OFDMA Scheduling for RF Leakage Reduction
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Solution Overview
Problem
Existing wireless communication systems face interference issues due to radio frequency (RF) transmitter leakage, which is costly to mitigate using external SAW filters, and becomes more challenging with multiple-band transceivers and high power transmission.
Innovation Solution
A scheduling method that determines and optimizes the transmit power of mobile terminals to allocate uplink and downlink frequency carriers with maximum duplex distance, minimizing power leakage from the transmitter to the receiver, and avoids overlap with interfering frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If external SAW filters are used to minimize transmitter leakage to receiver, then receiver noise is reduced, but device cost and complexity increase
Solution Approach 1:
The scheduler performs preliminary action by determining transmit power levels before resource allocation, and uses this information to pre-calculate optimal duplex distances that minimize leakage without requiring external filters
Solution Approach 2:
The invention changes the parameter of duplex distance dynamically based on transmit power levels. By adjusting the frequency separation between uplink and downlink carriers according to power conditions, the system minimizes leakage effects without adding physical filtering components
2Reliability
If transmit power is increased to improve uplink coverage, then transmission reliability improves, but transmitter leakage to receiver increases
Solution Approach 1:
The system dynamically changes the duplex distance parameter based on transmit power levels. When high transmit power is required for coverage, the scheduler increases the frequency separation between uplink and downlink carriers, thereby maintaining reliability while reducing leakage to acceptable levels
3Object-affected harmful factors
If duplex distance is increased to reduce leakage, then receiver noise decreases, but frequency resource availability decreases
Solution Approach 1:
The system makes the duplex distance dynamic rather than fixed. The scheduler adjusts the frequency separation adaptively based on current transmit power requirements, allowing small duplex distances when power is low (maximizing resource availability) and larger distances when power is high (minimizing leakage)
Solution Approach 2:
By changing the duplex distance parameter dynamically according to transmit power conditions, the system optimizes both receiver noise performance and frequency resource utilization without compromise
Data Source
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AI summary
The present invention relates to scheduling of uplink and downlink resources between mobile terminals (110) and a base station (130). To reduce the power leakage between the transmitter and the receiver of the mobile terminal (110), the scheduler allocated uplink frequency carriers and downlink frequency carriers with a larger duplex distance to those mobile terminals (110,120) that has to transmit with high power. This means that the requirements on the external SAW filter could be reduced.