Broadcast Link Adaptation via Signal Quality Threshold Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Broadcast-type wireless communications face challenges due to limited transmission capacity, high packet transmission fees, and varying signal quality among receivers, making it difficult to select optimal modulation and coding orders for multicast services.
Innovation Solution
A method and system for link adaptation where base stations determine a signal quality threshold, broadcast it to subscribers, and collect feedback on signal quality indicators to estimate the percentage of subscribers receiving signals above the threshold, allowing for adaptive selection of transmission modulation formats and coding based on this data, while minimizing uplink bandwidth usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If broadcast systems use high data rates for multicast transmission, then transmission capacity is improved, but signal quality varies greatly among receivers causing poor reception at cell edges
Solution Approach 1:
The patent applies local quality by enabling different modulation and coding schemes (MCS) for different receiver groups based on their individual signal conditions. Instead of using a single uniform transmission parameter for all receivers, the system determines appropriate MCS parameters tailored to each receiver's signal quality, allowing high data rates for receivers with good signal conditions while maintaining acceptable performance for those at cell edges.
Solution Approach 2:
The system dynamically adapts the modulation and coding scheme parameters based on real-time signal quality measurements from receivers. The base station continuously monitors signal conditions and adjusts transmission parameters accordingly, transitioning between different MCS configurations to optimize both transmission capacity and signal quality reliability across varying network conditions.
2Measurement precision
If the system collects detailed signal quality feedback from all subscribers, then link adaptation accuracy is improved, but uplink bandwidth consumption increases
Solution Approach 1:
The patent extracts only the essential information needed for link adaptation by having receivers report solely their signal quality status (above or below threshold) rather than transmitting complete signal quality datasets. This selective extraction maintains sufficient accuracy for determining appropriate MCS parameters while significantly reducing uplink bandwidth requirements.
Solution Approach 2:
The system implements feedback mechanisms where receivers provide concise signal quality indicators to the base station. This feedback loop enables the base station to accurately assess overall signal conditions and adjust transmission parameters without requiring continuous or detailed data streams from all receivers, thus balancing measurement precision with bandwidth efficiency.
3Area of stationary object
If broadcast systems transmit to all receivers uniformly, then coverage is improved, but transmission fees become expensive relative to content quality and quantity
Solution Approach 1:
The patent applies local quality by enabling different modulation and coding schemes (MCS) for different receiver groups based on their individual signal conditions. Instead of using a single uniform transmission parameter for all receivers, the system determines appropriate MCS parameters tailored to each receiver's signal quality, allowing high data rates for receivers with good signal conditions while maintaining acceptable performance for those at cell edges.
Solution Approach 2:
The system dynamically changes transmission parameters such as modulation order and coding rate based on real-time signal quality measurements. By adjusting these parameters according to actual receiver conditions rather than using fixed uniform settings, the system optimizes the balance between coverage and transmission cost efficiency.
Data Source
AI summary
A method and apparatus of link adaptation of a broadcast system is disclosed. The method includes a base station adaptively determining a signal quality threshold. The base station broadcasts a signal, wherein the signal includes the signal quality threshold. A plurality of subscribers receives the signal, and measure a signal quality. Each of a subset of the plurality of subscribers transmits back to the base station an indicator of whether the received signal has a measured signal quality that is either above or below the signal quality threshold. A percentage of subscribers that receive the signal having a received signal quality above the signal quality threshold is estimated. A transmission modulation format and coding is selected based on the estimated percentage.