Patent ID: 6542519
Filing Date: 2003-04-01
Classification: H01Q,H04B

Abstract:
An apparatus for intentional sidelobe creation utilized in a TDMA system transmitting signals for obtaining a diversity function used in a cellular mobile telephone system, comprising:a first transmitter transmitting a first signal carrying information for a current mobile station using a current times slot, said signal carrying information being transmitted by an antenna beam covering the position of current mobile station; a second transmitter transmitting a second signal for obtaining signal power for a second mobile station to receive information in a next time slot, said second transmitted signal having low cross correlation relative to said first transmitted signal and transmitted at a lower power level and intended, together with said first signal, to create a substantial detectable power level in a direction towards, the second mobile station for its diversity function to operate in preparing for the reception of information in the next time slot; a first switch fed by said first transmitter, for connecting the first signal to one branch out of a first path of K branches, the selected one branch being the one having a main beam in the direction towards the first mobile station; a second switch fed by said second transmitter at a reduced power level, for connecting the second signal to one out of a second path of K branches for obtaining an intentional sidelobe in the direction to the second mobile station; and a first path of combiner combining the first K branches and second path of K branches to output a third path of K branches to be fed to a Butler matrix, said Butler matrix feeding corresponding antenna elements creating a main beam towards the current mobile station receiving the current time slot and an intentional sidelobe covering the second mobile station to receive the following time slot, the cross correlation being low between the first signal producing the main beam and the second signal for the intentional sidelobe creation.