Need for Modulation Recognition
There are so many communication signals all available with different types of modulation and different frequencies. It is necessary to identify and closely monitor these signals for few applications. Surveillance and military operations require classification of modulation whether analog or digital modulation technique because it is necessary to know the type of incoming signal. How to observe and identify modulated signals is necessary to know about valuable information. The recognizers help to distinguish the signal in presence of (AWGN) along with presence of other signals. The process of recognition is the first step in demodulating the original signal.
Modulation recognition starts with modulation feature extraction to obtain unique information related to amplitude, phase, and frequency. Then, feature recognition is applied by using logic analysis to match features to known templates, or using statistical analysis to find a solution based on probabilities. The automatic recognition of the modulation format of a detected signal is a major task of an intelligent receiver, with various civilian and military applications. Without any knowledge about incoming signal and its parameters, blind identification of modulation technique is difficult. Proper demodulation of the incoming signal takes place with the help of automatic modulation recognition without knowing the modulation scheme beforehand. Automatic modulation recognition is an emerging topic for software-defined radios.
Furthermore, blind recognition of the modulation format of the received signal is an important problem in software defined radio (SDR). The Software Defined Radio (SDR) is widely used in military and commercial communication applications. Meanwhile, the requirement of identifying the modulation format of the incoming signal is necessary for designing intelligent wireless systems that can be used in different applications.