Directional UMTS up-down-link channel balance with cross polarised information

antprop Adaptive BS arrays are considered as capacity enhancing measures for UMTS. While it is in principle straightforward to achieve instant channel knowledge on the uplink (UL) - it is more difficult on the downlink (DL). For this reason CPK has developed a sounding system providing 16 (8UL + 8DL) fully simultaneous channels for use with 8-element BS arrays for direction information - and a further switched 16 channels for the orthogonal polarisation. Totalling 32 parallel sounded channels. The sounding bandwidth is 12 MHz. [Kovacs, Eggers et al, 2002]. Measurements have been performed in suburban and urban Aalborg during 2001 and 2002.CPK Annual Report 2001 - Figure 4.5.7 (a-f Directional pattern resulting from 8 element UMTS BS array for location 3 (a,c,e) and 8 (b,d,f). a and b show PDP's, c and d I PAS, and e and f show the PAS distribution over time). Figures 4.5.7a and 4.5.7b show the Power Delay Profile (PDP) averaged over the elements of the array and measured respectively at location 3 and 8 processing [Djama, Kovacs et al, 2002]. They reveal that the power is concentrated in several delay clusters (three for location 3 and two for location 8) with almost always one "widely" dominating. At each delay cluster, a corresponding specific DOA is seen, as shown in the Instantaneous Power Azimuth Spread (I PAS) of Figures 4.5.7c and 4.5.7.d, justifying the thesis that each delay cluster corresponds to an individual propagation path. The azimuth 0± corresponds to the azimuth towards the MS. Figures 4.5.7e and 4.5.7f indicate that during the 30 seconds of measurement at each location, the "individual propagation paths" remain the same, explained by the fact that the area of motion was relatively small. The azimuth spread analysis reveals that for most of the measured mobile location the incident power is highly concentrated around the direction MS-BS even though the measurements have been obtained in a no-LOS situation. This project is performed in cooperation with ArrayComm Inc. and Allgon Systems AB. (Patrick Eggers, Istvan Kovacs, Kim Olesen, Kamel Djama, J. Bach Andersen)