Channel Estimation Using Vector Groups to Remove RF Switches
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Solution Overview
Problem
In multichannel microwave communications systems, the use of radio frequency switches and variable gain amplifiers for channel estimation leads to increased insertion loss, nonlinearity, and limited gain suppression, resulting in degraded link performance and low precision of channel estimation results, along with increased system cost and volume.
Innovation Solution
A channel estimation method that involves obtaining training vector groups for the transmit and receive ends, performing subchannel estimation procedures multiple times to obtain subchannel estimated coefficients, and determining a real channel matrix using these coefficients without relying on radio frequency switches or variable gain amplifiers, thereby avoiding the need for extra circuit devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radio frequency switches are added on each subchannel for channel estimation, then subchannel parameters can be obtained separately, but insertion loss increases and link performance degrades
Solution Approach 1:
The patent extracts and removes the radio frequency switches from the channel estimation path. Instead of using switches to select subchannels, the system directly estimates channel parameters by processing received signals through mathematical operations (correlation, matrix inversion) without physical switching components, thereby eliminating insertion loss while maintaining estimation precision
Solution Approach 2:
The patent replaces the mechanical/electrical radio frequency switching system with a signal processing-based estimation system. Channel parameters are obtained through computational methods (cross-correlation, least squares estimation) rather than physical switching, substituting a mechanical component with an algorithmic solution that avoids insertion loss
2Ease of operation
If variable gain amplifiers are added on each subchannel for channel estimation, then gain control is achieved, but nonlinearity increases and gain suppression capability is limited
Solution Approach 1:
The patent removes variable gain amplifiers from the channel estimation path. Gain control is achieved through digital signal processing and mathematical normalization rather than analog amplification, eliminating the source of nonlinearity while maintaining the ability to control signal levels through computational means
Solution Approach 2:
The patent replaces the analog variable gain amplifier system with a digital signal processing system. Gain adjustment is performed through software-based operations (normalization, scaling algorithms) rather than analog amplification, substituting a non-linear analog component with a linear digital processing approach
3Measurement precision
If radio frequency switches or variable gain amplifiers are added on each subchannel, then channel parameters can be estimated, but system cost and volume increase
Solution Approach 1:
The patent extracts and removes the bulky radio frequency switches and variable gain amplifiers from the system architecture. Channel estimation is achieved using only the essential antenna elements and digital signal processing resources already present in the system, eliminating unnecessary hardware volume and cost
Solution Approach 2:
The patent makes the existing antenna elements and signal processing units perform multiple functions: they are used both for normal communication and for channel estimation. This multi-functionality eliminates the need for dedicated estimation hardware, reducing system volume and cost while maintaining full channel estimation capability
Data Source
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AI summary
The present invention discloses a channel estimation method, apparatus, and device and a multichannel microwave communications system. According to the channel estimation method, a first vector group corresponding to a transmit end and a second vector group corresponding to a receive end are first obtained according to a transmit-receive array size; then a subchannel estimation procedure is performed multiple times according to the transmit-receive array size, the first vector group, and the second vector group, to obtain multiple corresponding subchannel estimated coefficients; and finally, a real channel matrix is determined according to the first vector group, the second vector group, and an estimation matrix consisting of the multiple subchannel estimated coefficients. According to the method, apparatus, and system, in a corresponding communications system, an accurate channel matrix can be obtained by means of estimation without adding any extra circuit device, thereby avoiding a problem that channel link performance degrades or precision of a channel estimation result is low because a radio frequency switch or a variable gain amplifier is added in the communications system, lowering a system cost, and reducing a system volume.