| 摘要 |
PURPOSE: A flexible modulator uses both BPSK(binary phase shift keying) method and QPSK(quadrate phase shift keying) method in a wide band CDMA system. CONSTITUTION: A flexible modulator includes a first link selector, a hadamard spreading part, I/Q substitution part(770), and PN code spreading part, The first link selector receives a reverse channel signal for a spread modulation or I(In phase) signal and Q(quadrate) signal for a spread modulation of a forward channel, and selects a modulation method. The hadamard code spreading part receives I signal and Q signal from the first link selector, and performs a hadamard code spread modulation. I/Q substitution part exchanges paths of I signal and Q signal which are hadamard spread modulated to each other if an exchange is needed about a forward signal. The PN code spreading part performs PN code spreading modulation about the exchanged I signal and Q signal. Thereby, minimum gates are used, a reliability of ASIC is enhanced when the modulator is implemented by using ASIC, and a power consumption is minimized.
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