Question

30 Q1 A LTE system employs orthogonal frequency division multiple access (OFDMA) transmission for downlink transmission, in which users are allocated a specific number of subcarriers for a predetermined amount of time, referred to as physical resource blocks (PRBs) in the LTE specifications. A PRB is defined as consisting of 12 consecutive subcarriers for one slot in duration. Given that the subcarrier spacing is 15 KHz, and transmission bandwidth over a 2.7GHz carrier is 20 MHz, and 6 OFDM symbols (plus cyclic prefix) form a slot of 0.5 ms. Assume that the channel power delay profile at 2.7 GHz is: exp(-t/th), where th -5 us:

Determine the RMS(root mean square) delay spread.

Answer 1

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