Invention Grant
- Patent Title: QAM phase error detector
- Patent Title (中): QAM相位误差检测器
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Application No.: US12000027Application Date: 2007-12-07
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Publication No.: US07940861B2Publication Date: 2011-05-10
- Inventor: Håkan Grenabo
- Applicant: Håkan Grenabo
- Applicant Address: CA Saint-Laurent, Quebec
- Assignee: Advantech Advanced Microwave Technologies, Inc.
- Current Assignee: Advantech Advanced Microwave Technologies, Inc.
- Current Assignee Address: CA Saint-Laurent, Quebec
- Agency: Harness, Dickey & Pierce, P.L.C.
- Main IPC: H04L27/00
- IPC: H04L27/00 ; H03K9/00

Abstract:
The present invention relates to a method for reducing cycle slips in a carrier recovery loop for a phase detector, the method comprising the steps of receiving an input signal consisting of samples, each received sample having an in-phase (I) and quadrature-phase (Q) component, providing the input signal to a phase error estimator adapted to determine a phase error estimate, providing the phase error estimate to a loop filter, and forming an output signal from the carrier recovery loop by subtracting an output from the loop filter from the input signal, wherein the phase error estimate is determined based on a combination of the amplitude and phase of the samples and a probability measure for a specifically transmitted symbol, thereby improving phase tracking performance of the carrier recovery loop.Advantages with the present invention includes reduction of cycle slips without using a high performance, and expensive, hardware solution, at the same time as it is possible to suppress the effects of decision errors which enables higher gain, thereby giving an improvement in Bit Error Rate (BER) in low SNR conditions.The present invention also relates to a corresponding phase detector.
Public/Granted literature
- US20090147839A1 QAM phase error detector Public/Granted day:2009-06-11
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