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Wireless Access Systems: Exercise 3 – UWB Transceiver. Goals. We will simulate a complete UWB transceiver: Task 1 – UWB BPPM Transmitter. Task 2 – UWB Energy Receiver and path loss. Combination - UWB transceiver with FCC power constraints. Task 1 – BPPM.
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Goals • We will simulate a complete UWB transceiver: • Task 1 – UWB BPPM Transmitter. • Task 2 – UWB Energy Receiver and path loss. • Combination - UWB transceiver with FCC power constraints. Communication Technology Laboratory Wireless Communication Group
Task 1 – BPPM • The Binary Pulse Position Modulation Communication Technology Laboratory Wireless Communication Group
Task 1 – BPPM • Generate a sequence of BPP modulated bits/symbols. • Some questions to answer... • How many full periods of a cosine represent a UWB pulse? • How many sample points represent one pulse? • Compute the PSD of the signal. Communication Technology Laboratory Wireless Communication Group
Task 1 – PSD of UWB pulse • Analyze the power spectral density (PSD) of the UWB pulses. • First, estimate the continuous-time spectrum of the signal: Communication Technology Laboratory Wireless Communication Group
Task 1 – PSD of UWB pulse • Energy: • Power spectral density: • Plot the PSD of the UW pulse • Label the x-axis appropriately Communication Technology Laboratory Wireless Communication Group
Task 2 – Path Loss • Having the transmit signal, introduce the effect of the channel. • We will use the AWGN channel with path loss (= line of sight channel). • The path loss effect on the transmit signal power is the result of the distance between thesource and the transmitter. : the path loss effect : The PSD of the noise is : The power of one BPPM bit Communication Technology Laboratory Wireless Communication Group
Task 2 – Channel and Noise • In other words, • Add real noise: • Note and Communication Technology Laboratory Wireless Communication Group
Task 2 – Energy Detector • Energy Detector • Play with the integration duration (i.e., summation), compute BER and find until where you need to sum to get the best BER result. Communication Technology Laboratory Wireless Communication Group
Combination Task – UWB Transceiver • Transmit 400 bits every 1 msec. (Low duty cycle) • We must compute the energy in 1 MHz bins. • Filter the transmit signal with a 1 MHz wide filter around f0. • Compute the FFT of the transmit signal. Use 10 μsec of signal. • Construct the filter in the frequency domain. • Perform the filtering and transform again in the time domain. Communication Technology Laboratory Wireless Communication Group
Combination Task – UWB Transceiver • Scan the frequencies from 3.5 to 4.5 GHz. • Compute the square of the filtered signal, and then the average over 1 ms. • Scale the power of the transmit signal according to the FCC average power limit of -41.3 dBm/MHz. • Perform the rest of the simulation as in Task 2. Communication Technology Laboratory Wireless Communication Group