digital communications

EE352- Digital Communication Exercise [1] Name: ID: Date: 1- Complete the following figure (plot PAM , PWM, and PPM) using the pulse 𝑝(𝑡): 5 𝑝(𝑡) 1 𝑚(𝑡) -5 𝜏 𝑥𝑃𝐴𝑀 (𝑡) 𝑥𝑃𝑊𝑀 (𝑡) 𝑥𝑃𝑃𝑀 (𝑡) 𝑡 2- Check if the following pulses are Nyquist pulse or not: 𝑝(𝑡) 𝑝(𝑡) 1 𝑝(𝑡) 1 1 𝑡 −2𝑇 𝑡 −4𝑇 5 2𝑇 —————— 4𝑇 5 𝑡 −2𝑇 ———————— ———————– 𝑝(𝑓) 𝑝(𝑓) 𝑇 𝑇 𝑓 𝑓 −1 4𝑇 𝑇 −𝑇 1 4𝑇 ————————— −1 𝑇 1 𝑇 ———————– 2𝑇 3- 𝑓 𝑓 𝑓 4- A communication system is using PAM to transmit a three-character message “H2O”. After converting each character in the message into its 7-bit ASCII representation and interpreting it as a two’s complement representation, we see that the three symbols corresponds to three decimal numbers: -56, 50, -49. These numbers are denoted by 𝑚[0], 𝑚[1], and 𝑚[2], respectively. Assume 𝑚[𝑛] = 0 for other values of 𝑛. Recall that the PAM signal is constructed from the discrete-time message 𝑚[𝑛] via a. Plot 𝑥𝑃𝐴𝑀 (𝑡) when the following pulse is used and 𝑇𝑠 = 1. b. Plot 𝑥𝑃𝐴𝑀 (𝑡) when the following pulse is used and 𝑇𝑠 = 0.4.