1/2fs direct RF under sampling reception in different RX channels

We proposed an RF under sampling technique that allows the use of half the sampling frequency than is conventionally required for a single channel system. In this paper, a fs design methodology for multi-channel system is described and the application of this technique to the reception of signals in different channels is demonstrated. For the conventional technique, fs is constant even if the channel of reception changes, but in our proposed technique, fs is changed according to the channel´s location in the system bandwidth. To validate the proposed fs design methodology, measurement of a front-end using the conventional and the proposed techniques was performed. The measured SNR for the proposed technique for channel one, two and three were 30.4 dB, 28.0 dB and 27.2 dB respective. Using QPSK modulation the EVM was measured to be −23.5 dB, −23.4 dB and −23.6 dB for Channel one, two and three respectively.