LTE-A Uplink Power Control Codeword-Specific Offset
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Solution Overview
Problem
In the LTE-A system, using a conventional power control method designed for single antenna and single codeword uplink transmission leads to excessive transmission power and early power shortages, increasing cell interference due to the use of multiple transmit antennas.
Innovation Solution
An uplink power control method for user equipment (UE) with multiple transmit antennas, where individual codewords are assigned specific transmit powers using transmit power control offset parameters to prevent excessive power increase and control cell interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional power control method designed for single antenna and single codeword is used in LTE-A system with multiple transmit antennas, then transmission power increases excessively, but cell interference increases and power shortages occur early
Solution Approach 1:
The patent segments the total transmission power into individual codeword-specific power allocations. Instead of applying a single power control parameter to all transmit antennas and codewords, the system divides power control into separate components for each codeword (P0,δ1 for first codeword, P0,δ2 for second codeword), allowing independent power management that prevents excessive total power while maintaining necessary signal levels for each data stream
Solution Approach 2:
The patent applies local quality by assigning different power control offset parameters (δ1, δ2) to different codewords based on their specific channel conditions, modulation and coding schemes, and interference levels. This localized power adjustment ensures that each codeword receives appropriate power according to its local requirements rather than applying uniform power control across all transmissions
2Productivity
If multiple transmit antennas are used to increase spectral efficiency, then transmission capacity improves, but transmission power increases excessively leading to power shortages
Solution Approach 1:
The patent segments power allocation across multiple codewords transmitted on multiple antennas, assigning specific power control parameters to each codeword. This segmentation allows the system to maintain high spectral efficiency through multiple simultaneous transmissions while preventing excessive total power consumption by individually managing power for each codeword based on its specific requirements
3Area of stationary object
If transmission power is increased to improve coverage, then coverage area expands, but cell interference increases
Solution Approach 1:
The patent applies local quality by adjusting power control offset parameters for each codeword based on specific channel conditions and interference levels. This allows the system to expand coverage area by transmitting at appropriate power levels for each local condition rather than uniformly increasing power across all transmissions, thereby expanding coverage while minimizing overall cell interference
Data Source
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AI summary
An LTE-A system and power control method for controlling cell interference based on codeword-specific transmission power adjustment with a transmission power control offset parameter. The method includes transmitting a parameter KS signaled by a higher layer and codeword-specific power control parameters from a base station to a terminal; calculating gains at the terminal, using the codeword-specific power control parameters and the parameter KS; calculating, at the terminal, codeword-specific transmit powers according to the gains; and transmitting, from the terminal to the base station, at least two codewords at the codeword-specific transmit powers.