HSUPA Power Control via Dynamic SIR Target Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In High Speed Uplink Packet Access (HSUPA) systems, there is a challenge in optimizing power control to balance Signal-to-Interference Ratio (SIR) and Enhanced Dedicated Channel (E-DCH) power, leading to inefficiencies in uplink capacity and channel estimation, particularly at varying power levels and interference conditions.
Innovation Solution
A method and system for power control in HSUPA that adjusts the SIR target value and recalculates the Enhanced Dedicated Physical Data Channel (E-DPDCH) power based on changes in absolute grants, optimizing channel estimation and interference management by changing the SIR target and compensating power offsets when E-DPDCH grants exceed or fall below thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the SIR target value is increased to improve channel estimation quality, then the uplink capacity and data rate are improved, but the E-DCH power consumption increases and interference to other users increases
Solution Approach 1:
The patent applies dynamics by making the SIR target value adjustable rather than fixed. The base station dynamically changes the SIR target value based on the absolute grant level detected in the system. When absolute grant is high, a higher SIR target is used to improve channel estimation. When absolute grant is low, the SIR target is reduced to limit interference. This dynamic adaptation resolves the contradiction between achieving good channel estimation and controlling interference.
Solution Approach 2:
The patent changes the SIR target value parameter based on system conditions (absolute grant level). By adjusting this key parameter, the system optimizes the trade-off between channel estimation quality and interference generation. The base station monitors absolute grant and accordingly modifies the SIR target value, enabling the system to adapt to varying load conditions and user requirements.
2Reliability
If the DPCCH power is increased to improve control channel reliability, then the channel estimation is improved, but the overall E-DCH power consumption increases
Solution Approach 1:
The patent makes the SIR target value dynamic based on absolute grant detection. When absolute grant is high, the system can afford higher DPCCH power for improved reliability. When absolute grant is low, the SIR target is reduced, which consequently reduces DPCCH power requirements. This dynamic approach ensures control channel reliability is maintained only when system resources permit, optimizing overall power consumption.
Solution Approach 2:
By changing the SIR target value parameter according to absolute grant levels, the patent indirectly controls the DPCCH power requirements. The parameter change allows the system to adjust control channel power consumption based on available resources, resolving the contradiction between maintaining reliability and reducing energy use.
3Ease of operation
If the SIR target value is kept constant to simplify power control, then the implementation is easier, but the uplink capacity is not optimized under varying grant conditions
Solution Approach 1:
The patent introduces dynamics to the power control system by making the SIR target value adjustable based on detected absolute grant levels. This dynamic adaptation optimizes uplink capacity under varying grant conditions without significantly complicating the power control implementation. The base station simply monitors absolute grant and adjusts the SIR target accordingly, maintaining ease of operation while improving productivity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a method and an enhanced uplink (UL) telecommunication system for power control. The system comprises at least one first radio network controller (RNC) (12) and at least one first base station (11), which enables wireless communication with at least one first user terminal (15). The power for an uplink Dedicated Physical Control Channel (DPCCH) in a first enhanced UL transport channel (E-DCH) is controlled. The control is made by the first base station (11) on the basis of a signal to interference ratio (SIR) target value sent by the first RNC (12). Thereby, the SIR real time value for the UL DPCCH is controlled towards the target value. The first user terminal (15) and the first base station (11) further calculate a power for at least an Enhanced Dedicated Physical Data Channel (E- DPDCH) in the first E-DCH, which power is defined as the sum of the DPCCH power and a power offset. The calculation is at least based on a power offset configuration and an absolute grant provided by the first base station (11), which grant at least set the maximum E-DPDCH power. The first user terminal (15) further transmits the uplink data traffic on the first E-DCH with the controlled DPCCH power and the calculated E-DPDCH power. What particularly characterises the present invention is that when the first base station (11) and the first user terminal (15) detects that the E-DPDCH absolute grant is reduced below or increased above a grant threshold, the base station (11) changes the SIR target value. Further, the first base station (11) and the first user terminal (15) compensates the change of the target value by recalculating at least the E-DPDCH power so that the power reflects both the changed DPCCH power resulting from the changed SIR target value and the improvement due to optimized channel estimation in case of changed SIR real time value.