Communication Device Phase Rotation Channel Estimation
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Solution Overview
Problem
In radio communication systems, accurately estimating channel responses from multiple antennas is challenging due to signal interference, especially when multiple antennas transmit different multicarrier signals or when a terminal near a cell edge receives signals from adjacent cells using the same frequency band, leading to decreased accuracy in identifying transmitting antennas or base stations.
Innovation Solution
By applying different phase rotations to symbols transmitted from multiple antennas, the receiving side can separate and calculate delay profiles, allowing for precise identification of transmitting antennas or base stations, and using different preamble patterns or time shifts to enhance separation accuracy, especially in scenarios with many delay profiles to separate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple antennas transmit different multicarrier signals simultaneously, then data transmission capacity increases, but signal interference increases and channel response estimation accuracy deteriorates
Solution Approach 1:
The patent segments the channel estimation process by separating delay profiles from different antennas through time-shifting. Each antenna's delay profile is calculated at a different time position, allowing the receiver to distinguish and estimate channel responses from multiple antennas independently without mutual interference
Solution Approach 2:
The patent introduces a time dimension to differentiate signals from multiple antennas. By time-shifting delay profiles in the time domain, the system adds a temporal dimension to antenna identification, enabling clear separation of overlapping multicarrier signals that would otherwise interfere with each other
2Adaptability or versatility
If terminals near cell boundaries receive signals from adjacent cells using the same frequency band, then frequency utilization efficiency improves, but signal identification accuracy deteriorates
Solution Approach 1:
The patent segments interference from adjacent cells by applying cell-specific time shifts to delay profiles. Each cell's signals are separated in the time domain through this segmentation approach, allowing terminals to identify and process signals from different cells independently even when they occupy the same frequency band
Solution Approach 2:
The patent uses time-shifting as an intermediary mechanism to resolve signal confusion from adjacent cells. By introducing distinct time positions for different cells' delay profiles, the system creates a temporal mediator that enables clear signal identification without requiring frequency separation
Data Source
AI summary
Improving the accuracy of estimation of channel responses in receiving signals from a plurality of antennas is disclosed. A transmitting device of a base station includes a preamble A generating unit 010, a preamble B generating unit 011, phase rotating units 012 and 013, multiplexing units 014 and 015, an forward error correction coding unit 016, an S/P converting unit 017, a mapping unit 018, a changeover switch 019, IDFT (or IFFT) units 020 and 026, P/S converting units 021 and 027, GI (Guard Interval) inserting units 022 and 028, D/A converting units 023 and 029, radio transmitting units 024 and 030 and antenna units 025 and 031. In the preamble A generating unit 010 and the preamble B generating unit 011, a preamble A and a preamble B (see the packet format in FIG. 1) are generated, respectively. The preamble A is outputted to the multiplexing units 014 and 015, while the preamble B is outputted to the phase rotating units 012 and 013. The phase rotating units 012 and 013 to which the preamble B has been inputted give continuous phase rotation to subcarriers of the preamble B. In the transmitting device of the base station according to this embodiment, the phase rotating unit 012 does not give phase rotation, but only the phase rotating unit 013 gives phase rotation to the preamble B.