Amplifiers – Hum or noise or distortion bucking introduced into signal...
Reexamination Certificate
2005-07-26
2005-07-26
Choe, Henry (Department: 2817)
Amplifiers
Hum or noise or distortion bucking introduced into signal...
C330S151000
Reexamination Certificate
active
06922103
ABSTRACT:
A method and apparatus for reducing intermodulation distortion is disclosed. In one embodiment, the method comprises the steps of accepting a sampled input signal V(t) wherein the input signal V(t) comprises a plurality of peaks; determining n peaks Vp1,Vp2, . . . Vpnof the sampled input signal V(t) exceeding a clip value Vclipat times t1, t2, . . . tn; and modifying the sampled input signal V(t) by weighting the n peaks Vp1,Vp2, . . . ,Vpnexceeding the clip value Vclipof the sampled input signal V(t) by a function b(t) wherein b(t) is either a hard limiting function or b(t)=f(a1, a2, . . . an;t−tp1,t−tp2, . . . t−tpn), wherein a1,a2, . . . anare weight values corresponding to the n peaks Vp1, Vp2, . . . Vpn, and f(t−tp1,t−tp2, . . . t−tpn) is a smooth shaping function. Intermodulation performance is then selectively improved in selected sub-bands by notch filtering prior to application to the non-linearity.
REFERENCES:
patent: 6587514 (2003-07-01), Wright et al.
patent: 6657493 (2003-12-01), Ode et al.
patent: 6717464 (2004-04-01), Fudaba et al.
Jacky S. Chow et al., “Mitigating Clipping Noise in Multi-carrier Systems,” IEEE, 1997, pp 715-719.
R. O'Neill et al., “Envelope Variations and Spectral Splatter in Clipped Multicarrier Signals,” IEEE, 1995, pp 71-75.
Mathias Pauli et al., “On the Reduction of the Out-of-Band Radiation of OFDM-Signals,” IEEE, 1998, pp 1304-1308.
Cheung Peter Y.
Crampton David L.
Liu Kuang Yung
Vollbrecht Jennifer Y.
Wah Lauriston Chin
Gates & Cooper LLP
The Boeing Company
LandOfFree
Method and apparatus for low intermodulation distortion... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for low intermodulation distortion..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for low intermodulation distortion... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3417958