Extended Cyclic Prefix for MBSFN Signal Capture
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Solution Overview
Problem
Current wireless communication systems, particularly in LTE and MBSFN transmission structures, face inefficiencies due to insufficient cyclic prefix lengths, leading to reduced MBSFN gain as usable signals with longer propagation delays are misinterpreted as noise, especially in larger cell sizes.
Innovation Solution
Implementing an extended MBMS cyclic prefix length of at least 33.33 µs in MBSFN transmission structures to accommodate signals with longer propagation delays, allowing them to be combined effectively at the receiver and improving MBSFN gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard cyclic prefix length is used in MBSFN transmission, then the system can maintain compatibility with existing LTE structures, but signals with longer propagation delays appear as noise resulting in lower MBSFN gain
Solution Approach 1:
The patent applies parameter changes by extending the cyclic prefix length from the standard value to at least 33.33 µs. This parameter modification allows the extended cyclic prefix to cover the propagation delay of signals from cells at the edge of the MBSFN area, enabling these delayed signals to be combined constructively at the receiver instead of appearing as noise, thereby improving MBSFN gain in large cell scenarios
2Reliability
If an extended cyclic prefix length of at least 33.33 µs is used, then signals with longer propagation delays can be captured and combined effectively, but the subframe duration increases reducing transmission efficiency
Solution Approach 1:
The patent applies local quality by extending the cyclic prefix length specifically for MBSFN subframes while keeping unicast subframes unchanged. This localized modification ensures that only the subframes requiring extended delay coverage (MBSFN subframes in large cells) use the longer prefix, minimizing the impact on overall system transmission efficiency while improving signal capture capability where needed
3Adaptability or versatility
If the MBSFN cyclic prefix length is extended to at least 33.33 µs, then larger cell sizes can be supported with improved signal combination, but the subframe structure becomes more complex
Solution Approach 1:
The patent applies dynamics by making the cyclic prefix length configurable and adaptable to different deployment scenarios. The system can dynamically select between standard and extended cyclic prefix lengths based on cell size requirements, allowing flexible adaptation to both small and large cell deployments without being locked into a fixed structure
Data Source
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AI summary
A method, an apparatus, and a computer program product are provided for receiving unicast and multicast-broadcast single frequency network (MBSFN) signals from an eNB in a subframe. The apparatus receives at least one transmission in the subframe, the subframe divided into six partitions and for receiving at least one unicast symbol and a plurality of multicast-broadcast single frequency network (MBSFN) symbols, each of the at least one unicast symbol and the plurality of MBSFN symbols having an associated cyclic prefix (CP). The apparatus further receives at least one unicast signal including the at least one unicast symbol at a first partition of the subframe, and receives at least one MBSFN signal including the plurality of MBSFN symbols respectively at a second partition through sixth partition of the subframe, each MBSFN symbol having the associated CP with a length of at least 33.33 µs.