CN104980390B - A kind of demodulation method of diclinic rate combination chirp signals - Google Patents
A kind of demodulation method of diclinic rate combination chirp signals Download PDFInfo
- Publication number
- CN104980390B CN104980390B CN201510288953.7A CN201510288953A CN104980390B CN 104980390 B CN104980390 B CN 104980390B CN 201510288953 A CN201510288953 A CN 201510288953A CN 104980390 B CN104980390 B CN 104980390B
- Authority
- CN
- China
- Prior art keywords
- chirp signals
- slope
- formula
- combination
- mcr
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2649—Demodulators
- H04L27/265—Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators
Abstract
A kind of demodulation method of diclinic rate combination chirp signals, is related to water sound sensor network.Chirp signals are combined for diclinic rate, using mixing variable slope Fourier Transform of Fractional Order Parameter Estimation Method, in parameter Estimation flow, MCR FrFT are made up of mixing variable slope and Fourier Transform of Fractional Order.Using MCR FrFT, for the combination chirp signals of selection, to the estimation procedure of parameter in terms of operand than directly coming few using FrFT.For the different combination chirp signals of the absolute value of two slope over 10, need to realize the detection of parameter with two different p values, need FrFT computings twice, and combine chirp signals for the absolute value identical of two slope over 10, only need a p value to achieve that the parameter detecting of two segment signals, i.e., only need FrFT operands once.Compared to traditional directly Fourier Transform of Fractional Order method for parameter estimation, there is higher operation efficiency.
Description
Technical field
The present invention relates to water sound sensor network, more particularly, to a kind of demodulation method of diclinic rate combination chirp signals.
Background technology
Document [0,2,3,4,5] is from the aspect of solving the problems, such as signal conflict and improving multiple access access performance, by two sections of tools
The chirp signal groups for having different Chirp rates are used in combination, and we can send out in the result introduction and verification process from article
Existing, this method can greatly promote the multiple access performance of system and solve conflict avoidance.In document [5], author make use of chirp
The MDMA characteristics of signal, while amplitude modulation(PAM) is make use of to ensure the orthogonality between signal, further improve conflict avoidance and ask
Topic.In document [2], author employs a kind of combination chirp signals different from echo signal type to reach identical mesh
's.But these documents are read over, find not for the demodulation method of diclinic rate combination chirp signals, that is to say, that
A complete, effective demodulating system is not formed.
For single-slope chirp signals, more demodulation method there are.In document [6], when author utilizes corresponding
Extension signal carries out slope to this signal and handled, and obtains MFSK signals.Then using conventional MFSK signal demodulating methods come real
Existing original signal parameter Estimation.Simply easily realized for single-slope chirp signals this method, but for combination chirp signals and
Speech, this method is infeasible, because two slope values of combination chirp signals are different, can not form MFSK signals.
In document [3,7], author carries out correlation demodulation using matched filter method of reseptance to signal, and this method has very high solution
Adjust efficiency.But for combination chirp signals, it is necessary to which more matched filters, add equipment complexity, add system
Energy loss.In document [8,9,10], author is carried out using Fourier Transform of Fractional Order (FrFT) to single-slope chirp signals
Analysis, energy accumulation peak can be obtained for specific slope value under specific fractional order exponent number, can be obtained accordingly very well
Demodulation effect.Document [11,12] proposes EEMD-FrFT and STFT methods respectively in order to reduce traditional FrFT operand.
But it is inconvenient that these FrFT methods for being directed to single-slope chirp signals, which are directly used on combination chirp signals, because tiltedly
Rate value is doubled so operand can be brought to double.Based on the consideration in existing technology and detection device complexity and operand,
It is proposed that a kind of efficient combination chirp signal demodulating methods, are mixed variable slope Fourier Transform of Fractional Order method.
Bibliography：
1.Charu Gupta,Antonia Papandreou-Suppappola.Wireless CDMA
Communications Using Time-Varying Signals,International Symposium on Signal
Processing and Its Applications(ISSPA),Kuala Lumpur,Malaysia,13-16August,
2001.
2.Phichet Moungnoul,Tran Tuan Huang and Tawil Paungma.Investigation
of Multi-Linear Chirp FH-CDMA over Fading Channel Model.ICICS,2005.
3.Said E.EI-Khamy,Shawki E.Shaaban and Essam A.Thabet.Efficient
Multiple-Access Communications Using Multi-User Chirp Modulation Signals,in
Proceeding of the IEEE 4th International Symposium on Spread Spectrum
Techniques and Applications,1996.
4.Peng Zhang,Hao Liu and Jianhao Hu.A Novel Multiple-Access Scheme
for Chirp UWB.In Proceedings of IEEE Wireless Communications and Networking
Conference(WCNC),2007.
5.H.Shen,S.Machineni,C.Gupta and A.Papandreou-Suppappola.Tiem-Varying
Multichirp Rate Modulation for Multiple Access Systems.IEEE Signal Processing
Letters.11(5),2004.
6. king Katyuan, the Novel demodulation method of Chirp-rate modulation, Networks and Communications, vol.30, no.9,2011.
7.T.Leszczynski,“Matched Filtration of LFM Signals with Non-Zero
Initial Frequency,”ACTA PHYSICA POLONICA A,vol.124,no.3,pp.494-497,Sep 2013.
8.J.Song,Y.X.Wang and Y.F.Liu,“Iterative Interpolation for Parameter
Estimation of LFM Signal Based on Fractional Fourier Transform,”Circuits
Systems and Signal Processing,vol.32,pp.1489-1499,2013.
9.R.Chen and Y.M.Wang,“Universal FRFT-based Algorithm for Parameter
Estimation of Chirp Signals,”Journal of Systems Engineering and Electronics,
vol.23,no.4,pp.495-501,2012.
10.F.Liu,Y.Huang,R.Tao and Y.Wang,“Chirp-Rate Resolution of
Fractional Fourier Transform in Multi-component LFM Signal,”Journal of
Beijing Institute of Technology,vol.18,pp.74-78,2009.
11.H.Y.Hao,“Multi component LFM signal detection and parameter
estimation based on EEMD-FRFT,”OPTIK,vol.124,no.23,pp.6093-6096,2013.
12.L.R.Shen,Q.B.Yin and M.Y.Lu,“Linear FM Signal Parameter Estimation
Using STFT and FRFT,”CHINESE JOURNAL OF ELECTRONICS,vol.22,pp.301-307,2013.
The content of the invention
It is an object of the invention to provide a kind of demodulation method of diclinic rate combination chirp signals.
The present invention is for diclinic rate combination chirp signals, using mixing variable slope Fourier Transform of Fractional Order parameter Estimation
Method, in the parameter Estimation flow of this method, MCR-FrFT is by mixing variable slope (MCR) and Fourier Transform of Fractional Order (FrFT) two
Part forms.
For combining chirp signals, it is assumed that its slope is combined as：
Wherein, M represents the sum of combination chirp signals, and m represents m-th of combination chirp signal, μmfRepresent combination chirp
The first half slope value of signal, μmbIt is the combination latter part of slope value of chirp signals, T and B are combination chirp letters respectively
Number duration and bandwidth, then corresponding signal can be expressed as：
Wherein, f0Represent carrier frequency.
A.MCR is made up of multiplier and low pass filter.
If local signal xlocal (t) expression formula is formula (2)：
First expression formula is corresponding with MCR in tie point in formula (2), and in formula (2) second expression formula be with
3rd branch road MCR is corresponding, is multiplied when combining chirp signals with local signal xlocal (t), according to product to sum formula and low pass
The MCR results such as formula (3) that the function (filtering out high frequency item) of wave filter obtains：
Chirp signals for possessing positive slope combination, the signal after MCR is converted is in the time existing for the 3rd branch road
Length is also insufficient compared to tie pointAs formula (4) (calculates) according to relationship between frequency and time；Similarly, for possessing negative slope combination
Chirp signals, the signal after MCR is converted is also insufficient compared to tie point in time span existing for tie point
Article 2 branch road is existing according to M odd even, and slope situation is corresponding to MCR result：
When M is odd number
When M is even number
Formula (5), (6) illustrate when M is even number, in the absence of the signal that slope is 0, it is possible to saves in detection block diagram the
The related operation of two branch roads, but when M is odd number, just must take into consideration the presence of the second branch road.
B. parameter Estimation Part II is Fourier Transform of Fractional Order.
Multiple conversion exponent number p, p value are according to corresponding to directly storing the different slope value of multiple signals
When energy accumulating peak point occurs in r (t) p ranks DFrFT, then the positional information m of peak point is further determined that0
WhenWhen, obtain formula (7)：
WhenWhen, obtain formula (8)：
Wherein, B=k0T, p0To there is the exponent number p that obvious energy accumulating peak is, so can be right by formula (7) or formula (8)
The slope value of signal, positional information m should be gone out0It is formula (9) with the relational expression of centre frequency and the anglec of rotation
m0=Δ xfi·S·sin(α0)+N/2 (9)
Wherein, fiCentered on frequency,For bearing length,For yardstick because
Son, α0It is and p0The corresponding anglec of rotation, N are sampling numbers；In the way of poll, (energy can occur to gather in optimal p value
The position of the peak value, and then the other parameters such as slope value and centre frequency corresponding to determination are obtained under Ji Feng).
The present invention utilizes MCR-FrFT, for the combination chirp signals of selection, to the estimation procedure of parameter in computing
Than directly coming few using FrFT in terms of amount.For the different combination chirp signals of the absolute value of two slope over 10, it is necessary to use two
Different p values realizes the detection of parameter, that is, needs FrFT computings twice, and is combined for the absolute value identical of two slope over 10
Chirp signals, it is only necessary to which a p value can realizes the parameter detecting of two segment signals, i.e., only needs FrFT operands once.
The present invention mainly considers from demodulation angle, proposes the demodulation method of a kind of combination chirp signals, can be different by such
Combination chirp signal distinguishings come.Chirp signals are because have good noise robustness and the influence to Doppler frequency shift
There is natural immunity and be widely used in subsurface communication.And in water sound sensor network, because to ensure to use
Fairness between family is, it is necessary to have identical time-bandwidth product, so diclinic rate combination chirp letters between ensureing each user
Number become a kind of typical selection.But in many visible documents, diclinic rate is combined chirp signals propose compared with
Good feasible demodulation method.In order to realize efficient demodulation (the mainly slope value and center frequency to such combination chirp signal
The estimation of rate value), it is mixed we have proposed one kind and becomes diagonal fraction rank Fourier transformation method.The present invention is a kind of combined method,
It is made up of two parts.The first step is that mixing is gone tiltedly, and two different slope values that diclinic rate is combined to chirp signals are changed into two
The new combination chirp signals of slope value opposite number each other, then estimate this using discrete Fourier Transform of Fractional Order method
The parameter of signal.The present invention has higher computing compared to traditional direct Fourier Transform of Fractional Order method for parameter estimation
Efficiency.
Brief description of the drawings
Fig. 1 is the relationship between frequency and time figure that diclinic rate combines chirp signals.
Fig. 2 is the parametric demodulation block diagram of the embodiment of the present invention.
Fig. 3 is the MCR block diagrams of the embodiment of the present invention.
Embodiment
Following examples will the present invention is further illustrated with reference to accompanying drawing.
Echo signal type：The present invention is for diclinic rate combination chirp signals as shown in Figure 1.
Fig. 1 is the relationship between frequency and time figure of diclinic rate combination chirp signals.From this figure it can be seen that such combination chirp signal
The characteristics of have：
1st, all signals have identical time-bandwidth product, D=BT, wherein B representation signals bandwidth, T representation signals
Duration；
2nd, slope value bePlace changes；
3rd, between adjacent signalsThe frequency-splitting at place is identical, isWherein M represents such signal
Number.
For combination chirp signals, it is proposed that mixing variable slope Fourier Transform of Fractional Order Parameter Estimation Method.This method
Parameter Estimation flow it is for example as shown in Figure 2.As seen from Figure 2, MCR-FrFT is mainly made up of two parts, and Part I is
MCR, variable slope is referred to as mixed, Part II is FrFT, referred to as Fourier Transform of Fractional Order.
Below, specific parameter Estimation is illustrated：For combining chirp signals, it is assumed that its slope is combined asWherein, M represents the sum of combination chirp signals, and m represents m-th group
Close chirp signals, μmfRepresent the first half slope value of combination chirp signals, μmbIt is that combination chirp signals are latter part of
Slope value.T and B is duration and the bandwidth for combining chirp signals respectively.Then corresponding signal can be expressed as：
f0Represent carrier frequency.
A.MCR is made up of multiplier and low pass filter, and its internal frame diagram is as shown in Figure 3.
If local signal xlocal (t) expression formula is formula (2)
First expression formula is corresponding with MCR in the tie point in Fig. 2 in formula (2), and second expression in formula (2)
Formula is corresponding with the 3rd branch road MCR in Fig. 2.It is multiplied when combining chirp signals with local signal xlocal (t), according to productization
The MCR results such as formula (3) obtained with the function of poor formula and low pass filter (filtering out high frequency item)：
Chirp signals for possessing positive slope combination, the signal after MCR is converted is in the time existing for the 3rd branch road
Length is also insufficient compared to tie pointAs formula (4) (calculates) according to relationship between frequency and time.Similarly, for possessing negative slope combination
Chirp signals, the signal after MCR is converted is also insufficient compared to tie point in time span existing for tie point
So for the 3rd branch road, it is negligible to be disturbed caused by positive slope combination chirp signals,
It is also negligible that similarly negative slope, which combines the caused interference in tie point of chirp signals,.
In fig. 2, it also there are Article 2 branch road.This branch road is mainly existing according to M odd even.So MCR
Result corresponding to slope situation be：
When M is odd number
When M is even number
Formula (5), (6) illustrate when M is even number, in the absence of the signal that slope is 0, it is possible to saves in detection block diagram the
The related operation of two branch roads, but when M is odd number, we just must take into consideration the presence of the second branch road.Simultaneously from two formulas above
We can be clearly seen that, the combination chirp signals of the type become the new of two slopes opposite number each other after MCR
Combine chirp signals.The advantage brought on this result we analyzed below.
B. the Part II of parameter Estimation block diagram is Fourier Transform of Fractional Order.On Fourier Transform of Fractional Order and discrete
We can see introduction to Fourier Transform of Fractional Order on many reference books, here just without repeating.The difference is that we
Here multiple conversion exponent number p, p not by the way of search but according to corresponding to directly storing the different slope value of multiple signals
Value be
The positional information m of peak point is then further determined that when energy accumulating peak point occurs in r (t) p ranks DFrFT0
WhenWhen obtain formula (7)
WhenWhen, obtain formula (8)
Wherein, B=k0T, p0To there is the exponent number p that obvious energy accumulating peak is.So it can be corresponded to out by (7) or (8)
The slope value of signal.Positional information m0It is (9) with the relational expression of centre frequency and the anglec of rotation
m0=Δ xfi·S·sin(α0)+N/2 (9)
Wherein fiCentered on frequency,For bearing length,For yardstick because
Son, α0It is and p0The corresponding anglec of rotation, N are sampling numbers.So, in the way of poll, we (can go out in optimal p value
Existing energy accumulating peak) under obtain the position of the peak value, and then other parameters such as slope value and centre frequency corresponding to determining.
Using MCR-FrFT, for the combination chirp signals of selection, to the estimation procedure of parameter in terms of operand
Than directly coming few using FrFT.It is for the different combination chirp signals of the absolute value of two slope over 10, it is necessary to different with two
P value realizes the detection of parameter, that is, needs FrFT computings twice, and combines chirp for the absolute value identical of two slope over 10
Signal, it is only necessary to which a p value can realizes the parameter detecting of two segment signals, i.e., only needs FrFT operands once.
So of the invention mainly consider from demodulation angle, to propose the demodulation method of a kind of combination chirp signals, energy should
The different combination chirp signal distinguishings of class come.Chirp signals are because with good noise robustness and to Doppler frequency shift
Influence have natural immunity and be widely used in subsurface communication.And in water sound sensor network, because will
Ensure the fairness between user, it is necessary to have identical time-bandwidth product between ensureing each user, so diclinic rate combines
Chirp signals become a kind of typical selection.But in many visible documents, not to diclinic rate combination chirp letters
Number propose preferably feasible demodulation method.In order to realize efficient demodulation (the mainly slope value to such combination chirp signal
With the estimation of center frequency value), it is mixed we have proposed one kind and becomes diagonal fraction rank Fourier transformation method.This method is a kind of group
Conjunction method, is made up of two parts.The first step is that mixing goes that diclinic rate is tiltedly combined to two different slope values of chirp signals
It is changed into the new combination chirp signals of two slope values opposite number each other, then utilizes discrete Fourier Transform of Fractional Order method
To estimate the parameter of the signal.The present invention has more compared to traditional direct Fourier Transform of Fractional Order method for parameter estimation
High operation efficiency.
Claims (1)
1. a kind of demodulation method of diclinic rate combination chirp signals, it is characterised in that combine chirp signals for diclinic rate, adopt
With mixing variable slope Fourier Transform of Fractional Order Parameter Estimation Method, in parameter Estimation flow, MCR-FrFT is by mixing variable slope MCR
Formed with Fourier Transform of Fractional Order FrFT two parts；
For combining chirp signals, it is assumed that its slope is combined as：
Wherein, M represents the sum of combination chirp signals, and m represents m-th of combination chirp signal, μmfRepresent combination chirp signals
First half slope value, μmbIt is the combination latter part of slope value of chirp signals, T and B are combination chirp signals respectively
Duration and bandwidth, then corresponding signal be expressed as：
Wherein, f0Represent carrier frequency；
A.MCR is made up of multiplier and low pass filter；
If local signal xlocal (t) expression formula is formula (2)：
First expression formula is corresponding with MCR in tie point in formula (2), and second expression formula is and the 3rd in formula (2)
Branch road MCR is corresponding, is multiplied when combining chirp signals with local signal xlocal (t), according to product to sum formula and LPF
The function of device, obtained MCR results such as formula (3)：
Chirp signals for possessing positive slope combination, the signal after MCR is converted is in time span existing for the 3rd branch road
It is also insufficient compared to tie pointSuch as formula (4)；Similarly, the chirp signals combined for possessing negative slope, are converted by MCR
Signal afterwards is also insufficient compared to tie point in time span existing for tie point
Article 2 branch road is existing according to M odd even, and slope situation is corresponding to MCR result：
When M is odd number
When M is even number
Formula (5), (6) illustrate when M is even number, in the absence of the signal that slope is 0, save the correlation for detecting the second branch road in block diagram
Computing, but when M is odd number, just must take into consideration the presence of the second branch road；
B. parameter Estimation Part II is Fourier Transform of Fractional Order：
Multiple conversion exponent number p, p value are according to corresponding to directly storing the different slope value of multiple signals
When energy accumulating peak point occurs in r (t) p ranks DFrFT, then the positional information m of peak point is further determined that0；
WhenWhen, obtain formula (7)：
WhenWhen, obtain formula (8)：
Wherein, B=k0T, p0Exponent number p during energy accumulating peak occur, correspond to the slope of signal by formula (7) or formula (8)
Value, positional information m0It is formula (9) with the relational expression of centre frequency and the anglec of rotation：
m0=Δ xfi·S·sin(α0)+N/2 (9)
Wherein, fiCentered on frequency,For bearing length,For scale factor, α0
It is and p0The corresponding anglec of rotation, N are sampling numbers；In the way of poll, the position of the peak value is obtained under optimal p value,
And then slope value and centre frequency other parameters corresponding to determining.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510288953.7A CN104980390B (en) | 2015-05-31 | 2015-05-31 | A kind of demodulation method of diclinic rate combination chirp signals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510288953.7A CN104980390B (en) | 2015-05-31 | 2015-05-31 | A kind of demodulation method of diclinic rate combination chirp signals |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104980390A CN104980390A (en) | 2015-10-14 |
| CN104980390B true CN104980390B (en) | 2018-01-09 |
Family
ID=54276501
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510288953.7A Active CN104980390B (en) | 2015-05-31 | 2015-05-31 | A kind of demodulation method of diclinic rate combination chirp signals |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104980390B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105919624B (en) * | 2016-05-25 | 2019-09-10 | 飞依诺科技(苏州)有限公司 | A kind of high impulse repeats the coding and device of scanning frequency signal |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101388877A (en) * | 2008-11-05 | 2009-03-18 | 北京理工大学 | Chirp spread spectrum technique non-coherent demodulation method based on fractional Fourier transform |
| CN103424754A (en) * | 2013-07-18 | 2013-12-04 | 哈尔滨工程大学 | Multiplex binary offset carrier (MBOC) modulating signal fuzzy-free multi-path restraining method based on correlation function synthesis |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060160516A1 (en) * | 2005-01-14 | 2006-07-20 | Dongsong Zeng | Pulse shaping optimizer in UWB receiver |
-
2015
- 2015-05-31 CN CN201510288953.7A patent/CN104980390B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101388877A (en) * | 2008-11-05 | 2009-03-18 | 北京理工大学 | Chirp spread spectrum technique non-coherent demodulation method based on fractional Fourier transform |
| CN103424754A (en) * | 2013-07-18 | 2013-12-04 | 哈尔滨工程大学 | Multiplex binary offset carrier (MBOC) modulating signal fuzzy-free multi-path restraining method based on correlation function synthesis |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104980390A (en) | 2015-10-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ren et al. | A chaotic spread spectrum system for underwater acoustic communication | |
| CN111711589B (en) | Continuous phase modulation and demodulation method based on elliptical spherical wave signal | |
| CN111935046B (en) | Low-complexity frequency shift keying signal symbol rate estimation method | |
| CN106209701B (en) | MFSK signal code rate-estimation method and device under Alpha Stable distritation noise circumstance | |
| CN109286457B (en) | TWACS uplink signal detection method based on wavelet analysis | |
| CN111711590A (en) | Multi-branch continuous phase modulation and demodulation method based on elliptical spherical wave signals | |
| CN106027432B (en) | A kind of CPFSK bit rate estimation method based on signal transient frequency-portions correlation function | |
| CN114884534B (en) | LoRa-based dual-carrier ramp keying modulation and demodulation method and device | |
| Kim et al. | Chirp spread spectrum transceiver design and implementation for real time locating system | |
| CN104980390B (en) | A kind of demodulation method of diclinic rate combination chirp signals | |
| Singh et al. | Advanced multiresolution wavelet based wideband spectrum sensing technique for cognitive radio | |
| CN102843165B (en) | Nonlinear signal processing device used for pulse ultra wideband system | |
| CN105406921A (en) | MFSK water sound communication method and MFSK water sound communication system | |
| Qiu et al. | Parameter estimation of frequency shift keying radar signal intercepted by Nyquist folding receiver using periodic linear frequency modulation local oscillator | |
| Cai et al. | Single channel steepest descent algorithm for the correction of cycle frequency error | |
| Fu et al. | The DPSK signal noncoherent demodulation receiver based on the Duffing oscillators array | |
| CN103856972B (en) | Broader frequency spectrum cognitive method and device and corresponding user equipment and base station | |
| Kim et al. | Selective discrete wavelet packet trnasform-based energy detector for cognitive radios | |
| Guan et al. | Intelligent recognition of subcarrier for wireless link of satellite communication | |
| Salman et al. | A performance analysis of a new periodogram for spectrum sensing | |
| CN113904703B (en) | Continuous spectrum random signal carrier communication method | |
| JPH08204766A (en) | Frequency analysis detection system for time limit waveform | |
| Narendar et al. | A tree-structured DFT filter bank based spectrum detector for estimation of radio channel edge frequencies in cognitive radios | |
| Kobayashi et al. | Improved MB Cognitive Radio Spectrum Sensing Using Wavelet Spectrum Filtering | |
| Abeysekera | Efficient estimation of a sequence of frequencies for M-ary CPFSK demodulation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |