Single Inner Power Control Loop for Uplink MIMO Pilot Signals
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Solution Overview
Problem
Current HSUPA systems do not allow MIMO transmission, and existing power control methods for uplink MIMO are inefficient, as they require multiple inner and outer loop power control loops, increasing signaling load and making it difficult to maintain radio link quality across multiple virtual antennas.
Innovation Solution
Implementing a single inner power control loop that adjusts the transmission power of multiple pilot signals, with a fixed power difference between them, and using a power offset to control the number of bits transmitted on each stream, allowing the network to control the quality of uplink MIMO transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple inner and outer loop power control loops are used for uplink MIMO transmissions, then the quality of transmission on each virtual antenna can be controlled, but the signaling load increases and the system complexity increases
Solution Approach 1:
The patent combines multiple power control loops (inner and outer loops for multiple virtual antennas) into a single power control mechanism. The network node controls the total transmission power across all virtual antennas using one power control loop, rather than maintaining separate loops for each antenna, thereby reducing signaling load and system complexity while still ensuring reliable transmission.
Solution Approach 2:
The single power control mechanism is designed to universally control power allocation across multiple virtual antennas simultaneously. It performs the function of what would otherwise require multiple specialized power control loops, adapting to different MIMO configurations and antenna numbers through a unified control approach.
2Reliability
If multiple inner and outer loop power control loops are used for uplink MIMO transmissions, then the quality of transmission on each virtual antenna can be controlled, but the signaling load increases
Solution Approach 1:
The patent merges multiple power control signaling channels into a single signaling mechanism. Instead of transmitting separate power control commands for each virtual antenna through multiple signaling channels, the network node uses a single power control loop that transmits unified power control instructions, thereby reducing the signaling load and information overhead.
3Device complexity
If fixed power difference is maintained between pilot signals on different streams, then power control is simplified, but flexibility in optimizing each stream's power is reduced
Solution Approach 1:
The patent implements a dynamic power allocation approach where the power difference between pilot signals on different streams is not fixed but can be adjusted based on channel conditions, stream importance, and quality requirements. The single power control loop dynamically determines optimal power distribution, maintaining simplicity while adapting to varying operational requirements.
Data Source
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AI summary
The disclosure relates to methods and apparatuses that facilitate power and quality control of uplink MIMO transmissions. A method in a NodeB comprises controlling (50) transmission power of multiple pilot signals transmitted by a user equipment by using a single inner power control loop operating on at least one pilot signal of the multiple pilot signals. Some disclosed embodiments also relate to adjustment (60) of a quality target applied by the single inner power control loop and to updating (71, 72) of a power offset for computing the number of bits that the user equipment can transmit on a stream that is associated with a pilot signal that is not power controlled by the single inner power control loop.