Prototype of a Pulse-Frequency Modem for Transmitting Information over Power Supply Networks

The article presented the formulation of the development task, conceptual considerations and a block diagram of a modem and codec for transmitting information over household power supply networks to control smart home devices and receive telemetry from sensors. Initially, it was assumed that the amount of data for such devices is small and amounts to a maximum of 3 bytes per communication session. The modem is supposed to work on the scale of one apartment or private house, which imposes requirements on the power of the transmitter (in order to avoid affecting nearby similar networks). With this limitation, the problem of using various methods to increase the noise immunity of the data transmission line, in particular the use of noise-proof coding, becomes urgent. The implementation of this system is assumed with the help of simple and inexpensive circuit and software solutions. Based on the considerations from the article, a prototype modem and software were developed that generates, transmits, receives and decodes packets using noise-proof coding and correlation detection of the pilot signal integrated into the packet structure. The experiments have confirmed the required reliability of the modem and the applicability of this approach to solve the problem of transmitting information between smart home devices on the required scale.