Low-if pre-preamble antenna diversity receiver

An antenna diversity receiver, comprising a low intermediate frequency receiving groove and diversity selecting way and a switch device, is used for receiving the groove and intermediate frequency channel coupling of the antenna, and a selecting way and different an overhead connecting each channel. Diversity the controller is for takes with different antenna from the signal quality of a comparing the lower selecting way, and receiving groove switching device, so that the number of by good antenna. During receiving need to the signal preamble arranged on the carrier end of the signal plug, so that the number of with a longer time for obtaining better signal quality measurement, and method of better to the time middle effect. The channel with the channels with capable of the crossed coupling multi-phase filter, in order to the filter be two independent low-pass filter uses the lower selecting way.