CDMA MODULATION AND DEMODULATION METHOD SIMPLIFYING SYNCHRONIZATION PROCESS

• Main Author: RYU, SEUNG MUN
• Format: Patent
• Language: English; Korean
• Published: 18.07.2002
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

PURPOSE: A CDMA modulation and demodulation method simplifying a synchronization process is provided to simplify a receiving circuit by easily solving problems related to synchronization, thereby constructing an economic CDMA system. CONSTITUTION: Data to be transmitted are divided by frame length corresponding to positive number times of an orthogonal code period to maintain the characteristics of a CDMA signal. A synchronizing signal having different pulse width from the CDMA signal is inserted between frames. The pulse width of the final synchronizing signal is set differently from the front synchronizing signal to sense the end of the inserted synchronizing signal. Synchronization of the CDMA signal transmitted to each frame is taken by using the inserted synchronizing signal, and then correlation is taken by using the CDMA signal within one frame right after the synchronizing signal for confirming synchronization. The confirmed synchronization time is used as basic time for one frame length by adjusting fine time due to time difference in a transceiver. In case that each frame fails in detecting the synchronizing signal, the synchronizing signal of the former frame is used.