le 15.10 Nominal SINR requirements for the example based on downlink having two transmit antennas Downlink PDSCH Uplink PUSCH SINR SINR requirement at requirement at 90% 100% PRB Layer PRB utilization, 2Rx utilization, 2Tx/2Rx LTE1800 20 MHz -7 dB -3 dB LTE800 0MHz -7 dB -3 dB Low UE mobility (Doppler frequency = 3 Hz). no other cell interference, RSRP can be used as the mobility trigger since SNR can be derived with sufficient accuracy if thermal noise power in uplink and downlink is known. For downlink the thermal noise level is about-125 dBm per subcarrier, depending somewhat on the UE noise figure (which in turn depends on the operating band). To satisfy SNR = -3 dB the RSRP should be higher than 128 dBm. The reference signal transmit power for one subcarrier is 15 dBm. This brings the maximum downlink path loss 14 to 125 + 15 = 140 dB. Uplink SNR needs to be checked to ensure robust control channel operation. At 23 dBm transmit power and 1 PRB bandwidth the received power is 23-140 = -117 dBm which 2 dB above the eNodeB thermal noise floor (SNR = 2 dB). Thus for PUCCH the SNR target of -3 dB is still satisfied in the absence of uplink interference. For the uplink data channel, power control will impact throughput at high RSRP. For low RSRP, it can be assumed that UE is already using its full transmission power of 23 dBm for any practical uplink power control scheme. For 90 PRBs bandwidth, the thermal noise power is roughly -100 dBm if MHA is used or the feeder loss is not excessive. The maximum path loss to satisfy PUSCH SNR = -7 dB under thermal noise is around 23 + 100 + 7 = 130 dB. This corresponds to RSRP of 15 - 130 = -115 dBm. Since the RSRP requirement for downlink throughput was determined to be -128 dBm, it can be seen that it is the uplink throughput requirement that limits coverage. The path loss values calculated above can live a few decibels in either direction depending on various system parameters; the main purpose here is simply to get an idea on the uplink- downlink power imbalance. The resu