Distributed Antenna MIMO Hybrid Coupler Signal Distribution
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Solution Overview
Problem
Current distributed antenna systems cannot effectively utilize MIMO technology, leading to signal degradation and limited bandwidth due to the inability to transmit all MIMO signals from multiple remote units, resulting in performance impairments and restricted data throughput.
Innovation Solution
Incorporating a hybrid coupler, specifically a 90° 3dB hybrid coupler, to cross-couple MIMO signals to all remote units, ensuring equal power distribution and enabling simultaneous transmission of MIMO and SISO signals, thus overcoming the 'near-far problem' and allowing dynamic switching between SISO and MIMO modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MIMO signals are transmitted from multiple remote units, then system capacity and data throughput are improved, but signal degradation and collisions occur due to inability to coordinate multiple remote units simultaneously
Solution Approach 1:
The patent segments the MIMO signal transmission by assigning different remote units to transmit different spatial streams. Specifically, a first remote unit transmits a first MIMO signal while a second remote unit transmits a second MIMO signal, allowing the system to exploit spatial diversity and multiply the effective data throughput without causing signal collisions at the receiver.
Solution Approach 2:
The patent introduces a spatial dimension to the transmission system by utilizing multiple geographically separated remote units. Each remote unit transmits on the same frequency but from a different location, creating spatially independent channels. This dimensional expansion allows simultaneous transmission of multiple data streams that would otherwise collide in a single-antenna system.
2Productivity
If all MIMO signals are transmitted to all remote units, then full MIMO capability is achieved, but power distribution becomes unbalanced causing the 'near-far problem'
Solution Approach 1:
The patent applies local quality by configuring each remote unit to transmit only specific MIMO signals rather than all signals. A first remote unit is configured to transmit a first MIMO signal while a second remote unit transmits a second MIMO signal, creating locally optimized transmission patterns that balance power distribution and eliminate the near-far problem while maintaining full MIMO capability.
3Device complexity
If a single remote unit transmits all signals, then system complexity is reduced, but bandwidth is constricted to the speed of one receiver
Solution Approach 1:
The patent segments the transmission function across multiple remote units, where each unit handles specific MIMO signals. This segmentation increases bandwidth capacity because multiple receivers can simultaneously process different spatial streams, overcoming the bottleneck of a single receiver's processing speed while the modular configuration keeps system complexity manageable.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances data throughput by ensuring balanced received power levels from multiple remote units, enabling reliable MIMO operation and equalizing performance between data streams, thereby improving overall system capacity and reliability.
Implementation Method 1
Incorporating a hybrid coupler, specifically a 90° 3dB hybrid coupler, to cross-couple MIMO signals to all remote units, ensuring equal power distribution
Data Source
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AI summary
The invention relates to a distributed antenna system (10, 40, 100, 220, 251, 258) comprising: at least one master unit (16, 46, 260); a plurality of remote units (12, 42, 262) communicatively coupled with the at least one master unit (16, 46, 260) and distributed to provide coverage within a service area, each of the plurality of remote units (12, 42, 262) remotely located from the at least one master unit (16, 46, 260) and other remote units (12, 42, 262) of the plurality of remote units (12, 42, 262); a coupler element (52, 274) coupled to receive a plurality of multiple-input and multiple-output (MIMO) signals, the plurality of MIMO signals including at least a first MIMO signal (CHI) and a second MIMO signal (CH2), the coupler element (52, 274) configured to: introduce a phase shift in a first portion of the first MIMO signal (CHI) to generate a first phase shifted portion of the first MIMO signal (CHI); combine the first phase shifted portion with a second portion of the second MIMO signal (CH2) to generate a combined MIMO signal; and present the combined MIMO signal at a first output port (3, 4) of the coupler element (52, 274); at least one antenna (14) coupled with each of the plurality of remote units (12, 42, 262) and configured to receive the combined MIMO signal for transmission.