How do digital and analog two-way radios connect and talk?

Date:Jul 29, 2020

Digital and analog signal conversion

Are digital two-way radio in the market now compatible with traditional two-way radio? Can you guarantee that the communication between the digital two-way radio and the analog two-way radio will not be affected?

The two-way radio in digital mode and analog mode cannot talk even if the frequency is the same. Take a two-way radio that conforms to the DMR standard, assuming that one two-way radio is in the digital channel, and the other is transmitting on the analog channel. The digital two-way radio can only see and receive. The green light is on, there is no way to demodulate. And the analog two-way radio will only have a sudden sound.

Many digital two-way radio have digital-analog compatibility written on their function introductions. What is this digital-analog compatibility! In fact, it is impossible to receive digital and analog signals at the same time on the same channel, but the two-way radio has the function of receiving analog and digital signals.

Digital-to-analog compatible two-way radio can choose two different channels, write digital or analog frequency points respectively, and then turn the knob to receive digital or analog signals, so that both digital and analog signals can be received.

It is technically feasible for two-way radio to receive digital and analog frequencies on the same channel. The current relatively popular solution is to convert and sample analog and digital signals after frequency conversion, and then connect to software radio (SDR), if it can be solved The synchronization sequence code is resolved in accordance with the digital, if the sub-tone signal can be resolved, it is resolved in accordance with the analog. However, the bandwidth of analog signals and digital signals are not the same, which will affect performance and cause interference, which is not practical.SDR
If you use a repeater for relay, it is much more reliable to connect the digital signal and the analog signal to each other, and then compile the analog into a digital group.