Concurrent TDD-FDD Spectrum Sharing for Asymmetric LTE Traffic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LTE FDD networks face inefficiency due to asymmetric mobile data usage, where downlink channels are congested while uplink channels are underutilized, leading to wasteful use of limited spectrum.
Innovation Solution
Implementing Distributed-Input Distributed-Output (DIDO) technology and Multiuser Multiple Antenna Systems (MU-MAS) to enable concurrent spectrum usage by allowing user devices to operate in TDD mode within currently used FDD spectrum, coordinating UL and DL channels to avoid interference and optimize spectrum utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If FDD networks use dedicated uplink and downlink frequency channels, then full-duplex communication is enabled, but spectrum utilization efficiency deteriorates due to asymmetric data usage patterns
Solution Approach 1:
The patent merges TDD and FDD networks by allowing TDD user devices to operate concurrently with FDD networks in the same frequency band. The base station coordinates transmissions between TDD and FDD devices, enabling the downlink channel to serve both TDD and FDD users simultaneously, thereby improving spectrum utilization efficiency by combining the benefits of both duplexing modes.
Solution Approach 2:
The base station is designed with multi-functionality to handle both TDD and FDD communication modes simultaneously. It can dynamically allocate resources and coordinate transmissions for different device types (TDD-capable and FDD-only devices) within the same frequency band, making the system universally compatible with various device capabilities while optimizing spectrum usage.
2Productivity
If TDD mode is implemented to match asymmetric data usage, then spectrum efficiency improves, but compatibility with existing FDD devices deteriorates
Solution Approach 1:
The patent segments the user device population into two groups: TDD-capable devices that can operate in TDD mode for efficient asymmetric data transmission, and FDD-only devices that continue to use traditional FDD mode. The base station manages these segments separately, applying appropriate transmission coordination for each group, thereby maintaining compatibility with existing devices while enabling advanced functionality for capable devices.
Solution Approach 2:
The system dynamically adapts its operation mode based on device capabilities. The base station identifies whether each device is TDD-capable or FDD-only and dynamically adjusts its transmission coordination strategy accordingly. This dynamic approach allows the network to optimize performance for TDD devices while maintaining seamless compatibility with legacy FDD devices.
3Productivity
If downlink channel capacity is increased to handle congested traffic, then data throughput improves, but uplink channel underutilization worsens
Solution Approach 1:
The patent enables continuous useful action in the uplink direction by allowing TDD devices to transmit uplink data during periods when FDD downlink is active. The base station coordinates TDD uplink transmissions to occur in time slots that do not conflict with FDD downlink, thereby continuously utilizing the uplink spectrum resource that would otherwise remain idle during FDD downlink periods.
Data Source
AI summary
Systems and methods are described to concurrently utilize actively used spectrum for new TDD or FDD networks, and also for enabling Distributed-Input Distributed Output (DIDO) techniques to be used with both the new networks and the existing networks in the same spectrum.