Antenna Selection Using Frequency-Hopped Sounding Reference Signals
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Solution Overview
Problem
Current antenna selection methods in wireless communication networks, particularly in LTE systems, face challenges in efficiently estimating channels using frequency-hopped sounding reference signals, especially when transceivers are moving rapidly, leading to outdated channel estimates and limited performance improvement.
Innovation Solution
The method involves transmitting frequency-hopped sounding reference signals alternately from subsets of antennas, with a predetermined pattern that adjusts based on the number of subbands and subsets, ensuring that channel estimates are updated periodically and covering the entire bandwidth effectively, thereby improving antenna selection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If frequency-hopped sounding reference signals are used for antenna selection, then channel estimation can be performed across the entire bandwidth, but the channel estimates become outdated when transceivers are moving rapidly
Solution Approach 1:
The patent applies periodic action by transmitting frequency-hopped sounding reference signals in periodic intervals rather than continuously. The sounding reference signals are transmitted periodically across different frequency subbands, allowing the system to balance between bandwidth coverage and maintaining current channel estimate validity. This periodic transmission reduces the time delay between channel estimation updates while still covering the entire bandwidth over multiple periods.
2Measurement precision
If channel estimates are updated frequently to track rapid movements, then estimation accuracy improves, but the signaling overhead and processing complexity increase
Solution Approach 1:
The patent segments the bandwidth into multiple subbands and assigns different antenna subsets to different subbands for transmitting frequency-hopped sounding reference signals. This segmentation allows parallel channel estimation across multiple subbands, reducing the overall processing complexity while maintaining accurate channel estimates. Each antenna subset handles a specific subband, distributing the processing load and enabling efficient tracking of rapid channel changes.
Solution Approach 2:
The patent uses partial action by transmitting sounding reference signals from only a subset of antennas at any given time rather than all antennas simultaneously. Different antenna subsets are activated in different time intervals or frequency subbands, reducing the processing complexity and signaling overhead while still achieving comprehensive channel estimation through the frequency-hopping pattern.
3Device complexity
If antenna selection is performed to reduce hardware complexity, then the number of RF chains is reduced, but the system performance degrades compared to full MIMO
Solution Approach 1:
The patent applies dynamics by implementing adaptive antenna selection where the subset of antennas is not fixed but dynamically selected based on current channel conditions. The system periodically updates the antenna subset configuration using frequency-hopped sounding reference signals to track channel variations, allowing the antenna selection to adapt to changing environmental conditions and maintain system capacity close to full MIMO performance.
Solution Approach 2:
The patent changes parameters by varying the antenna subset configuration and frequency hopping patterns based on channel quality indicators. The system adjusts which antennas are active and how frequency resources are allocated across different antenna subsets, optimizing the balance between hardware complexity reduction and maintaining system capacity through parameter adaptation rather than fixed configuration.
Data Source
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AI summary
Embodiments of the invention describe a method for antenna selection (AS) in a wireless communication network. The network includes a base station and a transceiver, wherein the transceiver has a set of antennas, and wherein the transceiver is configured to transmit a frequency-hopped sounding reference signal (SRS) from a subset of antennas at a time. The base station determines a type of a training transmission based on a number of the subbands and a number of subsets in the set of antennas, and transmits an instruction including the type to the transceiver.