MBSFN Subframe Configuration for Unicast Transmission Efficiency
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Solution Overview
Problem
Existing wireless communication systems face inefficiencies in utilizing Multimedia Broadcast/Multicast Services over Single Frequency Network (MBSFN) subframes for unicast transmissions, as reserved MBSFN subframes often remain unused due to rate variations, leading to underutilization of system resources.
Innovation Solution
Configuring MBSFN subframes for unicast transmissions by determining a pattern for reference signals based on non-MBSFN subframe patterns, allowing for efficient reuse of unused MBSFN subframes, and optimizing cyclic prefix and subframe/carrier bundling for hybrid automatic repeat request (HARQ) feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MBSFN subframes are reserved for broadcast/multicast services, then reliability of MBMS delivery is improved, but system resource utilization deteriorates when unicast traffic demands increase
Solution Approach 1:
The patent implements dynamic subframe configuration where MBSFN subframes can be flexibly allocated between broadcast/multicast and unicast services based on real-time traffic demands. The base station determines whether to transmit MBMS data or unicast data in each MBSFN subframe, allowing the system to adapt resource allocation dynamically rather than being statically assigned.
Solution Approach 2:
The patent makes MBSFN subframes multi-functional by enabling them to serve both traditional MBMS broadcast/multicast purposes and unicast transmissions. By introducing unicast-specific reference signals and appropriate patterns into MBSFN subframes, the same physical subframes can support multiple service types, increasing overall system efficiency.
2Productivity
If MBSFN subframes are used for unicast transmissions, then system resource efficiency is improved, but measurement precision of reference signals deteriorates without proper RS patterns
Solution Approach 1:
The patent applies different reference signal patterns tailored to specific subframe types. For MBSFN subframes used for unicast, a specific RS pattern is defined that places reference signals at positions optimized for unicast channel estimation. This local customization of RS patterns ensures measurement precision is maintained for each service type while allowing flexible resource allocation.
Solution Approach 2:
The patent changes the reference signal configuration parameters when MBSFN subframes are repurposed for unicast. By adjusting the RS pattern, density, and positioning parameters specifically for unicast transmissions in MBSFN subframes, the system maintains accurate channel estimation and measurement precision while improving overall resource utilization.
3Productivity
If cyclic prefix duration is reduced to improve throughput, then system throughput is improved, but reliability of signal transmission deteriorates in multipath environments
Solution Approach 1:
The patent implements dynamic cyclic prefix selection where the CP duration can be adapted based on channel conditions and service requirements. Different CP lengths can be configured for different subframes or user groups, allowing the system to optimize between throughput and reliability by selecting appropriate CP durations rather than using a fixed conservative value for all transmissions.
Data Source
AI summary
Certain aspects of the present disclosure propose methods and apparatus for utilizing unused Multimedia Broadcast over a Single Frequency Network (MBSFN) subframes for unicast transmissions. The proposed methods include efficient cyclic prefix (CP) and MBSFN frame structure design, and an optimized subframe/carrier bundling window design for hybrid automatic repeat request (HARQ) feedback in presence of the MBSFN subframes.