OFDM Transmission Device Guard Interval Multiplexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing OFDM-based communication systems face challenges in efficiently transmitting channels with different guard interval lengths, particularly in varying propagation delay environments, which affects communication quality and efficiency.
Innovation Solution
A transmission device that time-division-multiplexes unicast and multicast/broadcast channels in the same frequency band, with a longer guard interval for multicast/broadcast channels to improve signal quality and efficiency, while using adaptive modulation and coding to optimize data transmission based on channel conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the guard interval length is increased to accommodate large propagation delays in multicast/broadcast channels, then signal quality and path diversity gain are improved, but information transmission efficiency deteriorates
Solution Approach 1:
The transmission time interval is divided into multiple subframes, with each subframe dedicated to a specific channel type (unicast or multicast/broadcast). This segmentation allows different guard interval lengths to be applied to different channels simultaneously, resolving the contradiction between signal quality and transmission efficiency.
Solution Approach 2:
Different guard interval lengths are applied locally to different channel types within the same transmission system. Multicast/broadcast channels use longer guard intervals for improved signal quality, while unicast channels use shorter guard intervals for higher transmission efficiency, allowing each channel to have optimized parameters suited to its specific requirements.
2Adaptability or versatility
If multiple groups of radio parameters with various guard interval lengths are prepared to adapt to different communication environments, then adaptability is improved, but device complexity and processing workload increase
Solution Approach 1:
The system segments channel types into distinct categories (unicast and multicast/broadcast) and assigns specific guard interval lengths to each category. This segmentation simplifies the parameter selection process compared to managing multiple groups of radio parameters, as the base station only needs to select between predefined channel types rather than configuring multiple parameter sets.
Solution Approach 2:
The transmission device uses a universal time-division multiplexing framework that can handle different channel types with different guard interval lengths through a single standardized mechanism. This multi-functional approach allows the system to adapt to various communication environments without requiring complex parameter configuration for each environment type.
3Area of stationary object
If time-division multiplexing is used to transmit unicast and multicast/broadcast channels in the same frequency band, then frequency band utilization is improved, but processing complexity increases
Solution Approach 1:
The transmission time interval is segmented into multiple subframes, with each subframe dedicated to a specific channel type. This temporal segmentation allows the system to multiplex unicast and multicast/broadcast channels in the same frequency band without interference, while the standardized subframe structure simplifies the multiplexing processing requirements.
Data Source
AI summary
A disclosed OFDM-based transmission device includes a unicast channel generating unit configured to generate a unicast channel; an MBMS channel generating unit configured to generate an MBMS channel; a multiplexing unit configured to time-division-multiplex the unicast channel and the MBMS channel in the same frequency band; and a transmitting unit configured to transmit time-division-multiplexed transmission symbols. In the disclosed transmission device, the guard interval length for the MBMS channel is set longer than the guard interval length for the unicast channel.