Patent ID: 8761311
Filing Date: 2014-06-24
Classification: H04L

Abstract:
1. Apparatus for use in a receiver, the apparatus comprising; a staggered quadrature amplitude modulator for providing a staggered quadrature amplitude modulated signal from a received signal; a carrier tracking loop, for tracking a carrier frequency in the staggered quadrature amplitude modulated signal; and a data-aided symbol timing recovery loop for tracking symbol timing in the staggered quadrature amplitude modulated signal wherein the symbol timing recovery loop includes a filter for removing a phase response symmetry in a signal derived from the staggered quadrature amplitude modulated signal for providing a filter output signal, wherein the filter is sensitive to a timing phase offset, while keeping the filter insensitive to a carrier phase offset, and wherein the filter comprises a Hilbert filter that operates on a real signal component of the signal derived from the staggered quadrature amplitude modulated signal; and a timing phase detector responsive to the filter output signal for driving the symbol timing recovery loop.