MIMO Symbol Transmission via Hybrid HARQ and Space-Time Coding
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Solution Overview
Problem
MIMO networks face challenges in increasing reliability and eliminating self-interference due to the use of multiple antennas, which affects the decoding of symbols and increases noise power, especially in systems with a larger number of antennas.
Innovation Solution
The integration of hybrid automatic repeat requests (HARQ) with space-time coding (STC) and the use of specific coding schemes such as Alamouti codes and self-interference cancellation codes (SICC) during retransmissions to eliminate self-interference and improve decoding reliability in MIMO networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple antennas are used for spatial multiplexing, then transmission capacity is improved, but self-interference increases
Solution Approach 1:
The patent applies space-time coding to convert the harmful self-interference generated by multiple antennas into a beneficial diversity effect. By encoding symbols across multiple antennas and time slots, the system transforms the interference problem into an opportunity for improved reliability through coherent combining at the receiver, thereby maintaining high transmission capacity while mitigating self-interference.
Solution Approach 2:
The patent employs composite space-time codes that combine multiple coding schemes (including Alamouti codes and self-interference cancellation codes) to create a unified transmission framework. This composite approach integrates the advantages of different coding methods to simultaneously achieve high data rates and effective self-interference elimination across multiple antennas.
2Productivity
If multiple antennas are used for spatial multiplexing, then transmission capacity is improved, but reliability of symbol decoding deteriorates
Solution Approach 1:
The patent transforms the reliability-deteriorating effect of self-interference into a reliability-improving mechanism by using space-time coding. The coding scheme ensures that signals from multiple antennas are combined coherently at the receiver, converting what would be destructive interference into constructive combining that enhances signal strength and decoding reliability while maintaining high transmission capacity.
Solution Approach 2:
The patent changes the transmission parameters by applying space-time encoding across multiple antennas and time slots. This parameter transformation allows the system to maintain high data rates while improving decoding reliability through diversified transmission paths and coherent combining, effectively decoupling the trade-off between capacity and reliability.
3Reliability
If space-time coding is applied to eliminate self-interference, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent segments the complex space-time coding problem into manageable components by using structured code designs such as Alamouti codes for 2x2 MIMO and orthogonal designs for larger configurations. This segmentation allows the receiver to process signals through systematic steps (correlation, combining, decoding) rather than facing a monolithic complex problem, thereby reducing implementation complexity while maintaining high reliability and self-interference elimination performance.
Data Source
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AI summary
A method transmits a block of symbols in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas. A block of symbols is coded with a first code to generate a first block, which is transmitted and received. If a decoding of the first block is incorrect, then block of symbols is coded with the first code and then a second code different than the first code to generate a second block. The second block is transmitted, received and combined with the first block to recover the block of symbols.