the PLL are the phase- frequency detector, loop filter, voltage-controlled oscillator, and counters, such as a feedback counter, prescale counter, and postscale counters. Digital processing Analog front-end RF analog processing Modem IF filter Diplexer VCO + mixer Figure 5.25 High-level system architecture of point-to-point mmWave radio [ [23]. New Radio Access RF and Transceiver Design Considerations 721 A quadrature I/Q ADC is required in order to sample the IF (or baseband in case of zero-IF receiver) I/Q analog signals down-converted from the mmWave receiver. Typical channel bandwidths range from 250/500 MHz for traditional backhaul systems to 1 GHz or higher for the 5G systems, thus the sample rates would be in the excess of 500 MHz depending on the required over-sample ratio for a given modem implementation. The required resolution or ENOB is primarily a function of modulation scheme which ranges from 4 bits for QPSK to 5 bits for 16QAM, and 6 bits for 64QAM. There is a need for additional dynamic range to support OFDM waveform compared to single-carrier waveform due to power summation over multiple subcarriers (crest factor). This requires an additional 5-6 dB dynamic range for OFDM waveform compared to single-carrier waveform for a given modulation index. In order to determine the dynamic range of the ADC for a given modulation scheme and receiver, the noise floor of ADC and the receiver noise must be carefully modeled. The noise floor of the ADC is defined by the power level of the (quantization) noise produced by the ADC itself when referred back to the receiver input, that is, the actual ADC noise power divided by the gain of the front-end. Conventionally, this is set to a level approxi- mately 10 dB below the total effective noise power at the input to the receiver SO that the effect of the ADC is to increase the front-end NF by 0.5 dB. The receiver noise power is just thermal noise power (KTB) raised by the receiver NF in dB [23]. In addition to the receiver noise, a margin must be added for the mini