Multi-User MIMO Receiver Separating Mixed Transmission Schemes
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Solution Overview
Problem
Conventional multiuser MIMO systems require all users to employ the same transmission scheme, either single-carrier or multi-carrier, limiting flexibility and throughput, as they cannot separate signals from transmitters using different schemes at the same time and frequency.
Innovation Solution
A multiuser MIMO system that allows multiple transmitters to operate using different transmission schemes, with a receiver capable of separating and processing signals from each transmitter, employing MMSE weights for demultiplexing and flexible frequency scheduling to improve throughput and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If all users employ the same transmission scheme in multiuser MIMO, then signal separation is simplified, but system flexibility and throughput are limited
Solution Approach 1:
The receiver is designed with a universal signal separation mechanism that can handle multiple transmission schemes (single-carrier and multi-carrier) simultaneously. The receiver processes signals from users employing different transmission schemes through a unified framework, enabling flexible system operation without requiring separate processing paths for each scheme.
Solution Approach 2:
The receiver divides the signal processing into distinct modules: a first signal processing unit for single-carrier signals and a second signal processing unit for multi-carrier signals. This segmentation allows independent optimization of processing for each transmission scheme while maintaining overall system coherence and enabling flexible user assignment.
2Productivity
If multi-carrier transmission is used, then throughput is improved, but PAPR becomes problematic for mobile terminals
Solution Approach 1:
The system dynamically assigns transmission schemes to users based on their characteristics and channel conditions. Mobile terminals with power amplifier nonlinearity issues can be assigned single-carrier transmission to ensure reliable operation, while users with cleaner power characteristics can utilize multi-carrier transmission for higher throughput, optimizing the system overall.
Solution Approach 2:
Different transmission schemes are applied to different users based on their specific requirements and channel conditions. The system allows single-carrier transmission for users where PAPR control is critical and multi-carrier transmission for users where throughput is prioritized, creating a heterogeneous but optimized system.
3Reliability
If single-carrier transmission is used, then PAPR is suppressed, but inter-symbol interference cannot be completely suppressed and throughput is lowered
Solution Approach 1:
The system merges single-carrier and multi-carrier transmission modes within the same time-frequency resource block. Multiple users can simultaneously occupy the same resources using different transmission schemes, and the receiver separates their signals through coordinated processing, effectively combining the advantages of both schemes.
Solution Approach 2:
The system applies multi-carrier transmission partially to users who can benefit from the throughput enhancement and have acceptable PAPR characteristics, while using single-carrier transmission for users where PAPR control is more critical. This partial application of multi-carrier mode optimizes the overall system performance.
Data Source
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AI summary
Even when respective transmitters use different transmission schemes, signals of the respective transmitters are separated. A receiver that is applied to a multiuser MIMO system in which a plurality of transmitters performs transmission to at least one receiver, includes a MIMO separation part 40 that receives signals transmitted in different transmission schemes at the same time and at the same frequency and separates the received signals for each transmitter, a switching part 41 that switches output destinations according to the transmission scheme of the separated signal, and a single-carrier processing part 42 and a multi-carrier processing part 43 provided for each transmission scheme for processing a signal output from the switching part 41 according to its transmission scheme.