Measurements of wideband multi-element transmit-receive diversity channels in the UMTS-band

Three element transmit (Tx) (at base station BS) by four element receive (Rx) (at portable unit PU) antenna systems have been investigated at 2 GHz. Simultaneous sounding of all 3Tx by 4Rx=12 parallel links has been performed using a Doppler offset technique. This allows for investigations of simultaneous Tx-Rx diversity effectiveness as well as support for disclosing the degree of parallelism (independent channels). The measurement main-lobe bandwidth is 8 MHz. This allowed a maximum range of approx. 2.5 km with 0.4 W Tx-power and 23 dBi total antenna gain. This paper focuses on the fundamental power balance between links, which is a basic limiting factor for both diversity action and parallelism.