Wireless Receiver Pilot Phase Rotation for Multi-User Diversity
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Solution Overview
Problem
Conventional communication systems fail to achieve an adequate multi-user diversity effect due to limitations in allocated slot and receiver location in wireless communication systems.
Innovation Solution
A wireless receiver is designed with multiple transmission antennas, where phase rotation is applied to pilot channels to control the maximum delay time between antennas, allowing for improved channel estimation and demodulation, and the rotation amount is set based on the frequency bandwidth to optimize multi-user diversity effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blocks which are wide in the frequency direction are allocated to obtain frequency diversity effect, then error rate is reduced with low receiving power, but multi-user diversity effect cannot be obtained
Solution Approach 1:
The frequency band is segmented into multiple subcarriers, and different allocation strategies are applied to different users based on their channel conditions. Some users receive wide frequency blocks for frequency diversity, while others receive narrow blocks for multi-user diversity, allowing both effects to coexist in the same system.
Solution Approach 2:
The patent implements dynamic resource allocation where the allocation strategy (wide vs. narrow blocks) is adaptively determined based on real-time channel conditions, user location, and system load. This dynamic approach allows the system to optimize between frequency diversity and multi-user diversity effects for different users and time slots.
2Productivity
If blocks which are narrow in the frequency direction are allocated to obtain multi-user diversity effect, then user-specific optimization is achieved, but frequency diversity effect is reduced
Solution Approach 1:
Different quality characteristics are applied to different frequency resources allocated to different users. Users experiencing fading in certain frequency regions are allocated narrow blocks in those regions, while other users may receive wide blocks in different frequency regions, allowing each user to receive optimized local resource allocation.
3Measurement precision
If phase rotation is applied to control maximum delay time between transmission antennas, then channel estimation accuracy is improved, but system complexity increases
Solution Approach 1:
Phase rotation is applied in advance to the transmitted pilot signals before they are sent over the channel. This preliminary action ensures that the received pilot signals have known phase relationships, making channel estimation simpler and more accurate without requiring complex post-processing at the receiver.
Data Source
AI summary
A wireless receiver receiving a signal from a wireless transmitter which includes a plurality of transmission antennas and transmits data to which first phase rotation for controlling the maximum delay time between the plurality of transmission antennas is added and pilot channels corresponding to the plurality of transmission antennas which are orthogonal to each other, where the wireless receiver includes a reception unit which receives the pilot channels and a demodulating unit which demodulates the data.