Method and arrangements for load balancing of power amplifiers

A method for transmitting radio communication signals from a transmit unit with at least two antennas comprising the following steps;

• transmitting signals relating a High Speed Downlink Shared Channel, HS-DSCH, in a HSDPA system using a first subset of channelization codes from said first antenna;
• transmitting pilot signals on a first type of pilot channel from said first antenna for use as a reference for said HS-DSCH using said first subset of channelization codes;
• transmitting signals relating the HS-DSCH using a second subset of channelization codes from said second antenna by using single antenna transmission;
• transmitting pilot signals on only a second type of pilot channel different from said first type of pilot channel from said second antenna for use as a reference for said HS-DSCH using said second subset of channelization codes, wherein the first subset of channelization codes together with the second subset of channelization codes covers the totality of the channelization codes of the HS-DSCH, and wherein the first and second type of pilot channels are covering substantially the same area.

A control unit for controlling a transmit unit having at least two antennas for transmitting signals relating to a plurality of radio channels, wherein said control unit comprises means for controlling said transmit unit to:

• transmit signals relating to a High Speed Downlink Shared Channel, HSDSCH, in a HSDPA system, using a first subset of channelization codes from said first antenna;
• transmit pilot signals on a first type of pilot channel from said first antenna for use as a reference for said HS-DSCH using said first subset of channelization codes;
• transmit signals relating to said HS-DSCH using a second subset of channelization codes from said second antenna by using single antenna transmission;
• transmit pilot signals on only a second type of pilot channel, different from said first type of pilot channel, from said second antenna for use as a reference for said HS-DSCH using said second subset of channelization codes, wherein the first subset of channelization codes together with the second subset of channelization codes covers the totality of the channelization codes of the HSDSCH, and wherein the first and second type of pilot channels are substantially covering the same area.