When selecting a wireless transmission solution for drones or UAVs, customers often ask about OFDM vs COFDM, Pixhawk telemetry integration, and performance in obstructed environments. Here we answer the most common questions.

Table of Contents

Q1: Can TX900 be modified to use COFDM technology?

A: No, TX900 is based on OFDM with TDD (Time Division Duplex). It is optimized for low-latency video and bidirectional telemetry and cannot be converted to COFDM.

Q2: Why consider COFDM instead of OFDM?

COFDM is preferred when NLOS performance is critical, such as in urban areas, mountainous terrain, or obstructed environments. Its advantages include:

Strong diffraction and multipath resistance
Reliable video transmission in harsh RF conditions
High stability in challenging environments

Q3: OFDM vs COFDM – Key Differences

Feature	OFDM (TX900)	COFDM
System Complexity	Low	Higher
Latency	Low (real-time control)	Slightly higher
Best Environment	LOS / Semi-LOS	NLOS / Obstructed
Data + Video	Bidirectional telemetry & HD video	Video-centric; telemetry may need adaptation
Duplex	TDD	Usually FDD

Q4: COFDM Solutions for UAVs

If COFDM is needed, we recommend:

Vcan1886 Mini COFDM Module

FDD-based COFDM transmission
Video + data over Ethernet (RJ45)
Suitable for NLOS environments
View Product

Customized High-Power COFDM Options:

300–500 MHz COFDM IP RJ45 Transceiver, 10 W PA
View Product
336–554 MHz COFDM IP FDD Transceiver, 5 W PA
View Product

Notes:

Larger/heavier enclosures – less suitable for small UAVs
RS232 data output only; Pixhawk requires RS232-to-TTL conversion

Q5: How to choose between TX900 (OFDM) and COFDM?

Choose TX900 (OFDM) if:

LOS or lightly obstructed environment
Low-latency video and telemetry is required
UAV size and weight are limited

Choose COFDM if:

NLOS or harsh environment
Diffraction and multipath resistance are critical
Slightly larger hardware is acceptable

Q6: Integrating COFDM with Pixhawk

RS232-to-TTL conversion may be needed
Integration requires planning due to limited data ports
Works best when NLOS reliability is more important than minimal latency

Conclusion:
TX900 OFDM modules are ideal for lightweight UAVs in LOS conditions, delivering low-latency video and telemetry. COFDM solutions provide better NLOS performance, but may require larger hardware and additional integration effort for Pixhawk telemetry.