| 摘要 |
A bi-directional vector rotator that can be used to provide outputs having phases that are rotated in clockwise and counter clockwise directions relative to that of the input signal. The bi-directional vector rotator includes a product term generator that receives a complex input and a complex carrier signal and generates product terms. Combiners then selectively combine the product terms to generate the outputs. By sharing the same product term generator for both clockwise and counter clockwise phase rotations, the bi-directional vector rotator can be implemented using less circuitry than that for a conventional design employing two uni-directional vector rotators. Moreover, only one complex carrier signal is needed by the bi-directional vector rotator instead of two for the conventional design. Further simplification in the design of the bi-directional vector rotator can be achieved by selecting the proper sampling rate for the complex input. The bi-directional vector rotator can be advantageously used in a receiver device, and is especially efficient in demodulating a multi-carrier signal having multiple (e.g., three) modulated signals. |
