PHOTONIC ANALOGUE-TO-DIGITAL CONVERTER BASED ON WAVELENGTH DIVISION MULTIPLEXING TECHNIQUE

摘要

A photonic (Ph) analogue-to-digital (ADC) converter architecture based on the wavelength division multiplexing (WDM) technique used to provide compressed spectrum of the ultra wideband radio signals that are being used in a given pico-cell area for monitoring purposes is presented. The signal at the different points of the WDM Ph-ADC architecture is analyzed and discussed in detail. The advantages/disadvantages of the WDM architecture are identified and compared with its time division multiplexing (TDM) counterpart. It is shown that the WDM Ph-ADC architecture provides adequate time stretching of the wireless signals captured in a given pico-cell. This system enables relaxing the bandwidth requirements of the electrical ADCs used to digitize the wireless signals prior digital signal processing is applied for spectrum and transceivers localization monitoring. In addition, it is concluded that the WDM Ph-ADC architecture supports higher pulse repetition rates than the TDM Ph-ADC architecture being of special interest when a fast up-date of the radio channel monitoring is required.