Claims
- 1. A distortion compensating device provided in a receiver for compensating distortion added to a signal in a transmission path, said signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of a plurality of specified signal points in a signal space diagram, said distortion compensation device comprising:distortion-compensated signal calculating means for producing a distortion-compensated signal S based on an equation S=V−α1V−α2V2 −α3V3. . ., where V denotes a received signal, and αn is a given factor; anddiscrimination means for discriminating the distortion-compensated signal S based on a threshold.
- 2. The distortion compensating device as claimed in claim 1, wherein said distortion-compensated signal calculating means comprises:two calculating sections calculating said equation in in-phase and quadrature-phase channels respectively, wherein received signal information of the in-phase channel is used for a calculation in both the in-phase and quadrature-phase channels, and received signal information of the quadrature-phase channel is used for the calculation in both the in-phase and quadrature-phase channels.
- 3. The distortion compensating device as claimed in claim 2, wherein said given factor of the distortion-compensated signal calculating means is selected so as to minimize a correlation between a square of the received signal vector V and an error signal indicating a relationship between the distortion-compensated signal S and the specified signal point in the space diagram.
- 4. The distortion compensating device as claimed in claim 1, wherein said given factor αn of the distortion-compensated signal calculating means is selected as to minimize a correlation between a square of the received signal vector V and an error signal indicating a relationship between the distortion-compensated signal S and the specified signal point in the space diagram.
- 5. The distortion compensating device as claimed in claim 4, wherein said distortion-compensated signal calculating means comprises:factor calculating means for calculating said correlation.
- 6. A distortion compensating device provided in a receiver for compensating distortion added to a signal in a transmission path, said signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of a plurality of specified signal points in a signal space diagram, said distortion compensation device comprising:a circuit section producing a distortion-compensated signal S based on an equation S=V−α1V−α2V2 −α3V3. . ., where V denotes a received signal, and αn denotes a given factor; anda discrimination circuit discriminating the distortion-compensated signal S based on a threshold.
Priority Claims (1)
Number |
Date |
Country |
Kind |
6-303926 |
Dec 1994 |
JP |
|
Parent Case Info
This application is a divisional application of a U.S. patent application Ser. No. 08/526,766 filed Sep. 11, 1995, now U.S. Pat. No. 6,201,841.
US Referenced Citations (8)