asurements or similar. 10 dB blocker margin. Receiver blocking occurs when the signal that is intended to be received is "blocked" because unintended signals (typically from nearby sources) radiate in or near the passband of the RF receiver and reduce the sensitivity to the intended signal. Specifically, in use-cases where IBW and OBW are not the same, analog (baseband and RF) filters do not match exactly with the signals intended to be received and blocker signals should be taken into consideration. Note that blocker margin is a key design consideration that impacts the analog (filter) and ADC performance. Consider a 2G (GSM) example where the required receiver sensitivity is -102 dBm with an adjacent (3 MHz carrier offset) specified at up to -23 dBm. The approximately 80 dB difference in signal strength needs to be overcome by a combination of (RF but mainly baseband) analog filtering combined with blocker margin in the ADC specification. 134 Open Radio Access Network (O-RAN) Systems Architecture and Design -3dB processing gain from oversampling (245.76 MHz over 122.88 MHz). The Processing Gain is defined as the gain had from oversampling the desired signal with a rate above the Nyquist frequency. In aggregate: 25 + 12 + 4 + 2 + 10 + 10-3=60 dB Note, this does not include any additional safety margin. The analysis is shown graphi- cally in Fig. 3-21. Digital to Analog Converter (DAC) performance is assessed in a similar fashion to ADC performance: Sample rate Fsample is defined from the signal bandwidth which is 100 MHz in the RF domain or 50 MHz for I and Q each. Given 3GPP sample rates in multiples of 30.72MSPS, we assume 122.88MSPS as a minimum sample rate above Nyquist criterium or 245MSPS with 2x oversampling to simplify aliasing filter implementation or 491.76MSPS if we add enough bandwidth for DPD correction. SNR requirements are defined as: Assume 30 dB required for 256QAM support as derived from the 3GPP specified 3.5% Error Vector Magnitude (EVM) Add SNR margin-the EVM shall be dominated by the PA, af