Mapping method of code word with QAM modulation
AssigneeHitachi, Ltd.
InventorsSeishi Hanaoka, Takashi Yano
Life of this patent
Estimating the term…
Abstract
In the code word mapping operation of a radio communication system, mapping patterns are provided for different S/N ratios, the code word bits produced from a coder are not equally assigned to multi-level modulation bits, but weighted according to the resistance of multi-level modulation bits to error before being assigned, and the mapping patterns are switched in accordance with S/N. Since the code word mapping method is updated so that the error rate can be always minimized according to the situations of a propagation path and S/N ratio, communication can be made with high communication quality.
Claims5
A communication method using a multi-level modulation system comprising the steps of:
- on a transmission side, coding M-bit data into N-bit data (where M≦N);
- selectively rearranging (interleaving) said N-bit data;
- and
- modulating said N-bit data into symbols of a plurality of bits each, and transmitting;
- and
- on a receiving side, demodulating said received symbols into said N-bit data;
- selectively rearranging (deinterleaving) said demodulated N-bit data;
- and
- decoding said N-bit data into said M-bit data.
A transmission-side communication apparatus in a radio communication system using a multi-level modulation system, comprising:
- a coder for converting M-bit data into N-bit data (where M≦N);
- an interleaver for rearranging (interleaving) said N-bit data produced from said coder;
- a multi-level modulator for converting said N-bit data into symbols of a multi-level each;
- and
- a controller for switching the presence/absence of interleaving said N-bit data.
A receiving-side communication apparatus in a radio communication system having a multi-level modulation system, comprising:
- a demodulator for demodulating received symbols of a multi-level each into N-bit data;
- a deinterleaver for rearranging (deinterleaving) said N-bit data;
- a decoder for converting said N-bit data into M-bit data (where M≦N);
- and
- a controller for switching the presence/absence of deinterleaving said N-bit data.
Dependencies are inferred from the claim text.