Inter-cell interference cancellation via signal re-encoding
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Solution Overview
Problem
Wireless networks face interference challenges due to disparate signal strengths between forward and reverse links in cellular networks, particularly in heterogeneous deployments and restricted association scenarios, which degrade data transmission performance.
Innovation Solution
The method involves encoding interfering channels with identifiers and adjusting transmission parameters to enhance the signal-to-interference noise ratio (SINR) for effective interference cancellation, allowing user equipment (UE) to decode and re-encode signals, thereby canceling out interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heterogeneous deployment with different base station powers is implemented, then network coverage and capacity are improved, but inter-cell interference increases
Solution Approach 1:
The patent converts the harmful interference from high-powered macrocells into useful information by having the interfering base station transmit its identifier and encode its signals. The victim UE uses this information to decode and re-encode the interfering signal, then subtract it from the received signal to cancel the interference. This transforms the harmful interference into a beneficial cancellation process.
Solution Approach 2:
The interfering base station performs preliminary actions by transmitting its identifier and encoding its signals in advance, before the interference cancellation process at the UE. This allows the UE to have the necessary information ready to perform accurate interference cancellation, improving the effectiveness of the interference mitigation.
2Reliability
If restricted association is implemented, then network security and quality of service are improved, but user equipment experiences higher interference
Solution Approach 1:
In restricted association scenarios, the UE is forced to connect to a weaker cell while a stronger interfering cell transmits. The patent converts this harmful situation into a benefit by enabling the UE to decode the interfering cell's signals using transmitted identifiers and perform interference cancellation, thereby improving the UE's ability to communicate reliably on its assigned resources.
3Measurement precision
If interference cancellation processing is performed, then signal quality is improved, but computational complexity increases
Solution Approach 1:
The UE creates a copy of the interfering signal by decoding it using the transmitted identifier and re-encoding it with the same identifier. This copied version of the interfering signal is then subtracted from the received signal to cancel the interference. The copying approach allows for accurate interference reproduction without requiring complex adaptive filtering.
Data Source
AI summary
Communication techniques enable efficient communication to an UE (User Equipment) that is subject to a dominant interference signal that is transmitted by a different base station. Disclosed interference cancellation techniques, both UE-centric and network-centric, are suitable to this situation. These techniques are particularly advantageous when undesirable or difficult to introduce changes in the physical (PHY) and medium access control (MAC) layers at the existing base stations. UE-centric framework refers to an approach largely implemented by UEs to include pico or femto cells. Network-centric framework closed-loop coordination between base stations and UEs mitigate interference thereby improving network performance. In particular, an interfering base-station can help a “victim” UE by adjusting downlink pilot and control power and to adjust traffic data rates responsive to information that the “victim” UEs provide, including information about the interfering link and performance of the cancellation itself sent over the air or using the backhaul.