Massive MIMO Pilot Signal Allocation via Angle Domain Transformation
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Solution Overview
Problem
In massive MIMO antenna systems, the overhead of channel estimation increases with the number of antennas, limiting data throughput due to the need for multiple physical resource units to send orthogonal pilot signals, which is not effectively addressed in current technologies.
Innovation Solution
An electronic device determines channel characteristics in the angle domain and transforms them into orthogonal pilot signals for transmission over multiple antennas, reducing the overhead of channel estimation by selecting only significant angles and pilot signals, thereby optimizing pilot signal allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional orthogonal pilot signals are sent via different antennas to achieve channel estimation, then channel state information can be obtained, but the number of physical resource units required increases with the number of antennas, increasing overhead and limiting data throughput
Solution Approach 1:
The patent transforms the channel estimation problem from the spatial domain (transmitting orthogonal pilot signals via different antennas) to the angle domain (identifying significant propagation angles). By changing the dimension of analysis from antenna indices to angle of arrival/departure, the system can characterize channels using a smaller set of angular parameters that capture the essential channel characteristics without requiring pilot signals for every antenna.
Solution Approach 2:
The patent extracts only the significant propagation angles from the channel characteristics in the angle domain, rather than processing all antenna channels equally. By identifying and focusing on the dominant angular components that contribute most to the channel response, the system can achieve accurate channel estimation while requiring pilot signals only for these significant angles, thereby reducing the overall pilot overhead.
2Productivity
If the number of antennas increases to improve diversity gain and multiplexing gain, then spectrum efficiency and energy efficiency improve, but the overhead of channel estimation increases, greatly limiting data throughput rate
Solution Approach 1:
The patent introduces the angle domain as an alternative representation of the channel, where the channel characteristics are transformed from antenna-space to angle-space. This dimensional transformation allows the system to exploit the geometric structure of wireless propagation, where signals typically arrive from limited angular directions even when many antennas are present. By working in the angle domain, the system can achieve accurate channel estimation with fewer pilot resources regardless of the number of antennas.
Solution Approach 2:
The patent changes the parameter representation from antenna indices to angular parameters (angle of arrival and angle of departure). Instead of characterizing the channel by which antenna receives/transmits signals, the system characterizes it by the propagation angles. This parameter change allows the system to capture channel essentiaL characteristics using a compact angular representation that scales better with the number of antennas, thereby reducing pilot overhead while maintaining spectral efficiency.
3Reliability
If orthogonal pilot signals are transmitted through multiple antennas to achieve channel estimation, then channel state information is obtained, but the data throughput rate is greatly limited due to increased overhead
Solution Approach 1:
The patent extracts the essential channel information by identifying significant propagation angles in the angle domain, rather than requiring complete pilot signals for all antennas. By focusing computational and transmission resources only on the dominant angular components that carry the most channel information, the system achieves reliable channel state estimation while minimizing the pilot overhead that would otherwise consume valuable data transmission resources.
Solution Approach 2:
The patent applies partial action by transmitting pilot signals only for the significant angles identified in the angle domain, rather than transmitting pilots for all possible antenna combinations. This partial pilot transmission strategy provides sufficient channel state information for reliable communication while leaving more resources available for actual data throughput, effectively balancing reliability and productivity.
Data Source
AI summary
An electronic device, and method, at a first communication apparatus having multiple antennas includes a memory for storing computer instructions; and a processing circuit configured to execute the stored computer instructions to: based on channel states of channels between the multiple antennas of the first communication apparatus and a second communication apparatus, determine channel characteristics of a first channel from the first communication apparatus to a second communication apparatus in an angle domain; based on the determined channel characteristics of the first channel in the angle domain, determine a first set of pilot signals used in the angle domain, the pilot signals in the first set of pilot signals being orthogonal to each other; and transform the first set of pilot signals into a second set of pilot signals for transmission over the multiple antennas of the first communication apparatus.