ORTHOGONAL COMPLEX SPREADING METHOD FOR MULTIPLEX CHANNEL

• Main Authors: SHIM JAE RYONG, KIM JUNG IM, BANG SEUNG CHANG, KIM TAE JOONG, HAN KI CHUL
• Format: Patent
• Language: English
• Published: 09.07.1999
• Edition: 6
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; MULTIPLEX COMMUNICATION; TRANSMISSION

PROBLEM TO BE SOLVED: To provide an orthogonal complex spreading method and its system for a multiplex channel by which a problem of unbalanced power between in-phase channels and orthogonal phase channels is solved, and which has an advantage over complex spreading systems proposed by CDMA-ONE in the U.S. and by W-CDMA in Japan and Europe, from the standpoint of power efficiency. SOLUTION: 'Orthogonal complex spread miodulation' is called an OCQPSK (orthogonal complex QPSK). Data for a multiplex channel and subject to gain and orthogonal Hadamard sequence for each channel, two channel data multiplied with the gain and the orthogonal Hadamard sequence are summed in a complex form, a complex multiplier applies complex multiplication to the value summed in the complex form and the outer orthogonal Hadamard sequence in a complex form, and provides outputs of in-phase information and orthogonal phase information. The in- phase information outputted from lots of blocks is summed to the in-phase information and the orthogonal phase information is summed to the orthogonal phase information, and the result is spread by using a spread code in the orthogonal complex spread method for the multiplex channel.