IP Library › Granted Patent US 10,715,304

Granted Patent B2

US 10,715,304 · App. 16/254,553 · Granted Jul 14, 2020

Modulation method and apparatus applicable to OvXDM system, and OvXDM system

Inventors: Ruopeng Liu (Guangdong, CN); Chunlin Ji (Guangdong, CN); XingAn Xu (Guangdong, CN); Shasha Zhang (Guangdong, CN)

Assignee: SHENZHEN SHEN ZHEN KUANG-SHI HEZHONG TECHNOLOGY LTD.

H04L5/22 H04L25/497 H04L27/00 H04L27/2602 H04L27/3405

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Quick Facts

Patent No.: US 10,715,304
App. No.: 16/254,553
Granted: Jul 14, 2020
Kind: B2

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USPTO Patent Center↗ Full Patent PDF↗

Abstract

The present invention discloses a modulation method and a modulation apparatus applicable to an OvXDM system, and an OvXDM system. On the one hand, an initial envelope waveform is virtually cut off, and a modulation-domain shift interval is calculated by using a virtual cutoff width of the initial envelope waveform, such that a symbol width obtained after modulation becomes smaller, and a transmission rate is improved; on the other hand, because the initial envelope waveform is virtually cut off but not really cut off, shifting and superimposition are still performed on an initial envelope waveform with tailing, such that the waveform still retains a good performance, such as a relatively narrow width and relatively fast side lobe attenuation, in a corresponding domain. Therefore, in the present invention, the good performance of the waveform is retained in the corresponding domain while the transmission rate is increased.

Claims (97)

1. A modulation method applicable to an Overlapped X Division Multiplexing (OvXDM) system, and comprising the following steps:

generating an initial envelope waveform in a modulation domain based on design parameters;

subtracting a tail length of the initial envelope waveform from a width of the initial envelope waveform in the modulation domain, to obtain a virtual cutoff width of the initial envelope waveform;

dividing the virtual cutoff width of the initial envelope waveform by a first quantity of times of overlapped multiplexing, to obtain a modulation-domain shift interval;

shifting the initial envelope waveform by the modulation-domain shift interval in the modulation domain based on the first quantity of times of overlapped multiplexing, to obtain offset envelope waveforms in the modulation domain;

multiplying symbols in a to-be-modulated sequence by the offset envelope waveforms that are respectively corresponding to the symbols, to obtain modulated envelope waveforms in the modulation domain; and

superimposing the modulated envelope waveforms in the modulation domain, to obtain a complex modulated envelope waveform in the modulation domain.

2. The modulation method applicable to an OvXDM system according to claim 1 , and further comprising a step of determining the tail length of the initial envelope waveform which includes the following steps:

converting an amplitude of the initial envelope waveform to a power in the modulation domain, comparing the power with a signal-to-noise ratio threshold of the system, and determining a modulation-domain part of the initial envelope waveform corresponding to the power that is smaller than the signal-to-noise ratio threshold as tailing.

3. The modulation method applicable to an OvXDM system according to claim 1 , wherein the OvXDM system is an Overlapped Frequency Division Multiplexing (OvFDM) system, an Overlapped Time Division Multiplexing (OvTDM) system, an Overlapped Hybrid Division Multiplexing (OvHDM) system, an Overlapped Code Division Multiplexing (OvCDM) system, or an Overlapped Space Division Multiplexing (OvSDM) system.

4. The modulation method applicable to an OvXDM system according to claim 3 , wherein the modulation domain is a frequency domain when the OvXDM system is the OvFDM system; or the modulation domain is a time domain when the OvXDM system is the OvTDM system.

5. The modulation method applicable to an OvXDM system according to claim 3 , wherein when the OvXDM system is the OvHDM system, the virtual cutoff modulating method further comprises the following steps:

obtaining a plurality of complex modulated envelope waveforms in the modulation domain, wherein the modulation domain is a time domain;

adding, based on a second quantity of times of overlapped multiplexing, the complex modulated envelope waveforms in the time domain to corresponding subcarriers, and performing shifting and overlapping operations on the subcarriers in a frequency domain, to obtain complex modulated envelope waveforms of the subcarriers; and

superimposing the complex modulated envelope waveforms of the subcarriers in the frequency domain, to obtain a time-frequency complex modulated envelope waveform.

6. The modulation method applicable to an OvXDM system according to claim 1 , wherein the initial envelope waveform is smooth in the modulation domain.

7. The modulation method applicable to an OvXDM system according to claim 6 , wherein the initial envelope waveform is:

an envelope waveform of a Parzen window function or an envelope waveform of a derived window function of the Parzen window function; or

an envelope waveform of a Bartlett window function or an envelope waveform of a derived window function of the Bartlett window function; or

an envelope waveform of a Bartlett-Hanning window function or an envelope waveform of a derived window function of the Bartlett-Hanning window function; or

an envelope waveform of a Bohman window function or an envelope waveform of a derived window function of the Bohman window function; or

an envelope waveform of a Blackman window function or an envelope waveform of a derived window function of the Blackman window function; or

an envelope waveform of a Blackman-Harris window function or an envelope waveform of a derived window function of the Blackman-Harris window function; or

an envelope waveform of a Gaussian window function or an envelope waveform of a derived window function of the Gaussian window function; or

an envelope waveform of a Hamming window function or an envelope waveform of a derived window function of the Hamming window function; or

an envelope waveform of a Hanning window function or an envelope waveform of a derived window function of the Hanning window function; or

an envelope waveform of a Kaiser window function or an envelope waveform of a derived window function of the Kaiser window function; or

an envelope waveform of a Nuttall window function or an envelope waveform of a derived window function of the Nuttall window function; or

an envelope waveform of a flat top window function or an envelope waveform of a derived window function of the flat top window function; or

an envelope waveform of a Chebyshev window function or an envelope waveform of a derived window function of the Chebyshev window function; or

an envelope waveform of a triangular window function or an envelope waveform of a derived window function of the triangular window function; or

an envelope waveform of a Taylor window function or an envelope waveform of a derived window function of the Taylor window function; or

an envelope waveform of a Tukey window function or an envelope waveform of a derived window function of the Tukey window function.

8. A modulation apparatus applicable to an Overlapped X Division Multiplexing (OvXDM) system, and comprising:

a hardware processor,

a waveform generation module, configured for generating an initial envelope waveform in a modulation domain based on design parameters;

a virtual cutoff module, which is a program module and is executed by the hardware processor to subtract a tail length of the initial envelope waveform from a width of the initial envelope waveform in the modulation domain, to obtain a virtual cutoff width of the initial envelope waveform;

a modulation-domain shift interval calculating module, which is a program module and is executed by the hardware processor to divide the virtual cutoff width of the initial envelope waveform by a first quantity of times of overlapped multiplexing, to obtain a modulation-domain shift interval;

a first shift module, configured for shifting the initial envelope waveform by the modulation-domain shift interval in the modulation domain based on the first quantity of times of overlapped multiplexing, to obtain offset envelope waveforms in the modulation domain;

a multiplication module, configured for multiplying symbols in a to-be-modulated sequence by the offset envelope waveforms that are respectively corresponding to the symbols, to obtain modulated envelope waveforms in the modulation domain; and

a first superimposition module, configured for superimposing the modulated envelope waveforms in the modulation domain, to obtain a complex modulated envelope waveform in the modulation domain.

9. The modulation apparatus applicable to an OvXDM system according to claim 8 , and further comprising a tailing determining module, which is a program module and is executed by the hardware processor to: convert an amplitude of the initial envelope waveform to a power in the modulation domain, compare the power with a signal-to-noise ratio threshold of the system, and determine a modulation-domain part of the initial envelope waveform corresponding to the power that is smaller than the signal-to-noise ratio threshold as tailing.

10. The modulation apparatus applicable to an OvXDM system according to claim 8 , wherein the modulation domain is a frequency domain when the OvXDM system is an Overlapped Frequency Division Multiplexing (OvFDM) system; or the modulation domain is a time domain when the OvXDM system is an Overlapped Time Division Multiplexing (OvTDM) system.

11. The modulation apparatus applicable to an OvXDM system according to claim 8 , wherein when the OvXDM system is an Overlapped Hybrid Division Multiplexing (OvHDM) system, the modulation apparatus further comprises:

a second shift module, configured for: adding, based on a second quantity of times of overlapped multiplexing, a plurality of complex modulated envelope waveforms in the time domain obtained by the first superimposition module to corresponding subcarriers, and perform shifting and overlapping operations on the subcarriers in the frequency domain, to obtain complex modulated envelope waveforms of the subcarriers; and

a second superimposition module, configured for superimposing the complex modulated envelope waveforms of the subcarriers in the frequency domain, to obtain a time-frequency complex modulated envelope waveform.

12. The modulation apparatus applicable to an OvXDM system according to claim 8 , wherein the initial envelope waveform generated by the waveform generation module is smooth in the modulation domain.

13. The modulation apparatus applicable to an OvXDM system according to claim 12 , wherein the initial envelope waveform generated by the waveform generation module is: