A test system for testing a wireless electronic device is provided. The test system may include a test host and a tester. The test host may instruct the electronic device under test (DUT) to transmit radio-frequency test signals in a selected resource block of a desired channel identified by a channel number in the Long Term Evolution frequency band. The tester may measure harmonic output power levels of the radio-frequency test signals transmitted by the DUT at harmonic frequencies of the selected resource block. The test host may compare the measured harmonic output power levels to threshold power levels to characterize the radio-frequency performance of wireless circuitry in the DUT. The test system may test the radio-frequency performance of the DUT for radio-frequency test signals transmitted by the DUT in some or all resource blocks in the desired Long Term Evolution band.