Implementation Of Communication Systems

EE 340: Communications Laboratory, Prof. Jayakrishnan Nair

1. Practical Modulation Of RF signals

Performed practical analysis of analog carrier modulation schemes (DSB, DSB-SC, and SSB) using an IQ modulator board and AFG by observing the received spectrum using GNU Radio and a dongle. Verified the effects of of amplitude and phase imbalances in Side Band Suppression (SSB) by varying the amplitude and phase differences between I and Q signals.

2. Design Of Equalization Filter

Implemented equalization filter design to negate the effect of ISI (Inter Symbol Interference) on the digitally transmitted message suffering from multipath reflection. Formulated a relation between the z-transform of the received signal and the transmitted signal to efficiently manage delays, and used this relation to design a suitable inverse-filter for equalization.

3. End-to-End Digital Communication

Evaluated the performance of Costas Loop and Viterbi-Viterbi algorithms in discrete-time for phase and frequency offset removal in incoming signal 8-PSK using GNU Radio. Performed end-to-end transmission as well as reception of text files as a message using differential coding to handle unintentional inversion of bits in the binary waveform.