Phase Shift Precoding Matrix for Open Loop MIMO Reliability
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Solution Overview
Problem
Conventional phase shift diversity and precoding schemes face limitations in achieving high data transmission rates and are not suitable for environments with excessive channel variation, particularly in open loop systems.
Innovation Solution
A phase shift based precoding method using a generalized phase shift based precoding matrix that applies different phase sequences to all streams transmitted via multiple antennas, with a precoding matrix designed to satisfy power and orthogonality constraints, allowing for flexible channel state management and feedback information integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional phase shift diversity or precoding schemes are used, then frequency diversity gain can be obtained, but data transmission rate is limited and reliability deteriorates in open loop systems with channel variation
Solution Approach 1:
The patent merges phase shift diversity and precoding into a unified phase shift based precoding scheme that combines the frequency diversity characteristics of phase shift diversity with the SNR optimization of precoding. The generalized precoding matrix incorporates phase shift sequences that provide both diversity and beamforming effects simultaneously, achieving high data transmission rates while maintaining reliability even in open loop systems.
Solution Approach 2:
The patent changes the parameter of phase shift sequences by applying different phase shift patterns to different antennas and subcarriers. The generalized precoding matrix uses configurable phase shift parameters that can be optimized for different channel conditions, enabling the system to adapt to varying channel states and achieve both high rate and high reliability transmission.
2Reliability
If conventional precoding schemes are used, then SNR can be maximized in closed loop systems, but they are not suitable for open loop systems with excessive channel variation
Solution Approach 1:
The generalized phase shift based precoding matrix serves multiple functions: it provides frequency diversity like phase shift diversity, optimizes SNR like precoding, and maintains performance in both open loop and closed loop systems. This universal scheme adapts to different channel conditions through configurable phase shift parameters, making it suitable for various deployment scenarios including open loop systems with channel variation.
Solution Approach 2:
The patent introduces dynamic phase shift parameters that can be adjusted based on channel conditions. The generalized precoding matrix allows for time-varying phase shifts that adapt to channel variations, enabling the system to maintain reliability in open loop conditions while preserving the ability to optimize for closed loop scenarios when feedback is available.
3Reliability
If phase shift diversity is applied to all streams, then frequency diversity gain is achieved, but spatial multiplexing rate is limited to 1
Solution Approach 1:
The patent applies local quality by differentiating the phase shift application across different streams and antennas. The generalized precoding matrix applies phase shifts selectively to different spatial layers and frequency subcarriers, allowing some streams to benefit from diversity while others maintain higher multiplexing rates. This localized application of phase shifting enables both diversity gain and spatial multiplexing to coexist.
Data Source
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AI summary
A method of transmitting data using a generalized phase shift based precoding or an extended phase shift precoding scheme in a multiple-antenna system using a plurality of subcarrier and a transceiver for supporting the same are disclosed. A phase shift based precoding matrix may be generalized and determined by a product of a diagonal matrix for phase shift and a unitary matrix for maintaining orthogonality in spatial domain. The diagonal matrix may be extended by a product of a precoding matrix for increasing channel power and the diagonal matrix for phase shift. The design of the transceiver can be simplified or communication efficiency can be improved by generalizing and extending the phase shift based precoding.