Wireless Optical Transceiver M-PAM Bandwidth Adaptation
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Solution Overview
Problem
Current wireless optical communication systems face limitations in bandwidth utilization and mobility due to the lack of mature wireless optical modules supporting higher-order modulation methods, and existing light source lamps are susceptible to position and angle changes, leading to non-linear light intensity reception and complexity in clock data recovery.
Innovation Solution
A wireless optical communication data transmission apparatus comprising a transmit module that converts serial data into multipath control signals and a receive module with a peak value detector and comparator group, which dynamically adjusts the threshold voltage to improve bandwidth utilization and adapt to varying communication positions, using a transmission gate, pulse shaping filter, and error detection for reliable data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher-order modulation methods (M-PAM) are used to increase communication rates, then bandwidth utilization is improved, but the complexity of the system increases due to lack of mature wireless optical modules
Solution Approach 1:
The transmitter divides serial data into multiple parallel data streams using a serial-to-parallel converter, with each stream modulating a separate light source bead. This segmentation allows M-PAM modulation to be implemented by controlling different numbers of parallel light beads, achieving higher-order modulation without requiring complex single-channel modulation circuits.
Solution Approach 2:
The system uses the inherent characteristics of multiple light source beads to naturally implement M-PAM modulation. By simply controlling the number of lit beads rather than using complex modulation schemes, the system achieves high-order modulation while maintaining relative simplicity in the driver circuitry.
2Productivity
If multiple light source beads are used for PAM modulation, then higher communication rates are achieved, but different delays in lighting and extinguishing cause limitation to light source modulation bandwidth
Solution Approach 1:
The driver circuit is designed to simultaneously control the switching of multiple light source beads through a unified clock signal. By pre-synchronizing the switching timing and using parallel control paths, the system eliminates cumulative delays that would occur in sequential control, thereby maintaining high modulation bandwidth despite using multiple beads.
3Adaptability or versatility
If the receiver position and angle change, then mobility is improved, but the received light intensity becomes non-linearly proportional to the quantity of lit light beads, increasing receiver complexity
Solution Approach 1:
The receiver employs a feedback mechanism where the detected optical signal strength is used to dynamically adjust the reference voltage for threshold comparison. This feedback loop compensates for variations in receiver position and angle, maintaining accurate threshold determination despite changes in received light intensity, thereby enabling mobility without proportionally increasing receiver complexity.
Solution Approach 2:
The system changes the reference voltage parameter dynamically based on the received signal conditions. By adjusting the reference voltage to match the actual received light intensity levels, the system maintains accurate threshold detection even when the receiver position or angle changes, allowing mobility while keeping the receiver design relatively simple.
4Device complexity
If a fixed reference threshold voltage is used in the clock data recovery circuit, then the circuit structure is simplified, but the receiving position becomes fixed and the circuit is susceptible to external interference
Solution Approach 1:
The reference voltage in the clock data recovery circuit is changed from a fixed value to a dynamically adjustable parameter. The reference voltage is now derived from the actual received signal through a peak detector and voltage divider, allowing the circuit to automatically adapt to different receiving positions and signal conditions. This dynamic adjustment maintains circuit simplicity while significantly improving adaptability and resistance to external interference.
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 solution enables high-speed, low-delay M-PAM signal transmission, efficiently utilizing bandwidth, reducing system complexity, and enhancing the flexibility of communication positions, thereby overcoming the limitations of fixed-point communication in wireless optical systems.
Implementation Method 1
convert the electrical signal into an optical signal, and transmit the optical signal to the receive module
Implementation Method 2
convert the received optical signal into the electrical signal
Data Source
AI summary
The present invention provides a wireless optical communication data transmission apparatus and method, including a transmit module and a receive module, where the transmit module includes a transmission gate, and the transmit module is configured to convert serial data into multipath control signals to control the transmission gate to output an electrical signal, convert the electrical signal into an optical signal, and transmit the optical signal to the receive module; and the receive module includes a peak value detector and a comparator group, and the receive module is configured to convert the received optical signal into the electrical signal and output the serial data after threshold determination by the comparator group, where the peak value detector provides a reference voltage to the comparator group according to the received electrical signal, and the comparator group performs voltage division according to the reference voltage to determine a threshold.