Bi-directional vector rotator

A method for generating phase rotated signals in clockwise and counter clockwise directions, the method comprising:

• receiving a complex input having real and imaginary components;
• receiving a complex carrier signal having real and imaginary components;
• generating a set of product terms based on the complex input and the complex carrier signal, wherein each product term is representative of a particular combination of a real or imaginary component of the complex input with a real or imaginary component of the complex carrier signal;
• selectively combining the product terms to generate a first complex output having a phase that is rotated in the clockwise direction relative to that of the complex input;
• and
• selectively combining the product terms to generate a second complex output having a phase that is rotated in the counter clockwise direction relative to that of the complex input.

A receiver comprising:

• a front-end unit operative to receive, condition, and digitize a received signal to provide a complex input signal;
• and
• a bi-directional vector rotator coupled to the front-end unit and operative to multiply the complex input signal with a first complex carrier signal to provide first and second complex outputs, wherein the first complex output has a phase that is rotated in a first direction relative to that of the complex input signal, and wherein the second complex output has a phase that is rotated in a second direction relative to that of the complex input signal,
• wherein the received signal includes three modulated signals centered at first, second, and third frequencies, and wherein the first complex output corresponds to the modulated signal centered at the first frequency and the second complex output corresponds to the modulated signal centered at the third frequency.

A receiver comprising:

• a front-end unit operative to receive, condition, and digitize a received signal to provide a complex input signal;
• and
• a bi-directional vector rotator coupled to the front-end unit and operative to multiply the complex input signal with a first complex carrier signal to provide first and second complex outputs, wherein the first complex output has a phase that is rotated in a first direction relative to that of the complex input signal, and wherein the second complex output has a phase that is rotated in a second direction relative to that of the complex input signal,
• wherein the received signal includes three modulated signals centered at first, second, and third frequencies, and wherein the first complex output corresponds to the modulated signal centered at the first frequency and the second complex output corresponds to the modulated signal centered at the third frequency,
• wherein the first, second, and third frequencies are separate by a particular sub-carrier frequency, fsc, and wherein the complex input signal comprises complex samples having a sample rate, fs, that is a multiple of four times the sub-carrier frequency.

A receiver comprising:

• a front-end unit operative to receive, condition, and digitize a received signal to provide a complex input signal;
• and
• a bi-directional vector rotator coupled to the front-end unit and operative to multiply the complex input signal with a first complex carrier signal to provide first and second complex outputs wherein the first complex output has a phase that is rotated in a first direction relative to that of the complex input signal, and wherein the second complex output has a phase that is rotated in a second direction relative to that of the complex input signal,
• wherein the received signal includes three modulated signals centered at first, second, and third frequencies, and wherein the first complex output corresponds to the modulated signal centered at the first frequency and the second complex output corresponds to the modulated signal centered at the third frequency,
• wherein the three modulated signals conforms to a multi-carrier signal defined by CDMA-2000 standard.