Hamming coded modulation
An optical system may include a digital signal processor (DSP) to receive first samples of a digital signal. The first samples may be Hamming encoded. The DSP may correlate the first samples to multiple groups of second samples to determine multiple correlation values. Each of the multiple groups of second samples may correspond to respective code words. Each of the multiple correlation values may correspond to a correlation measurement between the first samples and each of the multiple groups of second samples. The DSP may determine a particular code word, of the multiple code words, corresponding to one of the correlation values of the multiple correlation values; determine output bits based on bits of the particular code word and the one of the correlation values; and provide the output bits. The output bits may include data associated with the digital signal.
1. An optical system comprising:
a digital signal processor (DSP) configured to:
receive first samples of a digital signal,
the first samples of the digital signal being Hamming encoded,
correlate the first samples to a plurality of groups of second samples to determine a plurality of correlation values,
each of the plurality of groups of second samples corresponding to a respective plurality of code words,
each of the plurality of correlation values corresponding to a correlation measurement between the first samples and each of the plurality of groups of second samples,
determine a particular code word, of the plurality of code words, corresponding to one of the correlation values of the plurality of correlation values,
determine output bits based on bits of the particular code word and the one of the correlation values, and
provide the output bits,
the output bits including data associated with the digital signal;
a local oscillator configured to provide a reference optical signal;
a hybrid mixer configured to:
receive an input signal,
receive the reference signal, and
provide an optical signal corresponding to the input signal and the reference signal,
a photodetector configured to:
receive the optical signal and
provide a voltage signal corresponding to the optical signal; and
an analog-to-digital converter (ADC) configured to:
receive the voltage signal, and
provide the digital signal based on receiving the voltage signal,
where when receiving the samples of the digital signal, the DSP is further configured to receive the samples of the digital signal based on the digital signal provided by the ADC.
2. The optical system in accordance with claim 1 , where the DSP is further configured to:
determine a plurality of competing values based on the bits of the particular code word, and based on the plurality of correlation values,
where when determining the output bits, the DSP is configured to determine the output bits further based on the plurality of competing values.
3. The optical system in accordance with claim 1 , where the first samples are (8,4) Hamming encoded.
4. The optical system in accordance with claim 1 , where the output bits include a first set of output bits and a second set of output bits,
where the DSP is further configured to:
provide the first set of output bits and the second set of output bits to a de-interleaver to cause the de-interleaver to form a first frame and a second frame,
the first frame including a first bit, of the first set of output bits, and a first bit, of the second set of output bits,
the second frame including a second bit, of the first set of output bits, and a second bit, of the second set of output bits.
5. The optical system in accordance with claim 1 , where the plurality of correlation values corresponds to respective Euclidean distance measurements between the first samples and each of the plurality of groups of second samples,
where the one of the correlation values corresponds to a minimum Euclidean distance between the first samples and second samples of the particular code word.
6. The optical system in accordance with claim 1 , further comprising:
a filter configured to:
receive the first samples,
reduce timing skews associated with the first samples,
reduce chromatic dispersion associated with the first samples, and
provide the first samples after reducing the timing skews and the chromatic dispersion,
where when receiving the first samples, the DSP is further configured to receive the first samples provided by the filter.
7. An optical system comprising:
a first digital signal processor (DSP) configured to:
receive first samples of a digital signal,
the first samples of the digital signal being Hamming encoded,
correlate the first samples to a plurality of groups of second samples to determine a plurality of correlation values,
each of the plurality of groups of second samples corresponding to a respective plurality of code words,
each of the plurality of correlation values corresponding to a correlation measurement between the first samples and each of the plurality of groups of second samples,
determine a particular code word, of the plurality of code words, corresponding to one of the correlation values of the plurality of correlation values,
determining output bits based on bits of the particular code word and the one of the correlation values, and
provide the output bits, the output bits including data associated with the digital signal;
a second DSP configured to:
receive a group of input bits,
encode the group of input bits using an (8,4) Hamming encoder, and
provide symbols, associated with the group of input bits based on encoding the group of input bits;
a digital-to-analog-converter (DAC), configured to:
receive the symbols, and
provide a voltage corresponding to the symbols;
a laser configured to provide an input optical signal; and
a modulator configured to:
receive the voltage and the input optical signal,
modulate the input optical signal based on the voltage to form an output signal, and
provide the output signal,
where the digital signal corresponds to the output signal.
8. The optical system in accordance with claim 7 , where the DSP is further configured to:
determine a plurality of competing values based on the bits of the particular code word, and based on the plurality of correlation values,
where when determining the output bits, the DSP is configured to determine the output bits further based on the plurality of competing values.
9. The optical system in accordance with claim 7 , where the first samples are (8,4) Hamming encoded.
10. The optical system in accordance with claim 7 , where the output bits include a first set of output bits and a second set of output bits,
where the DSP is further configured to:
provide the first set of output bits and the second set of output bits to a de-interleaver to cause the de-interleaver to form a first frame and a second frame,
the first frame including a first bit, of the first set of output bits, and a first bit, of the second set of output bits,
the second frame including a second bit, of the first set of output bits, and a second bit, of the second set of output bits.
11. The optical system in accordance with claim 7 , where the plurality of correlation values corresponds to respective Euclidean distance measurements between the first samples and each of the plurality of groups of second samples,
where the one of the correlation values corresponds to a minimum Euclidean distance between the first samples and second samples of the particular code word.
12. The optical system in accordance with claim 7 , further comprising:
a filter configured to:
receive the first samples,
reduce timing skews associated with the first samples,
reduce chromatic dispersion associated with the first samples, and
provide the first samples after reducing the timing skews and the chromatic dispersion,
where when receiving the first samples, the DSP is further configured to receive the first samples provided by the filter.
13. An optical system comprising:
a first digital signal processor (DSP) configured to:
receive a group of input bits,
encode the group of input bits using an (8,4) Hamming encoder, and
provide symbols, associated with the group of input bits based on encoding the group of input bits;
a digital-to-analog-converter (DAC) configured to:
receive the symbols, and
provide a voltage corresponding to the symbols;
a laser configured to provide an input optical signal;
a modulator configured to:
receive the voltage and the input optical signal,
modulate the input optical signal based on the voltage to form an output signal, and
provide the output signal;
a second DSP configured to:
receive first samples of a digital signal corresponding to the output signal,
correlate the first samples to a plurality of groups of second samples to determine a plurality of correlation values,
each of the plurality of groups of second samples corresponding to a respective plurality of code words,
each of the plurality of correlation values corresponding to a correlation measurement between the first samples and each of the plurality of groups of second samples,
determine a particular code word, of the plurality of code words, corresponding to one of the correlation values of the plurality of correlation values,
determine output bits based on bits of the particular code word and the one of the correlation values, and
provide the output bits,
the output bits including data associated with the output signal.
14. The optical system in accordance with claim 13 , where the second DSP is further configured to:
determine a plurality of competing values based on the bits of the particular code word and based on the plurality of correlation values,
where when determining the output bits, the second DSP is configured to determine the output bits further based on the plurality of competing values.
15. The optical system in accordance with claim 13 , where the output bits include a first set of output bits and a second set of output bits,
where the second DSP is further to:
provide the first set of output bits and the second set of output bits to a de-interleaver to cause the de-interleaver to form a first frame and a second frame,
the first frame including a first bit, of the first set of output bits, and a first bit, of the second set of output bits, and
the second frame including a second bit, of the first set of output bits, and a second bit, of the second set of output bits.
16. The optical system in accordance with claim 13 , where the plurality of correlation values corresponds to respective Euclidean distance measurements between the first samples and each of the plurality of groups of second samples,
where the one of the correlation values corresponds to a minimum Euclidean distance between the first samples and second samples of the particular code word.
17. The optical system in accordance with claim 13 , further comprising:
a filter configured to:
receive the first samples,
reduce timing skews associated with the first samples,
reduce chromatic dispersion associated with the first samples, and
provide the first samples after reducing the timing skews and the chromatic dispersion,
where when receiving the first samples, the second DSP is further configured to receive the first samples provided by the filter.
18. The optical system in accordance with claim 13 , further comprising:
a local oscillator configured to provide a reference optical signal;
a hybrid mixer configured to:
receive the output signal,
receive the reference signal, and
provide an optical signal corresponding to the input signal and the reference signal,
a photodetector configured to:
receive the optical signal, and
provide a voltage signal corresponding to the optical signal; and
an analog-to-digital converter (ADC) configured to:
receive the voltage signal, and
provide the digital signal based on receiving the voltage signal,
where when receiving the samples of the digital signal, the second DSP is further configured to receive the samples of the digital signal based on the digital signal provided by the ADC.
19. An optical system comprising:
a local oscillator configured to provide a reference optical signal;
a hybrid mixer configured to:
receive an input signal,
receive the reference signal, and
provide an optical signal corresponding to the input signal and the reference signal,
a photodetector configured to:
receive the optical signal, and
provide a voltage signal corresponding to the optical signal;
an analog-to-digital converter (ADC) configured to:
receive the voltage signal, and
provide the digital signal based on receiving the voltage signal;
a digital signal processor (DSP) configured to:
receive first samples of the digital signal,
the first samples of the digital signal being Hamming encoded,
correlate the first samples to a plurality of groups of second samples to determine a plurality of correlation values,
each of the plurality of groups of second samples corresponding to a respective plurality of code words,
each of the plurality of correlation values corresponding to a correlation measurement between the first samples and each of the plurality of groups of second samples,
determine a particular code word, of the plurality of code words, corresponding to one of the correlation values of the plurality of correlation values,
determine output bits based on bits of the particular code word and the one of the correlation values, and
provide the output bits,
the output bits including data associated with the digital signal.
20. The optical system in accordance with claim 19 , where the DSP is further configured to:
determine a plurality of competing values based on the bits of the particular code word and based on the plurality of correlation values,
where when determining the output bits based, the DSP is configured to determine the output bits further based on the plurality of competing values.
21. The optical system in accordance with claim 19 , where the first samples are (8,4) Hamming encoded.
22. The optical system in accordance with claim 19 , where the output bits include a first set of output bits and a second set of output bits,
where the DSP is further to:
provide the first set of output bits and the second set of output bits to a de-interleaver to cause the de-interleaver to form a first frame and a second frame,
the first frame including a first bit, of the first set of output bits, and a first bit, of the second set of output bits, and
the second frame including a second bit, of the first set of output bits, and a second bit, of the second set of output bits.
23. The optical system in accordance with claim 19 , where the plurality of correlation values corresponds to respective Euclidean distance measurements between the first samples and each of the plurality of groups of second samples,
where the highest correlation value corresponds to a minimum Euclidean distance between the first samples and second samples of the particular code word.
24. The optical system in accordance with claim 19 , where the DSP is a first DSP,
the optical system further comprising:
a second DSP configured to:
receive a group of input bits,
encode the group of input bits using an (8,4) Hamming encoder, and
provide symbols associated with the group of input bits based on encoding the group of input bits;
a digital-to-analog-converter (DAC) configured to:
receive the symbols, and
provide a voltage corresponding to the symbols;
a laser configured to provide an input optical signal; and
a modulator configured to:
receive the voltage and the input optical signal,
modulate the input optical signal based on the voltage to form an input signal, and
provide the input signal to the hybrid mixer.