Phase pulse system and method for bandwidth and energy efficient continuous phase modulation
View Patent ↗A new pulse shape for CPM is introduced which is obtained by a linear combination of well-known RC and REC pulse shapes. The new pulse shape addresses the tradeoff between the width of the PSD main lobe and the rate of decay of the side lobe to improve the coded performance of multi-carrier systems affected by ACI. Also, a methodology is proposed to design and evaluate the performance of the new pulse shape for multi-carrier, coded systems based on the modulation constrained capacity. Furthermore, a binary convolutional code and the CPM modulator are concatenated using an S-random bit interleaver to lower the error floor. Finally, Laurent representation of the new pulse shape is suggested such that by retaining only the principal pulses at the receiver, complexity of the receiver can be reduced.
1. A device comprising:
a binary convolutional coder operable to output a binary code stream based on a source data stream; and
a continuous phase modulator operable to output a modulated signal based on the binary code stream,
wherein the modulated signal is based on a pulse shape,
wherein q av is a continuous phase modulation phase response of a pulse shape for the modulator as a function of time,
wherein q rc is a continuous phase modulation phase response of raised-cosine-shaped pulses as a function of time,
wherein q re is a continuous phase modulation phase response of rectangular-shaped pulses as a function of time,
wherein when q rc is less than q re , then q rc <q av <q re , and
wherein when q re is less than q rc , then q re <q av <q rc .
2. The device of claim 1 , wherein q av is a function of q rc and q re .
3. The device of claim 2 , wherein q av is a linear function of q rc and q re .
4. The device of claim 3 ,
wherein q av is a sum of and α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
5. The device of claim 1 , wherein q av is a linear function of q rc and q re .
6. The device of claim 5 ,
wherein q av is a sum of and α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
7. The device of claim 1 ,
wherein q av is a sum of α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
8. A method comprising:
outputting, by way of a binary convolutional coder, a binary code stream based on a source data stream; and
outputting, by way of a continuous phase modulator, a modulated signal based on the binary code stream,
wherein the modulated signal is based on a pulse shape,
wherein q av is a continuous phase modulation phase response of a pulse shape for the modulator as a function of time,
wherein q rc is a continuous phase modulation phase response of raised-cosine-shaped pulses as a function of time,
wherein q re is a continuous phase modulation phase response of rectangular-shaped pulses as a function of time,
wherein when q rc is less than q re , then q rc <q av <q re , and
wherein when q re is less than q rc , then q re <q av <q rc .
9. The method of claim 8 , wherein q av is a function of q rc and q re .
10. The method of claim 9 , wherein q av is a linear function of q rc and q re .
11. The method of claim 10 ,
wherein q av is a sum of α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
12. The method of claim 8 , wherein q av is a linear function of q rc and q re .
13. The method of claim 12 ,
wherein q av is a sum of α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
14. The method of claim 8 ,
wherein q av is a sum of α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
15. A method comprising:
receiving a modulated signal;
outputting, by way of a matched filter bank, a demodulated stream based on the modulated stream of pulses; and
outputting, by way of a binary convolutional decoder, a stream of bits based on the demodulated stream,
wherein the modulated signal is based on a pulse shape,
wherein q av is a continuous phase modulation phase response of a pulse shape for the modulator as a function of time,
wherein q rc is a continuous phase modulation phase response of raised-cosine-shaped pulses as a function of time,
wherein q re is a continuous phase modulation phase response of rectangular-shaped pulses as a function of time, and
wherein when q rc is less than q re , then q rc <q av <q re , and
wherein when q re is less than q rc , then q re <q av <q rc .
16. The method of claim 15 , wherein q av is a function of q rc and q re .
17. The method of claim 16 , wherein q av is a linear function of q rc and q re .
18. The method of claim 17 ,
wherein q av is a sum of α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .
19. The method of claim 15 , wherein q av is a linear function of q rc and q re .
20. The method of claim 19 ,
wherein q av is a sum of α rc q rc and α re q re ,
wherein 0<α rc <1, and
wherein 0<α re <1−α rc .