Multi-SIM Uplink Symbol Blanking for Interference Mitigation
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Solution Overview
Problem
Multi-SIM wireless devices face conflicts during simultaneous communications due to coexistence of RF resources, leading to issues like desense and timing collisions, with no convenient mechanism to determine if a base station can detect discontinuous transmission, affecting throughput and priority communication scheduling.
Innovation Solution
Implement a method in multi-SIM wireless communication devices to identify overlapping subframes and selectively blank symbols or subframes based on a blanking policy, determining whether to transmit partially blanked subframes considering control information, DMRS, user data, and modulation coding scheme, to minimize interference and maintain higher priority communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmit activity is performed on a modem stack associated with a first SIM, then data transmission throughput is improved, but interference is caused to higher priority communication on a modem stack associated with a second SIM
Solution Approach 1:
The patent segments the transmit activity into individual subframes and further into symbols within each subframe. By identifying specific overlapping subframes between LTE and GSM transmissions, the system can selectively blank only the conflicting symbols rather than entire subframes or complete transmissions, thereby maintaining throughput while eliminating interference.
Solution Approach 2:
The patent applies different blanking treatments to different parts of the transmission based on local conditions. Control information symbols are protected from blanking while data symbols may be blanked, and the decision is made symbol-by-symbol based on overlap with higher priority communications. This local differentiation allows selective interference mitigation without sacrificing overall transmission performance.
2Object-generated harmful factors
If symbol-level blanking is applied to mitigate interference, then interference reduction is achieved, but transmission efficiency is reduced due to loss of control information
Solution Approach 1:
The patent differentiates between control information symbols and data symbols, applying blanking selectively only to data symbols that overlap with higher priority communications. Control information symbols are always protected from blanking, ensuring transmission efficiency is maintained while still achieving interference reduction through selective blanking of non-critical data.
Solution Approach 2:
The system monitors transmission status and identifies when LTE uplink transmissions overlap with GSM higher priority communications. Based on this feedback, it dynamically adjusts blanking decisions for subsequent overlapping subframes, optimizing the balance between interference reduction and transmission efficiency through adaptive control.
3Object-generated harmful factors
If a blanking policy is implemented to manage uplink transmissions, then interference with higher priority communications is reduced, but device complexity increases due to subframe identification and policy enforcement
Solution Approach 1:
The patent establishes a predetermined blanking policy that defines the priority relationships between different communication types (e.g., GSM voice calls have higher priority than LTE data). This policy is configured in advance, allowing the device to automatically make blanking decisions without complex real-time analysis, thereby reducing device complexity while still achieving interference reduction.
Solution Approach 2:
The device autonomously monitors its own transmission status, identifies overlapping subframes, and applies blanking according to the pre-configured policy without requiring external control or complex coordination with the base station. This self-service approach simplifies the system by making the device independently capable of managing its own interference issues.
4Object-generated harmful factors
If LTE uplink blanking is performed without base station DTX detection capability, then interference mitigation is achieved, but throughput loss increases due to inability to differentiate DTX from link failure
Solution Approach 1:
The patent segments the transmission into subframes and symbols, allowing selective blanking of only the specific symbols that cause interference rather than entire subframes. This granular control enables the base station to receive some transmission data even when DTX detection is not available, reducing throughput loss while still achieving interference mitigation through partial blanking.
Solution Approach 2:
The system changes the transmission parameter by selectively muting specific symbols within subframes based on overlap detection, rather than completely stopping transmission. This parameter modification allows the base station to maintain synchronization and continue processing received data, improving throughput while still mitigating interference through controlled blanking.
Data Source
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AI summary
Methods and devices are disclosed for enabling improved performance on a multi-subscriber identification module (multi-SIM) wireless communication device. The wireless communication device may detect transmit activity on a modem stack associated with the first SIM, and detect a communication activity scheduled on a modem stack associated with the second SIM having a higher priority. If the transmit activity on the modem stack of the first SIM will impede the communication activity, the wireless device may identify subframes on the modem stack associated with the first SIM that overlap in time with the communication activity and for each identified subframe, blank symbols that conflict with the communication activity to develop a partially blanked subframe. The partially blanked subframe may be transmitted according to a blanking policy.