Radio communication device and radio communication method

Patent metadata

Field	Value
Publication number	US-9954702-B2
Application number	US-201715415320-A
Country	US
Kind code	B2
Filing date	Jan 25, 2017
Priority date	Aug 7, 2014
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A radio communication device has a local oscillator to generate a local signal, a first mixer to mix a binary continuous phase frequency shift keying signal and the local signal so as to generate a baseband signal, a first filter to remove an unnecessary frequency component included in the baseband signal, a delay device to delay an output signal of the first filter by one symbol, and a wave detector to demodulate the continuous phase frequency shift keying signal, wherein a modulation index m of the continuous phase frequency shift keying signal is a value expressed by m=n+k where 0<n<1 is satisfied and k is an integer of 0 or more, and a frequency of the local signal is a frequency shifted by a frequency corresponding to 0 or 1 of the continuous phase frequency shift keying signal.

First claim

The invention claimed is:

1. A radio communication device comprising:
a local oscillator to generate a local signal;
a first mixer to mix a binary continuous phase frequency shift keying signal and the local signal so as to generate a baseband signal;
a first filter to remove an unnecessary frequency component included in the baseband signal;
a delay circuitry to delay an output signal of the first filter by one symbol; and
a wave detector to demodulate the phase-continuous frequency shift keying signal by using the output signal of the first filter and an output signal of the delay circuitry,
wherein a modulation index m of the phase-continuous frequency shift keying signal is a value expressed by m=n+k where 0<n<1 is satisfied and k is an integer of 0 or more,
a frequency of the local signal is a frequency shifted by a frequency corresponding to 0 or 1 of the continuous phase frequency shift keying signal, from a carrier frequency of the continuous phase frequency shift keying signal,
the output signal of the first filter is a signal including a phase that remains when the continuous phase frequency shift keying signal is one of 0 and 1 and that shifts by π when the signal is another, for each symbol.

2. The radio communication device according to claim 1 ,
wherein the continuous phase frequency shift keying signal is a signal including a phase that varies by π/2 when the continuous phase frequency shift keying signal is one of 0 and 1 and a phase that varies by −π/2 when the signal is another, for each symbol.

3. The radio communication device according to claim 1 , further comprising:
a phase shifter to shift a phase of the local signal by π/2;
a second mixer to mix the continuous phase frequency shift keying signal and an output signal of the phase shifter so as to generate a signal having a phase orthogonal to a phase of the signal mixed by the first mixer;
a second filter to remove an unnecessary frequency component included in the output signal of the second mixer;
a symbol synchronizing circuitry to detect symbol synchronization timing based on the output signal of the first filter and an output signal of the second filter;
a phase detector to detect the phase with synchronization timing based on the output signals of the first filter and the second filter; and
a phase adjuster to adjust the phase of the local signal with respect to the local oscillator such that the phase detected by the phase detector becomes 0 or π.

4. The radio communication device according to claim 3 ,
wherein the symbol synchronizing circuitry is to detect the synchronization timing based on a preamble signal, for each data series including the preamble signal and data of a plurality of symbols.

5. The radio communication device according to claim 3 , further comprising:
a phase tracking circuitry to issue an instruction for phase adjustment by 2π×(0.5−n), to the phase adjuster when detecting a variation of a phase of the output signal of the first filter based on data demodulated by the wave detector,
wherein the phase adjuster shifts the phase of the local signal by 2π×(0.5−n), to the local oscillator, in accordance with the instruction from the phase tracking circuitry.

6. The radio communication device according to claim 1 ,
wherein the n is a value in the following range: 0.4≤n≤0.6.

7. The radio communication device according to claim 1 ,
wherein the n is 0.5.

8. The radio communication device according to claim 1 ,
wherein the k is 0.

9. The radio communication device according to claim 1 ,
wherein the m is 0.5.

10. The radio communication device according to claim 1 , further comprising:
an integrated circuit including the local oscillator, the first mixer, the first filter, the delay circuitry, and the wave detector.

11. The radio communication device according to claim 1 , further comprising:
at least one antenna.

12. A radio communication device comprising:
an RF circuitry including a receiving circuit; and
a baseband circuitry including a reception processing circuit,
wherein the receiving circuit comprises:
a local oscillator to generate a local signal;
a first mixer to mix a binary continuous phase frequency shift keying signal and the local signal so as to generate a baseband signal; and
a first filter to remove an unnecessary frequency component included in the baseband signal,

the reception processing circuit comprises:
a delay circuitry to delay an output signal of the first filter by one symbol; and
a wave detector to demodulate the continuous phase frequency shift keying signal by using the output signal of the first filter and an output signal of the delay circuitry,

a modulation index m of the continuous phase frequency shift keying signal is a value expressed by m=n+k where 0<n<1 is satisfied and k is an integer of 0 or more,
a frequency of the local signal is a frequency shifted by a frequency corresponding to 0 or 1 of the continuous phase frequency shift keying signal, from a carrier frequency of the continuous phase frequency shift keying signal,
the output signal of the first filter is a signal including a phase that remains when the continuous phase frequency shift keying signal is one of 0 and 1 and that shifts by π when the signal is another, for each symbol.

13. A radio communication method comprising:
generating a baseband signal by mixing a binary continuous phase frequency shift keying signal and a local signal generated by a local oscillator;
removing an unnecessary frequency component included in the baseband signal, by a first filter;
delaying an output signal of the first filter by one symbol by a delay circuitry; and
demodulating the continuous phase frequency shift keying signal by using the output signal of the first filter and an output signal of the delay circuitry,
wherein a modulation index m of the continuous phase frequency shift keying signal is a value expressed by m=n+k where 0<n<1 is satisfied and k is an integer of 0 or more,
a frequency of the local signal is a frequency shifted by a frequency corresponding to 0 or 1 of the continuous phase frequency shift keying signal, from a carrier frequency of the continuous phase frequency shift keying signal,
the output signal of the first filter is a signal including a phase that remains when the continuous phase frequency shift keying signal is one of 0 and 1 and that shifts by π when the signal is another, for each symbol.

14. The radio communication method according to claim 13 ,
wherein the continuous phase frequency shift keying signal is a signal including a phase that varies by π/2 when the continuous phase frequency shift keying signal is one of 0 and 1 and a phase that varies by −π/2 when the signal is another, for each symbol.

15. The radio communication method according to claim 13 , further comprising:
shifting a phase of the local signal by π/2;
mixing the continuous phase frequency shift keying signal and the shifted signal so as to generate a signal having a phase orthogonal to a phase of the signal mixed by the first mixer;
removing an unnecessary frequency component included in the orthogonal signal;
detecting symbol synchronization timing by a symbol synchronizing circuitry based on the output signal of the first filter and an output signal of the second filter;
detecting the phase with synchronization timing based on the output signals of the first filter and the second filter; and
adjusting the phase of the local signal with respect to the local oscillator such that the detected phase becomes 0 or π.

16. The radio comm

Assignees

• Toshiba Kk

Inventors

• Okuni Hidenori
• Sai Akihide
• Furuta Masanori

Classifications

• H04L27/144

  with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements · CPC title

• H04L27/152

  using controlled oscillators, e.g. PLL arrangements · CPC title

• H04L27/227 Primary

  using coherent demodulation · CPC title

• H04L7/041

  using special codes as synchronising signal · CPC title