1. Field of the Invention
The present invention pertains to digital communication systems and in particular to digital receiver systems which use imbedded time-domain pilot components to facilitate recovery of information components.
2. Description of the Related Art
The present invention is directed to communication systems in which an information signal is modulated onto a carrier signal and is transmitted to a remote location where the information signal is demodulated and recovered. Various modulation schemes have been employed to increase the information handling capacity of the communication path. One notable example is the 16 point Quadrature Amplitude Modulation (QAM) approach which provides a constellation of modulation values defined by phase and amplitude, which represent information bits. Such QAM signals typically transmitted in conjunction with a pilot component. Pilot components may be employed to support synchronization and to otherwise support recovery of information components of the QAM signal which are broadcast in conjunction with one or more pilot tones that are offset in frequency from the content of the information component. Unfortunately, the multiplicity of pilot references needed to support recovery of information packets consume bandwidth which could otherwise be devoted to information content. Improvements to through-put capacity of communication systems is desirable and techniques for increasing through-put are continually sought.
USPTO Backgrounds
USPTO Backgrounds