Frequency Spectrum Management

Since the 2010 Presidential MOU instructs the Secretary of Commerce to develop a communications suite jointly with the Federal Communications Commission (FCC) through the National Telecommunications Information Administration (NTIA), management will change over the next 10 years I will do. Federal and non-federal spectra totaling 500 MHz are available for mobile and fixed wireless broadband applications. Spectral redistribution is nearly twice the commercial spectrum and should stimulate investment, economic growth and employment creation while supporting the growing demand for wireless broadband services by consumers and businesses (National Te)

Clear spectrum management policies are required to guarantee usage frequency reasonably, efficiently and economically. This should be implemented by regulatory agencies based on the existing legal and regulatory framework for managing the country's ICT. The spectrum can include three parts: frequency allocation, spectrum monitoring and spectrum execution. Communication licenses include conditions for protecting consumers, including billing methods, dispute resolution, consumer complaints mechanisms, price regulation, emergency services, mandatory services to consumers, and responsibility for service violations. Regulatory authorities need to create and publish a service provider's code of conduct to demonstrate the actions, responsibilities and responsibilities required by the ICT industry.

Figure 3-10 Time domain and frequency domain representation of three sine waves The frequency domain consists of two graphs, amplitude spectrum and phase spectrum. The amplitude spectrum is a graph showing which frequency exists at which frequency, and the phase spectrum is a graph showing the phase of each frequency component. The amplitude spectrum of a complex periodic signal is called a harmonic (also called partial sound). The fundamental frequency, in this case 200 Hz, is also known as the first harmonic, the 400 Hz component (2 π f 0) is called the second harmonic, the 600 Hz component (3 π f 0) is called the third harmonic, and so on. . The second panel in Figure 3-11 shows a complex periodic signal with a basic period of 10 ms, so the fundamental frequency is 100 Hz. Harmonic spectra associated with this signal therefore indicate energies such as 100 Hz, 200 Hz, 300 Hz, 400 Hz, 500 Hz.

And convert it to the fundamental frequency (400 Hz), you can judge that the signal will be 400, 800, 1200, 1600 etc. But how do you know the magnitude of each frequency component? How do you know the stage of each component? The answer is that you can not simply identify the amplitude or phase of harmonics by checking the signal or simply measuring the time domain signal using a ruler. We will soon see a technique called Fourier analysis. It determines the amplitude and phase spectrum of every signal. Also, you can see that the inner ear of humans and many other animals developed technologies that, in a sense, produce a neural representation comparable to the amplitude spectrum. Also, there is no similar technique for deriving the expression corresponding to the phase spectrum in the ear. I will return to this later