An antenna selection diversity reception system

Claim 1

An antenna selection diversity receiver system for a time division multiplex receive signal comprising ; - a plurality of antennas (1, 2), - a selection switch (3) for selecting one of said antennas, - a receiver/demodulator (4) coupled with the selected antenna through said selection switch for providing a demodulated receive signal and a receive level, - a frame synchronization circuit (5) coupled with a first output of said receiver/demodulator (4) for effecting frame synchronization of the time division multiplex signal, - an antenna selection circuit (7) coupled with a second output of said receiver/demodulator (4) for receiving said receive level, and coupled with said selection switch (3) for controlling said selection switch (3) ; - said antenna selection circuit (7) comprising ; - a timing circuit (7-1) coupled with said frame synchronization circuit (5) for finding the beginning of an assigned time slot, - first storage means (7-5, 7-6) for storing the receive level of each antenna just before said assigned time slot, and - a switch control circuit (7-2) coupled with said timing circuit, CHARACTERIZED IN THAT said antenna selection circuit (7) further comprises ; - slope means (7-7) for providing a slope of said receive level of each antenna, - second storage means (7-8, 7-9) for storing the output of said slope means, - prediction means (7-10) for predicting a receive signal quality of each antenna in the assigned time slot according to said receive level and said slope by using the output of said first storage means and said second storage means, and - the switch control circuit (7-2) also coupled with said prediction means for switching said selection switch just before the beginning of said assigned time slot for every assigned slots so that the antenna providing the best predicted receive signal quality in the assigned time slot is selected.