MU-MIMO Preamble Interference Nullification Matrix
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Solution Overview
Problem
Existing wireless network systems face interference challenges when multiple client devices transmit data simultaneously, leading to reduced data transmission capacity and efficiency.
Innovation Solution
The implementation of a client device and access point system that uses a preamble interference nullification matrix and distributed orthogonal spreading to manage channel state information, allowing simultaneous data transmissions by multiple clients while minimizing interference through phase and cyclic shift delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple client devices transmit data simultaneously using traditional wireless protocols, then the data transmission capacity increases, but interference between transmissions increases causing reduced efficiency
Solution Approach 1:
The patent segments the transmission process into distinct phases: a preamble phase where multiple clients transmit simultaneously with orthogonal signatures, followed by a data phase where interference is managed using channel state information obtained from the preamble. This segmentation allows simultaneous transmissions while controlling interference through structured signal design.
Solution Approach 2:
The patent introduces an intermediary preamble transmission phase that mediates between multiple simultaneous clients and the access point. The preamble acts as an intermediary signal that carries channel state information without carrying actual data, allowing the system to prepare for and manage subsequent data transmissions from multiple clients simultaneously.
2Object-generated harmful factors
If traditional channel contention protocols are used to manage simultaneous transmissions, then interference is reduced through sequential access, but data transmission capacity and network efficiency decrease
Solution Approach 1:
The patent implements periodic action by introducing cyclic shifts to the preamble sequences transmitted by different clients. These cyclic shifts create time-domain separation patterns that allow the access point to distinguish between simultaneous transmissions, enabling multiple clients to transmit periodically without complete sequential access.
Solution Approach 2:
The patent changes key transmission parameters including phase shifts, cyclic shifts, and orthogonal signatures applied to preambles. These parameter changes allow multiple clients to transmit simultaneously with distinguishable signals, transforming the traditional single-client-at-a-time approach into a multi-client simultaneous transmission system.
3Reliability
If sequential transmission access is implemented to avoid interference, then transmission reliability is maintained, but transmission speed and capacity are reduced
Solution Approach 1:
The patent applies preliminary action by having clients transmit preambles with orthogonal signatures and cyclic shifts before actual data transmission. This preliminary phase establishes channel state information and interference patterns that the access point uses to manage subsequent data transmissions, ensuring reliability while enabling faster simultaneous data transfer.
Solution Approach 2:
The patent moves the problem from a single-dimensional sequential access model to a multi-dimensional solution using orthogonal signatures, phase shifts, and cyclic shifts. By adding these dimensional parameters to the transmission space, multiple clients can transmit simultaneously along different dimensions while maintaining reliability through the structured signal design.
Data Source
AI summary
A client device includes a processor and an antenna. The client device obtains an announcement that specifies a winning client of a channel contention competition; identifies a group association of the client device using an identity of the winning client; transmits a preamble modulated by an entry of a preamble interference nullification matrix, the entry is based on the group association; and transmits, after transmitting the preamble, a data transmission. The preamble is transmitted at the same time as a second preamble is transmitted by a second client device.