Apparatus and method for dynamically assigning orthogonal codes in a radio communication system

A method performed within a radio base station for dynamically assigning spreading codes to different information signals communicated between the radio base station and a user terminal in a cellular radio communication system in which a number of codes are allocated for dedicated transport channels (DCHs) and a number of codes are allocated for high speed downlink shared channels (HS-DSCHs), and a radio network controller allocates codes for HS-DSCH physical channels (HS-PDSCH codes) to the radio base station, said method comprising the steps of:

• monitoring code use within the radio base station to determine whether there are unused codes that are not being utilized as either DCH codes or HS-PDSCH codes;
• upon determining that there is at least one unused code that was not allocated by the radio network controller, allocating additional HS-PDSCH codes from unused codes that were not allocated by the radio network controller, in addition to the HS-PDSCH codes that were allocated by the radio network controller, without communicating with the radio network controller;
• and
• maintaining the HS-PDSCH codes allocated by the radio network controller as a minimum number of HS-PDSCH codes.

A system for dynamically assigning spreading codes to different information signals communicated between a radio base station and a user terminal in a cellular radio communication network in which a number of codes are allocated for dedicated transport channels (DCHs) and a number of codes are allocated for high speed downlink shared channels (HS-DSCHs), and a radio network controller allocates codes for HS-DSCH physical channels (HS-PDSCH codes) to the radio base station, said system comprising:

• an HS-PDSCH code allocation processor within the radio network controller configured to allocate a minimum number of HS-PDSCH codes to the radio base station;
• and
• a discretionary code allocation processor within the radio base station configured to:
• allocate and de-allocate additional HS-PDSCH codes from unused codes that were not allocated by the radio network controller, in addition to the HS-PDSCH codes that were allocated by the radio network controller, without communicating with the radio network controller;
• and
• maintain the HS-PDSCH codes allocated by the radio network controller as the minimum number of HS-PDSCH codes.