Lab-7: QPSK Modulation & Demodulation Quadrature phase shift keying (QPSK) modulated signal includes two independent and orthogonal BPSK signals. The modulated signal can be written as: i,()= cos (@)t +*/4)= Cos a, - cos ot- sin @t 1 1,(1) = cos (@t+3x/4) =- V2 sin ot i,(1) = cos (@1+5n /4)=- cos o1+ TE V2 VE sin ot 1 i,(1) = cos (@t+7/4) =cos o1+sin ot %3D In QPSK, unlike BPSK, there are four different phase values, such as t/4, 3n/4, 5n/4, and 7n/4. Thus, M = 4 for QPSK. A. QPSK BandPass Modulated Signal Model: Construct the below block diagrams for QPSK signal modulator and demodulator, respectively. Serial- to Paralel block is not available in the library. The carrier frequency is 5 Hz and also T, duration is 1. Serial-to Paralel block divides bit stream into I and Q channels. Then I channel is multiplied with Cosine carrier and Q channel is multiplied with Sine carrier. Follow the steps below in order and answer the questions. juate Nmintion cwficem Lpote tipl Caverter KOPSH Sgnal Tahar Lpol t ary Cenverter Sera OPSK Ma Synal O chinel johane nd OPSK dala wwti Figure 1 QPSK Modulator Block Required Blocks 1. Benoulli Binary Generator 2. Sine Wave for carrier signal 3. Gain 4. Sum 5. Multiplier 6. Analog filter 7. Inequality 8. Scope 9. Unipolar to Bipolar converter 10. Switch 11. D-Latch Flip-Flop 12. Delay 13. Clock 2. In the right Scope, QPSK modulated signal is observed. Please make comments on the I channel, Q channel, and QPSK signal changes. Does the QPSK signal include both I & Q channel changes? Fill the table below. Time Interval 1-2sec 2-3 sec 3-4 sec 4-5 sec 5-6 sec 6-7 sec Phase changes on I channel Phase changes on Q channel Phase changes on QPSK signal