Mobile station loop-back signal processing

A method of transmit signal pre-compensation at a wireless communication network, the method comprising:

• retaining transmit information associated with a combined transmit signal transmitted from the network to one or more mobile stations, wherein the combined transmit signal is formed from one or more individual information signals intended for different ones of the mobile stations, and wherein the transmit information associated with the combined transmit signal comprises the individual information signals used to form the combined transmit signal;
• receiving loop-back signals from the mobile stations, wherein the loop-back signals comprise mobile station receiver output values;
• determining one or more estimated transmit channel characteristics based on comparing the retained transmit information with loop-back information obtained from the loop-back signals;
• generating cross-correlation compensation values based on correlating the mobile station receiver output values obtained from the loop-back signals with corresponding information symbols in the retained individual information signals;
• and
• performing pre-compensation processing for the combined transmit signal based on the estimated transmit channel characteristics and compensating the individual information signals used to form the combined transmit signal with the cross correlation compensation values.

A method of providing loop-back information to a wireless communication network, the method comprising:

• receiving a composite spread spectrum signal transmitted by the network at a mobile station, the composite spread spectrum signal including a plurality of differently spread individual information signals intended for different ones of a plurality of mobile stations;
• processing the composite signal to recover mobile-specific signal samples by:
• despreading the composite spread spectrum signal to recover the individual information signal intended for the mobile station;
• and
• demodulating soft symbol values from the individual information signal as the mobile specific signal samples;
• and
• transmitting at least some of the mobile-specific signal samples back to the network as a loop-back signal.

A method of pre-compensating a transmit signal transmitted to one or more mobile stations by a wireless communication network, the method comprising:

• receiving a plurality of loop-back signals from the plurality of mobile stations comprising loop-back samples of the transmit signal as received by the mobile stations;
• retaining samples of individual information signals intended for different ones of the plurality of mobile stations, including a mobile station from which a loop-back signal is received, wherein one or more of the individual information signals are included in the transmit signal;
• removing uplink channel effects from the plurality of loop-back signals;
• generating estimated output samples that would be obtained at the receivers of the plurality of mobile stations based on processing the loop-back signals at the network using one or more mobile station receiver models;
• determining interference between the plurality of individual information signals based on cross-correlating the retained samples for the individual information signals with the estimated output samples;
• and
• compensating the individual information signals to reduce the determined interference.