize symbol error rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If equal power allocation is used in distributed wireless communication systems, then device complexity is reduced, but symbol error rate increases due to unequal large-scale fading from mobile terminals to geographically distributed antennas
Solution Approach 1:
The patent applies local quality by allocating different power levels to different antenna sub-arrays based on their individual channel conditions. Specifically, the transmitter determines large-scale fading for each antenna sub-array and allocates power proportionally to the Nakagami fading parameter of each, rather than using uniform power allocation. This allows each part of the system (each antenna sub-array) to operate with optimized power levels matched to its local channel characteristics, thereby reducing symbol error rates while maintaining manageable complexity through structured power allocation rules.
2Reliability
If adaptive power allocation based on channel state information is implemented, then symbol error rate is reduced, but device complexity and processing requirements increase
Solution Approach 1:
The patent applies segmentation by dividing the antenna system into multiple geographically distributed antenna sub-arrays, each treated as an independent transmission unit with its own power allocation. The transmitter processes each sub-array separately, determining large-scale fading and allocating power independently for each. This segmentation allows the complex adaptive power allocation problem to be broken down into manageable sub-problems, reducing overall system complexity while maintaining the benefits of channel-adaptive power control.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the power allocation parameter (power proportional to Nakagami fading parameter) based on channel conditions. The system changes the power parameter for each antenna sub-array according to its specific fading characteristics, allowing adaptive optimization of transmission reliability without requiring complete redesign of the power allocation mechanism.
3Ease of manufacture
If conventional beamforming with orthogonal space-time block codes is used, then implementation simplicity is maintained, but transmission performance is suboptimal in scenarios with varying communication environments and fading models
Solution Approach 1:
The patent applies preliminary action by pre-determining the large-scale fading for each antenna sub-array before actual data transmission. The system calculates the Nakagami fading parameter and allocates power accordingly in advance, based on channel state information obtained through feedback or estimation. This preliminary power allocation based on predicted channel conditions allows the system to adapt to varying communication environments and fading models, improving transmission performance while maintaining implementation simplicity through structured pre-computation.
Data Source
AI summary
Disclosed is an apparatus and method for adaptively allocating transmission power for beamforming combined with orthogonal space-time block codes (OSTBC) in a distributed wireless communication system, the apparatus comprising: a plurality of sub-arrays for beamforming, which are geographically distributed and each of which comprises a plurality of distributed antennas placed in random groups; and a central processing unit for identifying performances of subsets by applying a predetermined power allocation scheme according to subsets which can be obtained by combining the sub-arrays, by means of a Nakagami fading parameter and information about large-scale fading of each of the sub-arrays, fed back from a receiving party, for determining a subset having a best performance as an optimal subset according to the identified performances, and for performing power allocation based on the subset set as the optimal subset.