Cooperative Scheduling for Interference Cancellation Efficiency
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Solution Overview
Problem
Existing interference cancellation receivers in HSDPA systems have low efficiency due to difficulties in decoding interfering signals from neighboring cells, particularly in scenarios involving macro and micro cells, where the efficiency of post-decoding and pre-decoding IC receivers is hindered by channel quality indicators and signal-to-noise ratios.
Innovation Solution
A method for coordinated scheduling based on interference cancellation, where user equipment generates and feeds back quality indicators, such as SNR or CQI, to base stations to select interfering UEs for scheduling, allowing for precise reconstruction of interfering signals and improved interference cancellation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If post-decoding interference cancellation is used, then interference cancellation can be performed, but the IC efficiency is low because the Victim IC UE cannot correctly decode the interfering signal when the SINR of the interfering UE is greater than the SINR of the Victim IC UE
Solution Approach 1:
The base station performs preliminary scheduling of the interfering UE before the Victim IC UE attempts to decode the interfering signal. By scheduling the interfering UE first and allocating resources, the base station ensures that the interfering signal can be correctly decoded by the Victim IC UE, which is essential for successful interference cancellation. This preliminary action resolves the timing and resource allocation issues that cause decoding failures.
Solution Approach 2:
The system changes scheduling parameters such as transport block size, modulation scheme, and resource allocation based on the SINR conditions of both the Victim IC UE and the interfering UE. When the interfering UE has high SINR, the base station adjusts its scheduling parameters to ensure the interfering signal remains decodable by the Victim IC UE, thereby improving interference cancellation efficiency while maintaining system throughput.
2Reliability
If pre-decoding interference cancellation is used, then interference cancellation can be performed, but the IC efficiency is low due to variations in modulation scheme and code channel quantity of interfering UE
Solution Approach 1:
The system implements feedback mechanisms where the base station receives channel quality indicators (CQI) and other channel state information from both the Victim IC UE and the interfering UE. This feedback enables the base station to adaptively adjust the modulation scheme and code channel quantity for the interfering UE, ensuring that the interfering signal can be properly processed for interference cancellation while maintaining optimal system performance.
Solution Approach 2:
The scheduling parameters for the interfering UE are made dynamic rather than fixed. The base station continuously adjusts modulation schemes, code channel quantities, and resource allocations based on real-time channel conditions and interference cancellation requirements. This dynamic adaptation allows the system to handle varying SINR conditions and maintain high interference cancellation efficiency across different scenarios.
3Productivity
If the base station schedules interfering UE with high CQI (near-field UE), then the transport block size is large, but this reduces the probability that the Victim IC UE can correctly decode the interfering signal
Solution Approach 1:
When the interfering UE has high CQI and would normally be allocated large transport blocks, the base station applies partial action by reducing the transport block size or adjusting the modulation scheme to a more robust level. This partial reduction ensures that the interfering signal remains decodable by the Victim IC UE while still maintaining reasonable system throughput. The base station schedules such interfering UEs in coordinated manner with the Victim IC UE to balance throughput and interference cancellation requirements.
Data Source
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AI summary
A method for coordinated scheduling based on interference cancellation, an apparatus, and a system are disclosed. The method includes: generating, by UE, a first quality indicator of a channel from an interfering cell of the UE to the UE; and feeding back, by the UE, the first quality indicator to a first base station to which the interfering cell belongs, and/or feeding back the first quality indicator to a second base station to which a serving cell of the UE belongs, to enable the first base station and/or the second base station to select, according to the first quality indicator, interfering UE that is to be scheduled together with the UE, schedule, in the serving cell of the UE, the UE, and simultaneously schedule, in a serving cell of the interfering UE, the interfering UE. The method for coordinated scheduling based on interference cancellation, the apparatus, and the system that are provided in embodiments of the present invention can improve the interference cancellation efficiency of an interference cancellation receiver.