Method and apparatus in a CDMA communication system

A method for a soft handoff operation in a CDMA communication system, comprising:

• measuring a reception downlink time offset experienced at a mobile station between a first downlink transmission received from a first base station and a second downlink transmission from a second base station;
• communicating said measured reception downlink time offset from said mobile station to at least one of said first and second base stations;
• receiving data frames from said first base station at said mobile station in accordance with a first downlink data frame time offset, wherein said first downlink data frame time offset is measured from a channel frame timing associated with the first base station;
• receiving a second downlink data frame time offset at said mobile station for said soft handoff operation, wherein said second downlink data frame time offset is determined based on said measured reception downlink time offset, and wherein said second downlink data fame time offset is measured from a channel frame timing associated with the second base station, and wherein said first and second downlink data frame time offsets are in increments of a predetermined number of chips;
• and
• receiving data frames from said second base station at said mobile station in accordance with said second downlink data frame time offset, wherein data frames received from said first and second base stations carry the same data for said soft handoff operation.

An apparatus for a soft handoff operation in a CDMA communication system, comprising:

• a transmitter and a receiver, wherein said receiver includes a timing block, a de-spreader, a demodulator and a decoder, configured for performing a set of operations including:
• measuring a reception downlink time offset experienced at said receiver between a first downlink transmission received from a first base station and a second downlink transmission from a second base station;
• communicating said measured reception downlink time offset from said transmitter to at least one of said first and second base stations;
• receiving data frames from said first base station at said receiver in accordance with a first downlink data frame time offset, wherein said first downlink data frame time offset is measured from a channel frame timing associated with the first base station;
• receiving a second downlink data frame time offset at said receiver for said soft handoff operation, wherein said second downlink data frame time offset is determined based on said measured reception downlink time offset, and wherein said second downlink data frame time offset is measured from a channel frame timing associated with the second base station, and wherein said first and second downlink data frame time offsets are in increments of a predetermined number of chips;
• and
• receiving data frames from said second base station at said mobile station in accordance with said second downlink data frame time offset, wherein data frames transmitted from said first and second base stations carry the same data for said soft handoff operation.

A method for a soft handoff operation in a CDMA communication system, comprising:

• transmitting data frames from a first base station to a mobile station in accordance with a first downlink data frame time offset, wherein said first downlink data frame time offset is measured from a channel frame timing associated with the first base station;
• receiving a measured reception downlink time offset from said mobile station at one of said first and second base stations, wherein said measured reception downlink time offset is the reception time offset experienced at said mobile station between a first downlink transmission from said first base station and a second downlink transmission from a second base station;
• determining a second downlink time offset based on said measured reception downlink time offset, wherein said second downlink data frame time offset is measured from a channel frame timing associated with the second base station wherein said first and second downlink data frame time offsets are in increments of a predetermined number of chips;
• communicating said second downlink data frame time offset to said mobile station for said soft handoff operation;
• and
• transmitting data frames from said second base station to said mobile station in accordance with said second downlink data fame time offset, wherein data frames transmitted from said first and second base station carry the same data for said soft handoff operation.

An apparatus for a soft handoff operation in a CDMA communication system, comprising:

• a transmitter, a receiver and associated control apparatus configured for performing a set of operations for said handoff operation, wherein said set of operations includes:
• transmitting data frames from a first base station to a mobile station in accordance with a first downlink data frame time offset, wherein said first downlink data fine time offset is measured from a channel frame timing associated with the first base station;
• receiving a measured reception downlink time offset from said mobile station at one of said first and second base stations, wherein said measured reception downlink time offset is the reception time offset experienced at said mobile station between a first downlink transmission from said first base station and a second downlink transmission from a second base station;
• determining a second downlink time offset based on said measured reception downlink time offset, wherein said second downlink data frame time offset is measured from a channel frame timing associated with the second base station, wherein said first and second downlink data frame time offsets are in increments of a predetermined number of chips;
• communicating said second downlink data frame time offset to said mobile station for said soft handoff operation;
• and
• transmitting data fines from said second base station to said mobile station in accordance with said second downlink data frame time offset, wherein data frames transmitted from said first and second base station carry the same data for said soft handoff operation.