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COFDM Classification in Wireless Transmission

COFDM (Coded Orthogonal Frequency Division Multiplexing) is one of the most reliable transmission technologies for UAVs, unmanned vehicles, and wearable systems. Its strong anti-multipath capability, support for NLOS (non-line-of-sight) transmission, and adaptability across wide frequency ranges make it a cornerstone in wireless video, audio, and data links.

In UAV wireless transmission, COFDM systems can be classified according to several standards:

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1. By Device Type

• COFDM Transmitters

  • Devices dedicated to sending video, audio, and data streams.

  • Typical use: UAV airborne modules, body-worn transmitters, vehicle-mounted transmitters.

• COFDM Receivers

  • Devices for decoding and outputting signals (HDMI, CVBS, IP, or recording).

  • Common in ground stations, mobile command centers, or monitoring systems.

• COFDM Transceivers

  • Provide bidirectional communication: video downlink + telemetry or control uplink.

  • Essential for advanced UAV applications requiring integrated command and monitoring.

  • The uplink and downlink can be set to different operating frequencies.

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2. By Transmission Direction

• Unidirectional COFDM

  • One-way transmission, e.g., video from UAV to ground.

  • Lower complexity and cost, often used for FPV video or broadcast.

• Bidirectional COFDM

  • Two-way link supporting both video downlink and telemetry/control uplink.

  • Enables full integration of video, flight data, and control feedback in one system.

• Unidirectional Video and Bidirectional Data

  • One-way video transmission and two-way data transmission, mainly used for ground robots and remote control vehicles.

• COFDM Relay / Repeater between Transmitter and Receiver

  • A COFDM relay receives, amplifies, and retransmits the signal between the transmitter and receiver to enhance its strength and coverage.

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3. By Transmission Content

• COFDM Video Transmitters

  • Focused on sending live video from UAV cameras.

• COFDM Video + Telemetry Data Transmitters

  • Combine real-time video with GPS, sensor, and flight control data.

  • Common in surveillance drones, inspection UAVs, and defense applications.

• COFDM Audio Transmitters

  • Designed for voice communication or audio-only streams.

  • Can be used standalone or in parallel with video systems.

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4. By Signal Input Interface

• HDMI Input COFDM Transmitters

  • Connect directly to HD/4K cameras with HDMI output.

• SDI Input COFDM Transmitters

  • Professional-grade, supporting HD-SDI/3G-SDI cameras for broadcast and cinema drones.

• CVBS Input COFDM Transmitters

  • Legacy analog video interface (AV).

  • Used in cost-sensitive or backward-compatible UAV systems.

• AHD Input COFDM Transmitters

  • Compatible with Analog High Definition cameras (720p/1080p).

  • Often used in security and industrial UAV setups.

• Network (IP) Input COFDM Transmitters

  • Accept IP streams from network cameras or encoders.

  • Flexible for UAVs carrying thermal imagers, AI vision modules, or IP PTZ cameras.

• Audio Input COFDM Transmitters

  • Dedicated for microphone/line-in sources for real-time voice communication.

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5. By Frequency Band

• Low-to-Mid Band COFDM (170–860 MHz)

  • Strong penetration and long-distance coverage.

  • Useful for NLOS UAV operations in urban or forest environments.

• High Band COFDM (860 MHz–6 GHz)

  • Higher bandwidth for HD/4K video.

  • Requires frequency down-converters for cofdm video receiver.

  • Common ranges: 1.2 GHz, 2.4 GHz, 3.3GHz, 5.8 GHz.

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6. By Form Factor / Housing

• Mount Metal box – CNC customize, 1U or 2U chassis for ground stations or integrated command centers.

• Module-Only – customers provide their own enclosure, PA, and cooling solutions.

7. Customization Options

• PA (Power Amplifier) – built-in or external
• How many watts of amplifier – 1-watts, 2-watts, 5-watts, 10-watts, 20-watts, 50-watts

• Filter – low-pass, band-pass, or custom filters; can be applied to transmitters, receivers, or both.

• Enclosure Type – 1U, 2U rack, or custom housings for UAV/vehicle/wearable integration

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8. By Deployment Platform

• UAV-Mounted COFDM Transmitters

  • Compact, lightweight, optimized for airborne use.

  • Key features: low power consumption, vibration resistance, efficient cooling.

• UGV-Mounted COFDM Transmitters

  • Installed on unmanned ground vehicles or robots.

  • Focus on long endurance and high-penetration communication.

• Body-Worn COFDM Transmitters

  • Designed for soldiers, journalists, or rescue teams.

  • Provide live video/audio streaming while being mobile.

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Summary

COFDM in UAV wireless transmission can be classified by:

• Device type (transmitter, receiver, transceiver),

• Directionality (one-way vs. two-way),

• Transmission content (video only, video + telemetry, audio only),

• Input type (HDMI, SDI, CVBS, AHD, IP, audio),

• Frequency band (170–860 MHz vs. 860 MHz–6 GHz),

• Customization Options ( Power Amplifier, Filter, Enclose Type),

• Deployment platform (UAV, UGV, body-worn).

This layered classification makes COFDM highly adaptable across industries: UAV aerial surveillance, broadcast, defense, emergency response, robotics, and wearable communication systems.