Desensitization (telecommunications)
Encyclopedia
For telecommunications, desensitization is a form of electromagnetic
interference
where a radio receiver is unable to receive a weak radio signal that it might otherwise be able to receive when there is no interference. This is caused by a nearby transmitter with a strong signal on a close frequency
, which overloads the receiver and makes it unable to fully receive the desired signal.
Typical receiver operation is such that the Minimum Detectable Signal (MDS) level is determined by the thermal noise of its electronic components. When a signal is received, additional spurious signals are produced within the receiver due to it not being a truly linear device. When these spurious signals have a power level that is less than the thermal noise power level, then the receiver is operating normally. When these spurious signals have a power level that is higher than the thermal noise floor, then the receiver is desensitized. This is because the MDS has risen due to the level of the spurious signals. Spurious signals increase in level when the received signal strength increases.
When an interfering signal is present, it can contribute to the level of the spurious signals. Stronger interference generates stronger spurious signals. The interference may be at a different frequency that the signal of interest, but the spurious signals caused by that interference can show up at the same frequency as the signal of interest. It is these spurious signals that degrade the ability of the receiver by raising the MDS.
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
interference
Interference (communication)
In communications and electronics, especially in telecommunications, interference is anything which alters, modifies, or disrupts a signal as it travels along a channel between a source and a receiver. The term typically refers to the addition of unwanted signals to a useful signal...
where a radio receiver is unable to receive a weak radio signal that it might otherwise be able to receive when there is no interference. This is caused by a nearby transmitter with a strong signal on a close frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
, which overloads the receiver and makes it unable to fully receive the desired signal.
Typical receiver operation is such that the Minimum Detectable Signal (MDS) level is determined by the thermal noise of its electronic components. When a signal is received, additional spurious signals are produced within the receiver due to it not being a truly linear device. When these spurious signals have a power level that is less than the thermal noise power level, then the receiver is operating normally. When these spurious signals have a power level that is higher than the thermal noise floor, then the receiver is desensitized. This is because the MDS has risen due to the level of the spurious signals. Spurious signals increase in level when the received signal strength increases.
When an interfering signal is present, it can contribute to the level of the spurious signals. Stronger interference generates stronger spurious signals. The interference may be at a different frequency that the signal of interest, but the spurious signals caused by that interference can show up at the same frequency as the signal of interest. It is these spurious signals that degrade the ability of the receiver by raising the MDS.