Modulation Techniques - ntuemc.tw
Prof. Tzong-Lin WuEMC LaboratoryDepartment of Electrical EngineeringNational Taiwan University2011/2/21Modulation Techniques1MW & RF Design / Prof. T. -L. Wu2011/2/21 Analog Modulation : AM, FM and PM. Modern wireless systems use digital Modulation . More spectrum efficient, less power required and error correction Better immunity to fading. Study the effect of noise of digital Modulation , the Modulation and & RF Design / Prof. T. -L. Wu2011/2 Analog modulation3MW & RF Design / Prof. T. -L. WuBecause the IF signal in a receiver contains noise from the antenna and receiver circuitry, as well as the desired signal, the characteristics of the demodulator play a critical role in the overall performance of the wireless modulation4MW & RF Design / Prof. T. -L. WuThe upper sideband is selected from the mixer output with a bandpassfilter, although the lower sideband could be selected, if that the demodulator LO is identical in frequency and phase with the modulatorLO; this is called a synchronous, or coherent, & RF Design / Prof.
2011/2/21 MW & RF Design / Prof. T. -L. Wu 11 A more realistic result is found by expressing the input noise power in terms of the power spectral density of the white noise at the input to the IF stage.
Download Modulation Techniques - ntuemc.tw
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: