MSK MODULATOR, DIGITAL SIGNAL GENERATOR, MSK MODULATING METHOD AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an MSK modulator or the like for more exact MSK modulation with the high speed data in digital form. ;SOLUTION: When the digital signal of a modulation object is supplied, a bidirectional shift register 4 cyclically shifts a bit stream in the direction according to the logical value of this digital signal. A phase rotating direction inversion detector 2 detects a change in the logical value of this digital signal and according to this detected result, a latch limiter 3 permits/inhibits updating of stored contents of the latch part in the bidirectional shift register 4. When updating is permitted, the latch part stores the logical values of respective low-order 5th-12th and 1st-8th bits of the bit stream. Weighing adders 5I and 5Q generate two analog signals by weighing and adding these two sets of logical values. These analog signals are multiplied in one-to-one correspondence with the signals of phase mutually differing (π/2) radian, the multiplied results are added and an MSK modulated wave signal is generated.;COPYRIGHT: (C)2001,JPO