Interference
Interference is another transmission disturbing the operation of the receiver. In co-channel interference the disturbing transmission is exactly on your channel; in adjacent channel interference the part of a strong transmission on the neighbouring channel that leaks through the filter causes the problem. The two have different solutions, and diagnosis starts with this distinction.
In co-channel interference two transmissions overlap on the same frequency. A filter does not help; the solution is to change channel, move to a frequency hopping protocol, or find and remove the disturbing source.
In adjacent channel interference the disturbing transmission is on the neighbouring channel but its power is very high. Because the receiver filter is not infinitely sharp, part of it leaks in. The measures that work here are different:
- Physically moving the antenna away from the disturbing source; the dB gained through distance counts directly.
- Creating a polarisation difference; in suitable geometry it gives measurable suppression.
- Using a receiver with narrower bandwidth and better filtering.
Typical sources in the field include other remote controls working in the same band, radios, wireless data links and strong transmitters nearby. The first step in diagnosis is to watch whether the link recovers during a period when the disturbing source is not transmitting.
Context where this term is used: 433 MHz or 2.4 GHz?