TD-SCDMA Broadcast Multicast Signal Frame Structure
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Solution Overview
Problem
The existing TD-SCDMA system fails to efficiently achieve macro cell coverage and macro diversity combining for Broadcast/Multicast Services due to limitations in channel estimation and Guard Period configurations, leading to interference and reduced system performance.
Innovation Solution
A signal frame structure is introduced where the channel estimation code is positioned before data symbols, and its extension cycle window is used as a Guard Period, allowing for extended multipath reception and increased transmission power, while maintaining the length of the time slot and data block unchanged, to support macro diversity and cell coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the channel estimation code length is increased to extend the extension cycle window for macro diversity reception, then the multipath reception capability is improved, but the Guard Period becomes insufficient and interference between time slots increases
Solution Approach 1:
The channel estimation code is segmented into two functional parts: a basic channel estimation code for channel estimation purposes, and an extension cycle window that functions as the Guard Period. This segmentation allows the extension cycle window to be extended for macro diversity reception while the basic channel estimation code maintains its estimation function, resolving the conflict between extended multipath reception and Guard Period sufficiency.
Solution Approach 2:
The extension cycle window of the channel estimation code is given dual functionality: it serves both as part of the channel estimation structure and as the Guard Period for preventing inter-time slot interference. This multi-functionality allows a single structure to fulfill multiple roles that previously required separate allocations, enabling macro diversity reception without compromising Guard Period effectiveness.
2Area of stationary object
If transmission power is increased to achieve macro cell coverage, then the coverage area is expanded, but interference between adjacent cells increases
Solution Approach 1:
The extended extension cycle window acts as a preliminary protective measure by providing sufficient Guard Period before adjacent time slots begin transmission. This preliminary action prevents inter-symbol interference from high-power transmissions, enabling macro cell coverage to be achieved without the interference that would normally result from increased transmission power.
3Reliability
If the extension cycle window is extended for macro diversity reception, then the reception quality is improved, but the time slot structure becomes constrained
Solution Approach 1:
The extension cycle window is designed to serve dual purposes: it provides the extended multipath reception capability needed for macro diversity while simultaneously functioning as the Guard Period. This multi-functionality allows reception quality to be improved without adding separate structures, thereby avoiding constraints on the time slot structure.
Data Source
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AI summary
A method and system for transmitting the broadcast/multicast service can solve the problem that the large range coverage of the broadcast/multicast service and the macro-diversity combination of multi-cells can not be implemented efficiently based on the frame structure of the existing Time Division-Synchronous Code Division Multiple Access TD-SCDMA system in prior art, the method includes: mapping the channel estimation code and the data symbol of the broadcast/multicast service into the resource unit, wherein the channel estimation code is mapped in front of the data symbol in the signal frames of all service slots or the broadcast/multicast service slots; and transmitting the resource unit. Using the application, the transmission efficiency and performance can be improved, and the multi-cells combination of broadcast/multicast service and deployment of multi-cells mechanism broadcast/multicast service can be implemented efficiently.