Relay Station Space Division Duplex for Cellular Networks
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Solution Overview
Problem
In cellular networks based on relay stations, the existing duplex methods are inefficient in utilizing channel resources, leading to reduced network performance due to the need for multiple slots for uplink and downlink signals, which limits the coverage area and throughput, especially in high-frequency bands prone to path loss and fading.
Innovation Solution
A space division duplex communication method where the relay station receives and combines uplink and downlink signals in the same slot, allowing orthogonal transmission and reception, thereby improving channel use efficiency and simplifying resource allocation without requiring special processing for different user types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If time division duplex is used in relay station, then covering area is expanded, but channel use efficiency deteriorates due to requiring multiple slots for uplink and downlink
Solution Approach 1:
The patent transitions from time-domain separation (TDD) to spatial-domain separation (SDM) for duplexing. By utilizing multiple antennas at the relay station, uplink and downlink signals are transmitted simultaneously in different spatial dimensions, eliminating the need for time slot separation and thereby improving channel use efficiency while maintaining expanded coverage area.
Solution Approach 2:
The system dynamically switches from traditional TDD resource allocation to SDT-based spatial multiplexing. The relay station adaptively manages multiple antenna resources to simultaneously handle uplink and downlink transmissions, dynamically optimizing resource utilization and eliminating the fixed time-slot constraints of TDD.
2Reliability
If relay station uses orthogonal frequency and code channels for transmission and reception, then interference is reduced, but resource allocation complexity increases
Solution Approach 1:
The patent changes the fundamental parameter for signal separation from orthogonal frequency/code channels to spatial channels. By utilizing the spatial dimension created by multiple antennas, the system maintains interference reduction while simplifying resource allocation, as spatial multiplexing naturally separates uplink and downlink signals without requiring complex orthogonal resource management.
3Reliability
If relay station transmits and receives in different time slots, then near-far effect is avoided, but throughput is reduced by half compared to traditional network
Solution Approach 1:
The patent moves the separation dimension from time to space. By using multiple antennas to create spatially separated transmission and reception paths, the system avoids the near-far effect while enabling simultaneous uplink and downlink transmissions, thereby maintaining high throughput without the 50% reduction inherent in TDD approaches.
Data Source
AI summary
A cellular network that is based on relay station and a space division duplex communication method are disclosed. The cellular network based on RS includes a base station, a RS and a UE, wherein the base station has at least one antenna and the RS has at least two antennas. The base station allocates resources for the UE, transmits a downlink signal in a current slot and receives an uplink signal from the UE through the RS in a next slot; the RS receives the downlink signal from the base station and the uplink signal from the UE in the current slot and transmits the received downlink signal to the UE and the uplink signal to the base station in the next slot; the UE transmits the uplink signal in the current slot and receives the downlink signal through the RS in the next slot, wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal. With the cellular network and the communication method of embodiments of the present invention, the use efficiency of each channel can be improved effectively and the system complexity can be reduced.