Frequency-Hopping Wireless Transmitter for IoT Collision Reduction

The patent extends random medium access from single-frequency ALOHA to multi-dimensional frequency-hopping ALOHA. Nodes hop across multiple frequency sub-bands according to pseudo-random sequences, creating diversity in the time-frequency-power space. This allows significantly higher system load capacity while maintaining the simplicity and power efficiency of random access, as collisions in one frequency hop do not necessarily result in complete message loss.

The patent changes the modulation parameters from fixed ultra-narrowband to variable frequency-hopping narrowband. By dynamically changing frequency parameters across multiple hops and using error-correction coding, the system can tolerate higher collision rates while maintaining reliable communication, thereby increasing system load capacity beyond the 1% limitation of traditional ultra-narrowband networks.

The patent segments the available frequency band into multiple narrow sub-bands and distributes the message across these segments through frequency hopping. Each sub-band carries a portion of the encoded message, and the receiver reconstructs the original message by combining segments from multiple frequency hops. This segmentation approach provides interference resistance while keeping individual transmitter and receiver components relatively simple.

The patent designs universal frequency-hopping narrowband transceivers that can operate across multiple frequency sub-bands using the same hardware architecture. The same transmitter circuitry and receiver processing are used regardless of which frequency sub-band is currently active, reducing device complexity compared to having dedicated circuits for each frequency. The system achieves multi-functionality through software-controlled frequency hopping rather than hardware multiplication.