Multilevel amplitude modulation device, multilevel amplitude demodulation device, transmission system including these, multilevel amplitude modulation method, and multilevel amplitude demodulation method
First Claim
1. A multilevel amplitude modulation device for generating, from digital data, a multilevel amplitude modulation signal having four or more signal levels and outputting the generated signal, the modulation device comprising:
- an average level calculator operable to select one of a plurality of preliminarily prepared different candidates for a code word building method such that an average signal level of a symbol array, obtained by adding a symbol for a code word of digital data to be transmitted to one or more already outputted symbols included in a multilevel amplitude modulation signal already outputted, is most approximate to voltage center of the four or more signal levels, and output a selection signal indicating the selected code word building method;
a signal converter operable to form a code word of the digital data in accordance with the code word building method indicated by the selection signal; and
a multilevel modulator operable to generate a multilevel amplitude modulation signal with use of the code word and output the generated multilevel amplitude modulation signal.
3 Assignments
0 Petitions
Accused Products
Abstract
A multilevel amplitude modulation device for generating, from digital data, a multilevel amplitude modulation signal having four or more signal levels and outputting the generated signal, including: an average level calculator that selects one of a plurality of preliminarily prepared different candidates for a code word building method such that average level of a symbol array, obtained by adding a symbol for a code word of digital data to be transmitted to one or more already outputted symbols included in a multilevel amplitude modulation signal already outputted, is most approximate to voltage center of the four or more signal levels, and outputs a selection signal indicating the selected method; a signal converter that forms a codeword of the digital data in accordance with the method indicated by the selection signal; and a multilevel modulator that generates a multilevel amplitude modulation signal using the codeword and outputs the generated signal.
22 Citations
11 Claims
-
1. A multilevel amplitude modulation device for generating, from digital data, a multilevel amplitude modulation signal having four or more signal levels and outputting the generated signal, the modulation device comprising:
-
an average level calculator operable to select one of a plurality of preliminarily prepared different candidates for a code word building method such that an average signal level of a symbol array, obtained by adding a symbol for a code word of digital data to be transmitted to one or more already outputted symbols included in a multilevel amplitude modulation signal already outputted, is most approximate to voltage center of the four or more signal levels, and output a selection signal indicating the selected code word building method; a signal converter operable to form a code word of the digital data in accordance with the code word building method indicated by the selection signal; and a multilevel modulator operable to generate a multilevel amplitude modulation signal with use of the code word and output the generated multilevel amplitude modulation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A multilevel amplitude modulation method executed by a modulation device, of generating, from digital data, a multilevel amplitude modulation signal having four or more signal levels and outputting the generated signal, the method comprising:
-
receiving digital data to be transmitted; selecting one of a plurality of preliminarily prepared different candidates for a code word building method such that an average signal level of a symbol array, obtained by adding a symbol for a code word of the digital data to one or more already outputted symbols included in a multilevel amplitude modulation signal already outputted, is most approximate to voltage center of the four or more signal levels, and generating a multilevel amplitude modulation signal with use of the code word of the data formed in accordance with the code word building method thus selected, and outputting the generated signal.
-
Specification