How do I design a frequency plan for a multi-band multi-standard radio covering LTE and 5G NR?

Designing a frequency plan for a multi-band, multi-standard radio covering LTE and 5G NR requires selecting the local oscillator (LO) frequencies and IF frequencies for each band to ensure that all bands can be received and transmitted without any spurious signals falling within the desired signal bandwidth. The design involves: listing all required bands (LTE bands: B1 (2100 MHz), B3 (1800 MHz), B7 (2600 MHz), B20 (800 MHz), etc.; 5G NR bands: n77 (3300-4200 MHz), n78 (3300-3800 MHz), n79 (4400-5000 MHz), n257/n258/n260/n261 (mmW bands); each band has defined uplink and downlink frequency ranges), selecting the receiver architecture (direct conversion (zero-IF): the LO frequency equals the center frequency of the desired band; simplest architecture but requires DC offset and I/Q imbalance calibration. Low-IF: LO offset by a small IF (1-10 MHz) to avoid DC issues. Superheterodyne: one or two IF stages with fixed IF frequency; provides the best selectivity and spurious performance), computing all spurious frequencies for each LO setting (for each combination of RF and LO frequencies: calculate the mixing products at m x f_RF ± n x f_LO for m, n = 0, 1, 2, 3, ...; identify any spurious products that fall within any of the desired receive or transmit bands), optimizing the LO frequencies to minimize in-band spurious products (this is an iterative process, often aided by software tools that evaluate thousands of LO/IF combinations and rank them by the severity of spurious products; the goal is to find LO/IF combinations where no significant spurious product falls within any receive band), and verifying the frequency plan with system simulation (simulate the complete receiver chain with realistic mixer nonlinearity to confirm that all spurious products are below the required level, typically -70 to -90 dBc).