US 11,637,727 B2Granted

Modulator, demodulator and wireless communication system

AssigneeShanghai Panchip Microelectronics Co., Ltd.

InventorsChenghao Pan, Chuan Wu

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Abstract

The invention discloses a modulator, a demodulator and a wireless communication system. The wireless communication system comprises a modulator and a demodulator. The modulator is suitable for generating a target linear frequency modulation signal, wherein the target linear frequency modulation signal is a signal of which the frequency is varied linearly over time, wherein the phase of the target linear frequency modulation signal is determined by an initial frequency and a frequency stepping of the target linear frequency modulation signal, and the frequency stepping is determined by the bandwidth of the target linear frequency modulation signal and the spreading factor of the target linear frequency modulation signal. The demodulator is suitable for demodulating the target linear frequency modulation signal. According to the scheme, power consumption can be reduced while long-distance signal transmission is realized.

Claims20

Dependent claims

A modulator, wherein

the modulator is suitable for generating a target linear frequency modulation signal, wherein the target linear frequency modulation signal is a signal of which the frequency is varied linearly over time, wherein the phase of the target linear frequency modulation signal is determined by an initial frequency and a frequency stepping of the target linear frequency modulation signal, and the frequency stepping is determined by the bandwidth of the target linear frequency modulation signal and the spreading factor of the target linear frequency modulation signal;
the modulator comprises a digital modulation circuit, wherein the digital modulation circuit is suitable for generating a control signal of the target linear frequency modulation signal;
the target linear frequency modulation signal is given by
s
⁡
(
t
)
=
sin
⁡
(
2
⁢
π
×
f
⁡
(
t
)
×
t
)
,
⁢
f
⁡
(
t
)
=
f
c
+
(
f
s
⁢
t
⁢
a
⁢
r
⁢
t
+
f
s
⁢
t
⁢
e
⁢
p
2
)
+
f
s
⁢
t
⁢
e
⁢
p
2
⁢
t
,
the digital baseband signal is given by
s
⁡
(
n
)
=
sin
⁡
(
2
⁢
π
B
⁢
W
×
f
⁡
(
n
)
×
n
)
,
⁢
f
⁡
(
n
)
=
(
f
s
⁢
t
⁢
a
⁢
r
⁢
t
+
f
s
⁢
t
⁢
e
⁢
p
2
)
+
f
s
⁢
t
⁢
e
⁢
p
2
⁢
n
,
wherein 1≤n≤2SF, SF is the spreading factor;
the phase of the digital baseband signal at point m is calculated as
θ
m
=
θ
0
+
2
⁢
π
B
⁢
W
×
∑
n
=
1
m
⁢
(
f
start
+
f
s
⁢
t
⁢
e
⁢
p
×
n
)
;
wherein fc is the radio frequency, fstart is the initial frequency of the target linear frequency modulation signal, fstep is the frequency stepping of the target linear frequency modulation signal, the control signal is determined by f(n);
θm is the phase of the digital baseband signal at the point m, BW is the bandwidth of the digital baseband signal, and θ0 is an initial phase of the digital baseband signal.

174 more elements

A wireless communication system comprising a modulator and a demodulator

the modulator is suitable for generating a target linear frequency modulation signal, wherein the target linear frequency modulation signal is a signal of which the frequency is varied linearly over time, wherein the phase of the target linear frequency modulation signal is determined by an initial frequency and a frequency stepping of the target linear frequency modulation signal, and the frequency stepping is determined by the bandwidth of the target linear frequency modulation signal and the spreading factor of the target linear frequency modulation signal;
the modulator comprises a digital modulation circuit, wherein the digital modulation circuit is suitable for generating a control signal of the target linear frequency modulation signal;
the target linear frequency modulation signal is given by
s
⁡
(
t
)
=
sin
⁡
(
2
⁢
π
×
f
⁡
(
t
)
×
t
)
,
⁢
f
⁡
(
t
)
=
f
c
+
(
f
s
⁢
t
⁢
a
⁢
r
⁢
t
+
f
s
⁢
t
⁢
e
⁢
p
2
)
+
f
s
⁢
t
⁢
e
⁢
p
2
⁢
t
,
the digital baseband signal is given by
s
⁡
(
n
)
=
sin
⁡
(
2
⁢
π
B
⁢
W
×
f
⁡
(
n
)
×
n
)
,
⁢
f
⁡
(
n
)
=
(
f
s
⁢
t
⁢
a
⁢
r
⁢
t
+
f
s
⁢
t
⁢
e
⁢
p
2
)
+
f
s
⁢
t
⁢
e
⁢
p
2
⁢
n
,
wherein 1≤n≤2SF, SF is the spreading factor;
the phase of the digital baseband signal at point m is calculated as
θ
m
=
θ
0
+
2
⁢
π
B
⁢
W
×
∑
n
=
1
m
⁢
(
f
s
⁢
t
⁢
a
⁢
r
⁢
t
+
f
s
⁢
t
⁢
e
⁢
p
×
n
)
;
wherein fc is the radio frequency, fstart is the initial frequency of the target linear frequency modulation signal, fstep is the frequency stepping of the target linear frequency modulation signal, the control signal is determined by f(n);
θm is the phase of the digital baseband signal at the point m, BW is the bandwidth of the digital baseband signal, and θ0 is an initial phase of the digital baseband signal;
the demodulator is configured to receive the target linear frequency modulation signal emitted by the modulator, and is configured to demodulate the target linear frequency modulation signal;
the demodulator comprises:
a synchronous buffer, configured to store the ith sampled signal of a preset length, the preset length be determined by the spreading factor of the target linear frequency modulation signal;
a processor, coupled to the synchronous buffer, wherein the processor is configured to read the ith sampled signal from the synchronous buffer and to multiple the ith sampled signal by a conjugate signal of the ith local linear frequency modulation signal to obtain a first product, the first product is subjected to first discrete fourier transform to obtain a first frequency modulation value and a first residual fractional frequency deviation, by the first frequency modulation value and a residual fractional frequency deviation accumulative value corresponding to ith sampled signal, the ith local linear frequency modulation signal is adjusted;
ith sampled signal is multiplied by the conjugate signal of the adjusted ith local linear frequency modulation signal to obtain a second product, the second product is subjected to second discrete fourier transform to obtain a second frequency modulation value and a second residual fractional frequency deviation;
the second residual fractional frequency deviation is added to the residual fractional frequency deviation accumulative value corresponding to the ith sampled signal to obtain a sum, and the sum is considered as a residual fractional frequency deviation accumulative value corresponding to the (i+1)th sampled signal;
the first frequency modulation value and the second frequency modulation value are output to an adder respectively;
1iN, N is the number of the sampled signal, and N is calculated as the quotient of the total length of the target linear frequency modulation signal and the preset length;
and
the adder, configured to add the first frequency modulation value and the second frequency modulation value to obtain a sum, wherein the sum is adopted as modulation information of the target linear frequency modulation signal.

192 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/423,433Filed 10 Oct 2020
Priority: CN 201910971545.X14 Oct 2019
Published: US 2022/0150095 A112 May 2022
Granted: 25 Apr 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04L 27/122
Modulator circuits; Transmitter circuits: using digital generation of carrier signals
H04L 12/16
Details: arrangements for providing special services to substations
H04L 27/148
With demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements: using…
Y02D 30/70
Reducing energy consumption in communication networks: in wireless communication networks