# Microwave Radio System Gain

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MICROWAVE RADIO SYSTEMS GAIN System Gain * Gs is the difference between the nominal output power of a transmitter (Pt) and the minimum input power to a receiver (Cmin) necessary to achieve satisfactory performance; * Must be greater than or equal to the sum of all gains and losses incurred by a signal as it propagates from a transmitter to a receiver * In essence, system gain represents the net loss of a radio system, which is used to predict the reliability of a system for a given set of system parameters. * Ironically, system gain is actually a loss. * Losses are much higher than the gains. * Therefore, the net system gain always equates to a negative dB value (i.e., a loss) * Because system gain is…show more content…
This threshold fundamentally limits the noise immunity of various types of non-linear modulation techniques CARRIER-TO-NOISE VS SIGNAL-TO-NOISE RATIO Carrier-to-Noise Ratio * In communications, the carrier-to-noise ratio, often written CNR or C/N, is a measure of the received carrier strength relative to the strength of the received noise. High C/N ratios provide better quality of reception, and generally higher communications accuracy and reliability, than low C/N ratios. * Carrier to noise ratio is the ratio of the carrier signal power to the noise power in some specified channel, usually expressed in decibels (dB). For the analog channels the noise is assumed flat and the result of thermal and amplifier noises. Carrier-to-Noise Ratio (mathematical definition) * Engineers specify the C/N ratio in decibels (dB) between the power in the carrier of the desired signal and the total received noise power. If the incoming carrier strength in microwatts is Pc and the noise level, also in microwatts, is Pn, then the carrier-to-noise ratio, C/N, in decibels is given by the formula: * C/N = 10 log10(Pc/Pn) * Engineers specify the C/N ratio in decibels (dB) between the power in the carrier of the desired signal and the total received noise power. If the incoming carrier strength in