Determining transmit signal powers of channels in a CDMA communications system

A method of determining gains of signals of each of a plurality of data channels relative to a signal of a pilot channel, said signals being spread using orthogonal codes, for combining said signals for transmission from a mobile station to a base station of a CDMA (code division multiple access) communications system with an initial power sufficient for recovery of the signals of the data channels at the base station each with a respective data rate and a respective maximum error rate, comprising the steps of:

• (a) for each of the data channels, determining a signal bit energy to noise ratio in accordance with the maximum error rate of the data channel;
• (b) for each of the data channels, determining a respective channel energy to noise ratio from the determined signal bit energy to noise ratio and a signal processing gain for the data channel;
• (c) for each of the data channels, determining a respective pilot channel energy to noise ratio sufficient for recovery of the signal of the data channel by the base station;
• (d) selecting a maximum one of the respective required pilot channel energy to noise ratios as an energy to noise ratio for transmission of the pilot channel;
• and
• (e) determining relative gains for combining the signals of the data channels with the signal of the pilot channel from the respective data channel energy to noise ratio determined in step (b) and the pilot channel energy to noise ratio selected in step (d).