Downlink Power Ratio Control for PDSCH Demodulation
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently allocating downlink transmission power for OFDM systems, particularly in maintaining a power ratio between data and reference signals, which affects data demodulation accuracy and system throughput.
Innovation Solution
A method and apparatus for controlling downlink transmission power in a wireless communication system, where the base station determines and allocates a predefined power ratio between data transmission power and reference signal transmission power per resource element, ensuring consistent power allocation within an OFDM symbol, allowing accurate demodulation by user equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the base station dynamically adjusts transmit power per subcarrier to maximize throughput, then system throughput is improved, but the complexity of power allocation and UE demodulation calculation increases
Solution Approach 1:
The patent changes the parameter representation from absolute power values to power ratios. By defining a fixed power ratio between PDSCH and RS, the system maintains flexibility in power allocation while simplifying the parameters that need to be signaled and processed. This allows the base station to adjust overall power levels dynamically while keeping the relative distribution simple and predictable.
Solution Approach 2:
The patent uses reference signals as a copy or template for power allocation. By defining power relationships relative to RS power, the system creates a reference framework that simplifies power management. The UE can estimate channel conditions using RS and apply the known power ratio to determine PDSCH power, eliminating the need for complex absolute power calculations.
2Productivity
If the base station allocates different power levels for data and reference signals, then data transmission efficiency is improved, but the UE's ability to accurately determine power ratio for demodulation deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the base station signals the power ratio parameter to the UE. This explicit feedback ensures that the UE has accurate information about the power relationship between PDSCH and RS, enabling precise demodulation. The system maintains different power levels for efficiency while ensuring the UE knows the exact ratio through signaling.
3Area of stationary object
If the base station uses maximum available transmit power for downlink transmission, then system coverage is improved, but the power allocation flexibility for different users and channels is reduced
Solution Approach 1:
The patent introduces dynamic power allocation through the power ratio parameter that can be adjusted based on transmission conditions. The base station can change the power ratio between PDSCH and RS depending on the number of layers, channel conditions, and user requirements. This dynamic adjustment maintains maximum coverage while providing flexibility for different transmission scenarios.
Data Source
AI summary
A ratio of data transmission power of a layer per RE to RS transmission power of the layer per RE is predefined according to rank. A BS determines downlink transmission power for a PDSCH according to the predefined rank and a UE assumes that the PDSCH and UE-specific RS(s) for the PDSCH is transmitted with power satisfying the ratio.