Assignment:
A direct-sequence spread-spectrum system with a processing gain of 20 dB uses OPSK modulation for transmitting data. A rate error-correcting code is used, and the required bit-error probability is 10-5. Assuming perfect synchronization. What is the minimum value of Ech/I0 and Ec/0 needed to support these requirements?
Provide complete and step by step solution for the question and show calculations and use formulas.