Rattlegram - SMS via audio! APK

COFDMTV (Coded Orthogonal Frequency-Division Multiplexing Television) is a sophisticated technology that leverages the principles of COFDM (Coded Orthogonal Frequency-Division Multiplexing) to deliver high-quality broadcast signals.

This system boasts several technical attributes that improve its performance and dependability:

- OFDM symbols with a duration of 160 ms

- Sub-carrier spacing of 6.25 Hz

- A guard interval of 1/8

- Differentially encoded PSK (phase-shift keying) modulation

- Systematic polar codes for effective forward error correction

Modes 14, 15, and 16

- COFDMTV currently operates in several modes, specifically Modes 14, 15, and 16.

- Each mode offers distinct configurations for transmission, allowing for adaptability to the specific needs of the broadcasting environment.

Diverse Configurations

- The system can transmit payloads using various configurations, including SPC(2048, 1392), SPC(2048, 1056), or SPC(2048, 712).

- These configurations employ CRC32C (Cyclic Redundancy Check) supported SCL (Successive Cancellation List) decoding, enhancing error detection and correction during signal processing.

Low Bandwidth Requirement

- COFDMTV efficiently transmits data with a bandwidth requirement of just 1600 Hz.

- This low bandwidth necessity facilitates cost-effective broadcasting and enables signal transmission in frequency-limited environments.

- When sending data packets of sizes 85, 128, or 170 bytes, the system can complete the transmission in about one second, especially when leading noise and advanced header features are turned off.

- This efficiency makes COFDMTV an excellent choice for television broadcasting, particularly in situations where quick data transfer is crucial.

FAQ

Q: What are the different modes of COFDMTV?

A: COFDMTV currently operates in several modes, specifically Modes 14, 15, and 16. Each mode offers distinct configurations for transmission, allowing for adaptability to the specific needs of the broadcasting environment.

Q: What is the bandwidth requirement for COFDMTV?

A: COFDMTV efficiently transmits data with a bandwidth requirement of just 1600 Hz. This low bandwidth necessity facilitates cost-effective broadcasting and enables signal transmission in frequency-limited environments.

Q: How efficient is COFDMTV in terms of data transmission?

A: COFDMTV is highly efficient in data transmission. When sending data packets of sizes 85, 128, or 170 bytes, the system can complete the transmission in about one second, especially when leading noise and advanced header features are turned off. This efficiency makes COFDMTV an excellent choice for television broadcasting, particularly in situations where quick data transfer is crucial.

Version History

v1.16——16 Apr 2025

Transmit short text messages over COFDMTV encoded audio signals Download the latest version of Rattlegram - SMS via audio! to enjoy new features and updates immediately!

*1.16

- improved robustness

- updated libs and tools

*1.15

- added configurable repeater delay

- added configurable repeater debouncing

- internal improvements

- updated libs and tools

*1.14

- added sub-menu for dangerous operations:

- added option to delete all messages

- added option to enable ultrasonic transmissions