Base Station Antenna Directivity Control Using Known Signals
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Solution Overview
Problem
Base stations in communication systems, such as LTE, face challenges in enhancing transmission performance using adaptive array antenna systems, particularly in controlling transmission directivity effectively for improved communication.
Innovation Solution
The implementation of a communication method that controls the transmission directivity of multiple antennas in a base station based on known signals transmitted from communication terminals, using a combination of first and second known signals to perform beamforming and null steering, and allocating radio resources to manage uplink and downlink communications efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station uses adaptive array antenna system to control transmission directivity, then transmission performance is improved, but the system complexity increases due to multiple antennas and directivity control mechanisms
Solution Approach 1:
The base station performs preliminary directivity control using the first known signal received on the associated uplink radio resource before actual downlink communication. This preliminary action establishes the transmission directivity in advance, allowing the system to maintain high transmission performance while reducing real-time processing complexity during actual data transmission.
Solution Approach 2:
The patent introduces a second known signal as an intermediary mechanism. When the first known signal is not transmitted on the associated uplink resource, the second known signal received on a non-associated uplink radio resource serves as a substitute intermediary to determine transmission directivity. This intermediary approach maintains system reliability while providing flexibility in resource allocation.
2Measurement precision
If the base station allocates specific uplink radio resources for first known signal transmission to enable precise beamforming and null steering, then transmission directivity control is improved, but radio resource management complexity increases
Solution Approach 1:
The patent makes the uplink radio resources universal by allowing them to serve multiple purposes: associated uplink resources for precise beamforming with the first known signal, and non-associated uplink resources for receiving the second known signal as a substitute. This multi-functionality enables the system to maintain precise directivity control while reducing radio resource management complexity through flexible resource allocation.
Solution Approach 2:
The system dynamically changes the parameter of which known signal to use for directivity control. When the first known signal is available on the associated uplink resource, it is used for precise beamforming. When unavailable, the system switches to using the second known signal from the non-associated uplink resource. This parameter change approach maintains measurement precision while simplifying resource management through adaptive selection.
3Measurement precision
If the base station waits for the first known signal on the associated uplink radio resource for optimal beamforming, then directivity accuracy is improved, but communication delay increases when the signal is not transmitted
Solution Approach 1:
The base station performs preliminary directivity control using available known signals before actual downlink communication begins. By using the second known signal from the non-associated uplink resource as a substitute when the first known signal is unavailable, the system establishes transmission directivity in advance, avoiding delays during actual data transmission while maintaining acceptable beamforming accuracy.
Solution Approach 2:
Instead of strictly waiting for the first known signal on the associated uplink resource, the patent inverts the approach by accepting the second known signal from the non-associated uplink resource as a valid alternative. This inversion eliminates the waiting delay while maintaining the capability for effective directivity control, thus reducing communication delay without completely sacrificing beamforming accuracy.
Data Source
AI summary
For downlink communication with a communication terminal using a downlink radio resource allocated to this communication terminal by a radio resource allocating unit, if this communication terminal does not transmit a first known signal using an associated uplink radio resource associated with this downlink radio resource but it transmits the first known signal using a nonassociated uplink radio resource which is not associated with this downlink radio resource and which includes the frequency band of this downlink radio resource in a frequency direction, a communication unit controls the transmission directivity of a plurality of antennas based on a second known signal if the aforementioned communication terminal transmits the second known signal in the frequency band of the aforementioned downlink radio resource in an interval between a time period of this downlink radio resource and a time period of the aforementioned nonassociated uplink radio resource.