Uplink Modulation

WCDMA uses Quadrature Phase Shift Keying
(QPSK) modulation in the uplink. This technique is depicted in Figure
6-5. The stream of spread and scrambled signals, such as the output
shown in Figure 6-2, forms the complex-valued input stream of chips. The
real and imaginary parts are separated, with the real part of a given complex
chip forming the in-phase (I) branch and the imaginary part forming
the quadrature phase (Q) branch in the modulator.