Dynamic Modulation and Coding for Wireless Signal Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face challenges in maximizing channel capacity for cell-edge users due to low Signal-to-Noise Ratio (SNR) and severe interference from neighboring cells, limiting overall system performance.
Innovation Solution
A method and apparatus that select between Quadrature Amplitude Modulation (QAM) and advanced QAM schemes based on received signal strength, Hybrid Automatic Repeat Request (HARQ) support, and non-Gaussian neighbor cell interference, using different channel coding schemes to optimize modulation efficiency and adapt transmission parameters for improved spectral efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If advanced QAM schemes are used for cell-edge users, then spectral efficiency is improved, but system reliability deteriorates due to low SNR and severe interference
Solution Approach 1:
The patent implements dynamic modulation and coding scheme selection that adapts to channel conditions. The system transitions between QAM and advanced QAM schemes based on real-time SNR measurements and interference levels, allowing optimal performance across varying channel quality while maintaining reliability through fallback to more robust schemes when conditions deteriorate
Solution Approach 2:
The system changes key transmission parameters including modulation order, coding rate, and resource allocation based on channel conditions. By adjusting these parameters dynamically, the system achieves high spectral efficiency when conditions permit while ensuring transmission reliability through more conservative parameter settings when SNR is low or interference is severe
2Productivity
If higher data rates are pursued through advanced modulation schemes, then channel capacity increases, but transmission performance deteriorates under low SNR conditions
Solution Approach 1:
The system dynamically adjusts the modulation scheme and coding rate based on measured SNR and channel quality indicators. This allows the data rate to be maximized when channel conditions are good while automatically reducing to more robust, lower-rate transmissions when SNR deteriorates, thus maintaining transmission performance across varying conditions
Solution Approach 2:
The system employs feedback mechanisms where the receiver measures channel quality and SNR, then reports back to the transmitter. This feedback enables the transmitter to select appropriate modulation and coding schemes that achieve high data rates when possible while ensuring reliable transmission when channel conditions are poor
Data Source
Figure 1A(a)~1B(c)
Figure 1C(a)~1C(c)
Figure 1D~1E
AI summary
Disclosed is a method and device for transmitting and receiving a signal by using modulation techniques in a wireless communication system. The method according to the present invention includes: selecting one of QAM and improved QAM according to at least one predefined criterion; encoding information bits to be transmitted according to a first encoding scheme and mapping encoded information bits to QAM symbols when the QAM is selected; encoding information bits to be transmitted according to a second encoding scheme and mapping encoded information bits to improved QAM symbols when the improved QAM is selected; and transmitting the QAM symbols or the improved QAM symbols through a given resource region.