| 20110092171 | SIGNAL COMBINER - At present a number of frequency bands in the region of 450, 950, 900, 1700, 1800, 1900 and 2100 MHz are utilised for cellular and mobile communications, additional bands are under consideration for future expansion of such wireless communication systems. Recently, placing UMTS signals into existing GSM spectrum has received increasing levels of interest. The present invention is directed to systems and methods of combining GSM and UTMS signals in a shared methodology that offers good isolation. A number of different combiner structures are disclosed, the various combiner types each utilise differing transmitter ports topologies to effect the placement of UTMS signals within the existing GSM spectrum and vice versa. | 04-21-2011 |
