Apparatus and method for synchronization of uplink synchronous transmission scheme in a CDMA communication system

A method for synchronizing a scrambling code in a UE of a CDMA communication system including a UTRAN and a plurality of UEs, using orthogonal codes for identifying the UEs and a single uplink scrambling code for the UEs to identify the UTRAN and employing an uplink synchronous transmission scheme (USTS) where the UEs synchronize frames of uplink physical channels using the single scrambling code, wherein the UEs receive a signal providing system timing provided from the UTRAN and transmit a random access channel (RACH) signal based on the system timing, comprising the steps of:

• determining a transmission time upon receipt of a transmission time adjustment value for slot synchronization from the UTRAN in response to the transmitted RACH signal;
• creating a scrambling code at the system timing;
• creating a data frame at the determined transmission time;
• and
• scrambling, at the determined transmission time, the data frame with the scrambling code generated at a time being different from a transmission time of the frame data with a scrambling code offset calculated from the transmission time adjustment value.

An apparatus for synchronizing a scrambling code in a UE of a CDMA communication system including a UTRAN and a plurality of UEs, using orthogonal codes for identifying the UEs and a single uplink scrambling code for the UEs to identify the UTRAN, and employing an uplink synchronous transmission scheme (USTS) where the UEs synchronize frames of uplink physical channels using the single scrambling code, wherein the UEs receive a signal providing system timing provided from the UTRAN and transmit a random access channel (RACH) signal based on the system timing, the apparatus comprising:

• a controller for determining a transmission time upon receipt of a transmission time adjustment value for slot synchronization from the UTRAN in response to the transmitted RACH signal;
• a scrambling code generator for creating a scrambling code at the system timing;
• a frame generator for creating a data frame at the determined transmission time;
• and
• a scrambler for scrambling, at the transmission time determined by the controller, the data frame with the scrambling code generated at a time being different from a transmission time of the frame data with a scrambling code offset calculated from the transmission time adjustment value at the system time.

A method for data transmission in a communication system, the method comprising:

• receiving, at a Network, a Random Access Channel (RACH) transmitted from a User Equipment (UE);
• calculating a transmission time adjustment value for the UE;
• transmitting the transmission time adjustment to the UE;
• receiving, at the UE, the transmission time adjustment value;
• calculating a starting timing of an uplink frame;
• generating an orthogonal code for spreading the uplink frame at the starting timing of the uplink frame;
• generating a scrambling code for scrambling code for scrambling the uplink frame at a predetermined timing;
• and
• transmitting the uplink frame scrambled and spread by the scrambling code and the orthogonal code with reference to the starting timing of the uplink frame.