Question 3 (18 marks) A bit stream is modulated by using QPSK and transmitted over an AWGN channel of bandwidth 200 kHz

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Question 3 18 Marks A Bit Stream Is Modulated By Using Qpsk And Transmitted Over An Awgn Channel Of Bandwidth 200 Khz 1 (47.34 KiB) Viewed 84 times

Question 3 (18 marks) A bit stream is modulated by using QPSK and transmitted over an AWGN channel of bandwidth 200 kHz with 90% in-band power. At the receiver side, the two-sided noise power spectral density is found to be 106 W/Hz, and the BER is found to be 10-9 with the optimal receiver adopted. 1. Determine the symbol rate, SER and received signal power. (7 marks) 2. If the channel frequency range is allocated to [0, 200 kHz), can the modulated signal pass through the channel with 95% in-band power? State your reason. (3 marks) 3. If your answer to Q3.2 is yes, determine the maximum bit rate that can be supported by the channel. Otherwise, provide one modulation scheme that can achieve it, with justifications. In both cases, determine whether a BER of 5x10 can be achieved when the received signal power is increased by 4 dB. (8 marks)