Improving hierarchical 8psk performance
First Claim
1. A method for demodulating and decoding a hierarchically modulated signal having a first modulation at a first hierarchical level and a second modulation at a second hierarchical level, comprising the steps of:
- demodulating and processing the hierarchically modulated signal to produce symbols from the first modulation at the first hierarchical level;
applying information from a plurality of the symbols from the first modulation at the first hierarchical level in subtracting from the demodulated hierarchically modulated signal to obtain the second modulation at the second hierarchical level; and
processing the second modulation at the second hierarchical level to produce second symbols from the demodulated second signal;
wherein the hierarchically modulated signal comprises a non-uniform eight phase shift keyed signal.
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Abstract
A method and receiver systems for demodulating and decoding a hierarchically modulated signal, e.g. an 8PSK signal, are disclosed. An exemplary method includes demodulating and processing (502) the hierarchically modulated signal (202) to produce symbols (212) from the first modulation at the first hierarchical level, applying information (504) from a plurality of the symbols from the first modulation at the first hierarchical level in subtracting (214) from the demodulated hierarchically modulated signal to obtain the second modulation at the second hierarchical level and processing (506) the second modulation at the second hierarchical level to produce second symbols (222) from the demodulated second signal. The hierarchically modulated signal comprises a non-uniform 8PSK signal. Applying the information from the plurality of the symbols from the first modulation can be achieved by applying the symbols after error correction. A decision-directed demodulation of the first modulation can also be used to further improve performance.
175 Citations
18 Claims
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1. A method for demodulating and decoding a hierarchically modulated signal having a first modulation at a first hierarchical level and a second modulation at a second hierarchical level, comprising the steps of:
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demodulating and processing the hierarchically modulated signal to produce symbols from the first modulation at the first hierarchical level;
applying information from a plurality of the symbols from the first modulation at the first hierarchical level in subtracting from the demodulated hierarchically modulated signal to obtain the second modulation at the second hierarchical level; and
processing the second modulation at the second hierarchical level to produce second symbols from the demodulated second signal;
wherein the hierarchically modulated signal comprises a non-uniform eight phase shift keyed signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A receiver system for demodulating and decoding a hierarchically modulated signal having a first modulation at a first hierarchical level and a second modulation at a second hierarchical level, comprising:
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a first demodulator for demodulating the first modulation of the hierarchically modulated signal;
a symbol decoder, communicatively coupled to the first demodulator, for producing symbols from the demodulated first signal;
an error decoder, communicatively coupled to the symbol decoder, for producing an error corrected symbol stream from the symbols from the demodulated first signal;
a re-encoder for re-encoding the error corrected symbol stream;
a subtractor, communicatively coupled to the re-encoder and the first demodulator, for subtracting the re-encoded symbol stream from the first signal to produce a second signal; and
a second symbol decoder, communicatively coupled to the subtractor for producing second symbols from the second signal. - View Dependent Claims (10, 11, 12, 17)
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13. A receiver system for demodulating and decoding a hierarchically modulated signal having a first modulation at a first hierarchical level and a second modulation at a second hierarchical level, comprising:
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a first demodulator for demodulating the first modulation of the hierarchically modulated signal;
a symbol decoder, communicatively coupled to the first demodulator, for producing symbols from the demodulated first signal;
an error decoder, communicatively coupled to the symbol decoder, for producing an error corrected symbol stream from the symbols from the demodulated first signal;
a re-encoder for re-encoding the error corrected symbol stream;
an error correcting demodulator, communicatively coupled to the re-encoder for demodulating the hierarchical signal using the error corrected and re-encoded symbols from the demodulated first signal;
a subtractor, communicatively coupled to the re-encoder and the an error correcting demodulator, for subtracting the re-encoded symbol stream from the error correcting demodulated hierarchical signal to produce a second signal; and
a second symbol decoder, communicatively coupled to the subtractor for producing second symbols from the second signal. - View Dependent Claims (14, 15, 16, 18)
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Specification