Radio Spectrum Occupancy Analysis And Signal Modulation Recognition

With the rapid development of wireless communications and Internet technology, and the4G technology is being widely used in our country, more and more radio services are requesting the originally limited radio spectrum. Radio frequency spectrum as a special kind of natural resource, is very precious, this resource, like other natural resources such as oil, natural gas, coal, etc., is extremely limited resource although it’s not consumptive. It also can be shared which results in all kinds of interferences. Therefore, it has become a strategic resource attracting a lot of contention and protection from the countries all over the world which is directly related to the interests of all countries in the economic, political, military and other aspects. Nowadays, the spectrum shortage problem has become primary problem of the development of radio communications for many countries. Traditional spectrum allocation and management policies have failed to meet the requirements of the development of today’s society. On the one hand, most of the allocated spectrum used sporadically, and showing regional differences; on the other hand, a large number of spectrum allocated in some places are not actually used most of the time. In order to master the usage of the spectrum with a real time vision, spectrum monitoring and signal recognition technology has been receiving more and more attention from many organizations.Lately, with the emergence and development of high-bandwidth wireless communication technologies with a relatively large coverage such as CDMA EV-DO, WIMAX, satellite broadband access, etc., the communication service of aviation passengers is becoming possible. In this paper, deeply research and analysis of the spectrum occupancy ha, e been launched for this new scenario of air-ground communication. On this basis, an in-depth research on the signal modulation recognition has been done, and extremely focusing on the M-QAM modulation recognition technology. The main work is as follows:1) From the view of automation, a spectrum monitoring system is designed and implemented with successful accomplishment of remote-control. Through the monitoring near the airport of Beijing, Shanghai, Chengdu and Xi’an, a big amount of sampling data was gained. The data then was processed to graphing the differences among those places and the spectrum occupancy of each place.2) For the past research on M-QAM modulation identification signals are in poor performance when the SNR is low, what’s more are not systematically enough. This paper starts from the M-QAM signal generation, and then through the research on the signal pre-processing, feature extraction and classifier designation, proposed a modulation recognition method with high accuracy but low complexity. Simulation tests are conducted to verify it.