Also referred to as quota control, it is a method of selecting subjects for a study. The subjects are already chosen for specific characteristics such as age, sex, education, etc.The quota sampling assures the proper proportion of these traits in the group.lso referred to as quota control, it is a method of selecting subjects for a study. The subjects are already chosen for specific characteristics such as age, sex, education, etc.
In contrast, a broadband signal is a signal which does not occupy the lowest range, but instead a higher range, 1MHz to 3MHz, for example. A wire may have only one baseband signal, but it may hold any number of broadband signals, because they can occur anywhere in the spectrum.
A secondary telecommunications channel that resides within the main channel (a carrier within a carrier). A type of multiplexing, the subcarrier is a modulated carrier signal at a lower frequency that is combined with the main carrier signal running at a higher frequency. Many Uses Color TV signals were added in a subcarrier to black and white signals in order to maintain backward compatibility with monochrome TV sets.