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Navegación:  Cartography and Planning > Planning Process > 3G Mobile Communications > 3G Parameters HSDPA/HSUPA


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The calculation parameters for third generation mobile HSDPA and HSUPA are:


Power Increasing (dB). In radio planning of cellular networks it is been used averaged magnitudes over fast multipath variations. Thus, the received signal power (sensitivity) and the attenuation of propagation (basic loss) are average values.

Similarly, the transmitted power is an average over the rapid changes imposed by the power control, which tries to compensate for multipath fading. In a classical system (without fast power control), the received power S can be obtained from the transmitted power Pt and the propagation basic losses Lb (average values over rapid variations) like:

S = Pt-Lb+Gt+Gr-L0 (1)

where Gt and Gr are the antennas gains, and L0 is a term of additional losses (cables, coupling elements, user's body).

In HSDPA/HSUPA systems, the existence of a fast power control makes the expression (1) ceases to be valid. To satisfy equality in the expression it is necessary to subtract a term called transmit power rise, I, so:

S = Pt-I-Lb+Gt+Gr-L0 (2)

Physically, the term I means that it is required a higher average transmission power for the same average power at reception, compared to a system without fast power control. The extra power is not used for increasing the average power received, but for the power received to have less variation. This term usually take values between 0 and 3 dB, depending on propagation conditions (mainly on the speed of user movement).

SHO gain by shadow fading. When evaluating the cell coverage can be assumed that users located on the cell's edge are in a position to handover continuously (soft handover) with one or more neighboring cells, so they are received simultaneously at several bases. As a result, there is improvement due to reception diversity. One effect of this diversity is that the margin necessary to take into account the shadow fading is less than the one that would exist with a single base. There is thus a gain term, which must be subtracted from the log-normal margin calculated as usual. If in this margin calculation has been taken into account this effect is not necessary to apply any corrections.