Space-Time Encoding for OFDM MIMO Data Transmission
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Solution Overview
Problem
Current wireless communication systems in the millimeter-wave band face challenges in achieving high-speed data transmission and efficient channel utilization, particularly in supporting multiple-input multiple-output (MIMO) communications, due to limitations in existing IEEE 802.11 standards and the inability to simultaneously transmit to multiple stations using MU-MIMO schemes.
Innovation Solution
The implementation of a space-time encoding scheme for OFDM MIMO transmissions, which involves mapping data symbols and pilot sequences across multiple spatial streams, using a pilot mapping scheme that includes sign inversion and complex conjugation, to enable efficient channel bonding and diversity gain, thereby supporting high-data-rate transmissions over directional frequency bands like 60 GHz.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If space-time encoding scheme is implemented for OFDM MIMO transmissions, then data transmission rate is improved (up to 30 Gbps), but device complexity increases due to mapping data symbols and pilot sequences across multiple spatial streams
Solution Approach 1:
The patent segments the transmission by dividing data symbols and pilot sequences into multiple spatial streams, where each stream is independently encoded and transmitted through separate antennas. This segmentation enables parallel transmission paths that collectively achieve high data rates while maintaining manageable complexity through modular processing of each stream.
Solution Approach 2:
The patent introduces spatial dimensionality by mapping data symbols and pilot sequences across multiple spatial streams and antennas. This dimensional expansion from single-antenna to multi-antenna transmission enables MIMO capabilities, achieving higher throughput by utilizing the spatial domain as an additional transmission dimension.
2Adaptability or versatility
If channel bonding is supported through space-time encoding, then channel utilization is improved, but receiver processing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-mapping pilot sequences and data symbols to specific spatial streams and subcarriers according to defined patterns before transmission. This preliminary organization of signals enables the receiver to efficiently process bonded channels through structured, predictable patterns rather than requiring complex adaptive processing.
3Productivity
If MU-MIMO transmissions are enabled, then network capacity is improved, but ability to simultaneously transmit to multiple stations is limited by existing standards
Solution Approach 1:
The patent implements multi-functionality by designing a space-time encoding scheme that can simultaneously support multiple spatial streams for different stations. The same encoding framework and resource mapping structure serve both single-user and multi-user scenarios, enabling the system to adaptively serve multiple stations concurrently without requiring separate transmission mechanisms.
Data Source
AI summary
For example, a wireless station may be configured to map a plurality of data symbols to Orthogonal Frequency-Division Multiplexing (OFDM) symbols in a plurality of spatial (space-time) streams, to map a plurality of modulated pilot sequences to the OFDM symbols according to a pilot mapping scheme, and to transmit an OFDM Multiple-Input-Multiple-Output (MIMO) transmission based on the plurality of spatial streams.