Discontinuous Transmission for LTE Wi-Fi Coexistence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The coexistence of small cell LTE operations in unlicensed frequency bands with other Radio Access Technologies (RATs) like Wi-Fi leads to interference, as both systems share the same spectrum, resulting in reduced spectral efficiency and capacity.
Innovation Solution
Implementing a Discontinuous Transmission (DTX) communication scheme that alternates between active and inactive periods, allowing LTE to dynamically adjust its transmission patterns based on the utilization of the communication medium, thereby minimizing interference with other RATs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LTE operates continuously in unlicensed bands to maximize spectral efficiency and capacity, then LTE throughput is improved, but interference with other RATs like Wi-Fi increases
Solution Approach 1:
The patent implements Discontinuous Transmission (DTX) where LTE transmissions occur in periodic active periods followed by inactive periods. This periodic operation allows LTE to access the unlicensed spectrum when needed while creating regular opportunities for other RATs like Wi-Fi to operate without interference, thus resolving the contradiction between maximizing LTE spectral efficiency and reducing interference to other systems.
Solution Approach 2:
The patent introduces dynamic adjustment of transmission parameters including variable active period durations, configurable duty cycles, and adaptive power levels. The system can dynamically switch between different transmission states (full power, reduced power, silent) based on traffic conditions and interference levels, allowing flexible optimization of both LTE performance and coexistence with other RATs.
2Object-generated harmful factors
If LTE uses discontinuous transmission to reduce interference with other RATs, then interference is reduced, but LTE capacity and throughput decrease
Solution Approach 1:
The system dynamically adjusts the duty cycle and active period configuration based on traffic demand and interference conditions. When traffic load is high, the active periods can be extended or frequency increased to maintain capacity. When interference is problematic, the system can reduce duty cycle. This dynamic adaptability allows the system to optimize the trade-off between interference reduction and capacity maintenance rather than being fixed at one extreme.
Solution Approach 2:
The patent changes multiple transmission parameters simultaneously including time domain parameters (active period duration, periodicity), frequency domain parameters (subcarrier spacing, bandwidth), and power parameters (transmit power level). By coordinating changes across these different parameter dimensions, the system can maintain effective throughput while reducing peak interference levels.
Data Source
AI summary
Techniques for co-existence between wireless Radio Access Technologies (RATs) are disclosed. During an active period of a Discontinuous Transmission (DTX) communication pattern, a first signal may be transmitted during a first subframe and a second signal may be transmitted during a second subframe, while during an inactive period the first signal may be transmitted during the first subframe and the second signal may be omitted during the second subframe. Retransmission of one or more packets may take place over a subset of less than all retransmission opportunities based on the DTX communication pattern. A Secondary Cell (SCell) may be reconfigured as the Primary Cell (PCell) and the PCell may be reconfigured as the SCell for one or more access terminals based on a load balancing condition or a channel selection condition.