| 摘要 |
<p>The invention relates to a base transceiver station and a method for allocating a code in connection with soft handover in a CDMA system in downlink transmissions from the base transceiver station to a mobile station, in which method codes are allocated in the base transceiver station according to a specific code tree, wherein a specific first spreading factor corresponds to each code (C2, 1) and from a code that has a specific spreading factor, it is possible to derive two codes (C4, 1, C4, 2) that have a higher second spreading factor. The method comprises allowing the base transceiver station to use said first spreading factor (SF=2) in code allocation in all downlink transmissions; allowing the base transceiver station to use both codes (C4, 1, C4, 2) that have said second spreading factor (SF=4) in code allocation in downlink transmissions when the receiving mobile station is in connection with only one base transceiver station simultaneously; limiting the use of said second spreading factor (SF=4) in code allocation in downlink transmissions when the receiving mobile station is in connection with at least two base transceiver stations simultaneously so as to allow the base transceiver station to use only one (C4, 1 or C4, 2) of said two codes (C4, 1, C4, 2) that have said second spreading factor (SF=4).</p> |
