Phase angle detector and frequency discriminator employing the same

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said I channel signal and said Q channel signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for generating −i (or −q),
• a second calculation section for generating 2lm+i (or 2lm+q) (lm is an amplitude value for a signal point), and
• a third operation section for generating −2lm+i (or −2lm+q),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first to said third calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said I channel signal and said Q channel signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle operating section, receiving said I (or Q) channel signal and including
• a first calculation section for outputting said I (or Q) channel signal unchanged,
• a second calculation section for generating 2lm−i (or 2lm−q) (lm is an amplitude value for a signal point), and
• a third calculation section for generating −2lm−i (or −2lm−q),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first to said third calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said Q (or I) signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for generating lm+i (or lm+q) (lm is an amplitude for said signal point), and
• a second calculation section for generating −(lm+i) (or −(lm+q)),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first or said second calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said Q (or I) signal, detection a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for generating lm−i (or lm−q) (lm is an amplitude for said signal point), and
• a second calculation section for generating −(lm−i) (or −(lm−q)),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first or said second calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said I channel signal and said Q channel signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for generating −i (or −q),
• a second calculation section for generating 2lm+i (or 2lm+q) (lm is an amplitude value for a signal point), and
• a third calculation section for generating 4lm−i (or 4lm−q),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first to said third calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said I channel signal and said Q channel signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for outputting said I (or Q) channel signal unchanged,
• a second calculation section for generating 2lm−i (or 2lm−q) (lm is an amplitude value for a signal point), and
• a third calculation section for generating 4lm+i (or 4lm+q),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first to said third calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said Q (or I) signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for generating lm+i (or lm+q) (lm is an amplitude for said signal point), and
• a second calculation section for generating 3lm−i (or 3lm−q),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first or said second calculation sections.

A phase angle detector, which detects a phase angle on a phase plane for a signal point specified by an I channel signal and a Q channel signal, comprising:

• a quadrant detection section for, in response to said Q (or I) signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal;
• and
• a phase angle calculating section, receiving said I (or Q) channel signal and including
• a first calculation section for generating lm−i (or lm−q) (lm is an amplitude for said signal point), and
• a second calculation section for generating 3lm+i (or 3lm+q),
• for, in response to said quadrant detection signal, selectively outputting one of the products of said first or said second calculation sections.

A frequency discriminator, for detecting a frequency difference between a quadrature amplitude modulation carrier and a demodulation reference carrier, comprising:

• a phase angle detector, including
• a quadrant detection section for, in response to at least one of said I channel signal and said Q channel signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal, and
• a phase angle calculating section for performing an calculation using said I channel signal or said Q channel signal in response to said quadrant detection signal to convert said phase angle on said phase plane into a phase angle for a predetermined one-dimensional coordinate;
• and
• an integration circuit for receiving said phase angle for said one-dimensional coordinate, which is obtained by said phase angle detector, and for, when signal points outside a predetermined mask circle S are sequentially demodulated, accumulating a phase angle difference between said signal points.

A frequency discriminator, for detecting a frequency difference between a quadrature amplitude modulation carrier and a demodulation reference carrier, comprising:

• a phase angle detector, including
• a quadrant detection section for, in response to at least one of said I channel signal and said Q channel signal, detecting a quadrant on said phase plane for said signal point and for generating a quadrant detection signal, and
• a first phase angle calculating section for performing an calculation using said I channel signal in response to said quadrant detection signal to convert said phase angle on said phase plane into a phase angle for a first predetermined one-dimensional coordinate, and
• a second phase angle calculating section for performing an calculation using said Q channel signal in response to said quadrant detection signal to convert said phase angle on said phase plane into a phase angle for a second predetermined one-dimensional coordinate, and
• and integration circuit for receiving said phase angles for said first and said second one-dimensional coordinates, which are obtained by said phase angle detector, and for, when signal points outside a predetermined mask circle S are sequentially demodulated, accumulating phase angle difference between said signal points.