Wireless Terminal Delay Module for Synchronized Uplink Access
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Solution Overview
Problem
Existing wireless communication technologies, such as WiMAX, face challenges in providing adequate coverage and capacity to sparsely distributed user terminals in remote areas, with current systems requiring high bandwidth and power levels, leading to increased costs.
Innovation Solution
A wireless communication system that synchronizes multiple user terminals in time and frequency, using directional antennas and a delay module to ensure simultaneous symbol transmission, allowing for effective separation of uplink data streams at the access point, thereby reducing power consumption and increasing coverage while maintaining acceptable data rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If WiMAX operates at carrier frequency above 2 GHz with access point antenna height less than 30 m, then spectral efficiency is improved (2 to 5 bits/sec/Hz), but coverage distance is limited to less than 10 kilometres
Solution Approach 1:
The patent changes the carrier frequency parameter from above 2 GHz to below 1 GHz (specifically 450-960 MHz), which fundamentally alters the propagation characteristics to enable longer distances while maintaining reasonable spectral efficiency through optimized modulation and multiple antenna techniques
2Length of moving object
If transmit power is increased from access point and user terminals to overcome coverage limitations, then coverage distance is improved, but system cost increases
Solution Approach 1:
The patent combines multiple transmit antennas at the access point with multiple receive antennas at user terminals to create a MIMO system, merging spatial dimensions with frequency diversity to achieve coverage extension without proportionally increasing transmit power
3Productivity
If WiMAX provides simultaneous access to thousands of users with data rates of 1 to 20 MBits/s, then capacity requirement increases, but available bandwidth at carrier frequency above 2 GHz is insufficient
Solution Approach 1:
The patent introduces spatial dimension through multiple antennas and spatial multiplexing, transforming the single-frequency-channel limitation into multi-stream parallel transmission, effectively increasing capacity without requiring proportional bandwidth increases
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
The system achieves efficient bidirectional data transmission with improved coverage and capacity, reducing power consumption and costs by utilizing directional antennas and precise timing synchronization, enabling simultaneous access for multiple users with acceptable data rates.
Implementation Method 1
Because the system relies predominantly on line-of-sight transmission, the user terminal antennas are directional
Implementation Method 2
the delay is computed by the delay module using a propagation delay between said fixed user terminal and said fixed access point
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
Disclosed is a user terminal for wireless communication with a remote access point, the user terminal comprising: a mapping module adapted to map one or more input data bits to an uplink symbol; a delay module adapted to apply a delay to the uplink symbol; a transmit module adapted to modulate the delayed symbol into a frequency channel; and a directional antenna oriented along a dominant path to the access point, the antenna being adapted to transmit the modulated symbol to the access point, wherein the delay is chosen such that the transmitted symbol arrives at the access point simultaneously with a further symbol modulated into the frequency channel and transmitted by a further user terminal.