| 摘要 |
A carrier recovery circuit which phase aligns receiver-generated, quadrature-related carrier signals to incoming modulated, quadrature-related carrier signals is disclosed. The amplitudes of these modulated carriers determine data points in a signal-space diagram. In the carrier recovery circuit, the amplitude of each of said modulated carrier signals is sensed relative to thresholds which pass through the outermost data points in the signal-space diagram. These outermost data points form a periphery when interconnected by straight lines which encompass all of the data points. A phase error signal is generated which maintains phase alignment of the receiver-generated carriers to the incoming carriers when the sensed amplitudes fall in selected regions of the signal-space diagram lying outside of the aforementioned periphery. |
