For example, for a signal modulated with a linear modulation like AM ( amplitude modulation ), we can use a synchronous detector.
2.
This value is 20 % better than GSM . The major disadvantage with this type of linear modulation method is the power inefficiency, which translates into a heavier hand-held portable and, even more inconvenient, a shorter time between battery recharges.
3.
When consecutive symbols are transmitted over a channel by a linear modulation ( such as QAM, etc . ), the impulse response ( or equivalently the frequency response ) of the channel causes a transmitted symbol to be spread in the time domain.