AU2018451596B2 - 5G multi-carrier spread spectrum underwater acoustic communication method - Google Patents
5G multi-carrier spread spectrum underwater acoustic communication method Download PDFInfo
- Publication number
- AU2018451596B2 AU2018451596B2 AU2018451596A AU2018451596A AU2018451596B2 AU 2018451596 B2 AU2018451596 B2 AU 2018451596B2 AU 2018451596 A AU2018451596 A AU 2018451596A AU 2018451596 A AU2018451596 A AU 2018451596A AU 2018451596 B2 AU2018451596 B2 AU 2018451596B2
- Authority
- AU
- Australia
- Prior art keywords
- spread spectrum
- data
- underwater acoustic
- gfdm
- expressed
- 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
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/707—Spread spectrum techniques using direct sequence modulation
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
The present invention relates to a 5G multi-carrier spread spectrum underwater acoustic communication method, belongs to the field of underwater acoustic communication, and relates to generalized frequency division multiplexing (GFDM) underwater acoustic communication technology and spread spectrum underwater acoustic communication technology. A GFDM spread spectrum underwater acoustic communication system suitable for use in the underwater acoustic field provided by the present invention implements effective information transmission in an underwater acoustic channel of limited bandwidth resources. The present invention aims to provide an effective information transmission method for the field of underwater acoustic communication of limited channel bandwidth resources, and the method has important significance for development of underwater acoustic technology.
Description
5G MULTI-CARRIER SPREAD SPECTRUM UNDERWATER ACOUSTIC COMMUNICATION METHOD
The present invention relates to a 5G multi-carrier spread spectrum underwater acoustic communication method, belongs to the field of underwater acoustic communications, and relates to a Generalized Frequency Division Multiplexing (GFDM) underwater acoustic communication technology and a spread spectrum underwater acoustic communication technology.
In radio 5G, the main requirements for communication systems are high network capacity, low cost, and high data transmission rate, and such a high data transmission rate is not only a requirement in radio but also a requirement in high-speed underwater acoustic communications. The key technologies in 5G comprise several aspects such as realization of a large-scale Multiple Input Multiple Output (MIMO) system, an advanced multiple access technology, a full duplex technology, an new multi-carrier technology and an adaptive coding and modulation technology. As a result of such a rapid increase in user demand, the requirement of non-strict synchronization between users among multiple application scenarios, and the requirement of improving devices' processing capabilities, orthogonal multiple access technologies in traditional mobile communication technologies, e.g., a Frequency Division Multiple Access (FDMA) technology, a Time Division Multiple Access (TDMA) technology, a Code Division Multiple Access (CDMA) technology, and an Orthogonal Frequency Division Multiple Access (OFDMA) technology, evolve towards new technologies and new directions. In non-orthogonal transmission technologies, non-orthogonal multiple access technologies and multi-carrier technologies are two main technologies currently developed, in which non-orthogonal multiple access technologies are represented by Pattern Division Multiple Access (PDMA) technologies, and can be divided into several division modes, power domain division, generalized domain division and coding domain division. These emerging multi-carrier technologies have the advantage of high data transmission rate of traditional multi-carrier technologies, and are more flexible and effective than traditional multi-carrier technologies. However, the structure of GFDM based on a filter bank makes its channel estimation a difficult problem, at present there is no relevant literature that effectively solves this problem yet, and in underwater acoustic communications, the influence of an underwater acoustic channel on a communication system cannot be ignored; this disadvantage is the key point that hinders its application in the field of underwater acoustic communications. In view of the above problem, there is proposed herein a multi-carrier spread spectrum underwater acoustic communication technology. The advantages of spread spectrum technologies are used to make up for problems such as channel multi-path time delay.
An aspect of the present invention is to provide an efficient underwater acoustic communication solution for the field of underwater acoustic communications with limited channel bandwidth resources. The present invention proposes a GFDM spread spectrum underwater acoustic communication system suitable for the field of underwater acoustics, which realizes effective information transmission in an underwater acoustic channel with limited bandwidth resources. The aspect of the present invention is to provide an effective information transmission method for the field of underwater acoustic communications with limited channel bandwidth resources, which is of great significance for the development of underwater acoustic technologies. The aspect of the present invention is achieved by a method comprising the following steps: step 1: at a transmitting end, encoding source data, and performing a spread spectrum operation on the encoded serial data by using a spread spectrum sequence; step 2: performing GFDM modulation on data after spread spectrum, and after that, adding a cyclic prefix to the modulated data to obtain data for transmission; step 3: at a receiving end, performing synchronization and GFDM demodulation on the data, after the modulated signals pass through an underwater acoustic channel; and step 4: despreading the demodulated data, and integrating the obtained signals over a duration and making a judgement to obtain data estimated by the receiving end. wherein a spread spectrum process in the step 1 is as below: the encoded source data is expressed by d(t ), the spread spectrum sequence is expressed by c(t) and then the process can be expressed as: d(t)= d(n)g(t-nT,) c(t)= c(n)p(t-nT) where values of d(n) and a pseudo-random sequence c(n) used for spreading spectrum are 1 or -1, g(t) and p(t) are rectangular pulses of a unit amplitude with durations T and T:, respectively, N represents a length of the spread spectrum sequence, and in general, T,=NT; a sequence after spread spectrum p(t) is: p(t)= d(t)c(t) wherein Table 1 gives responses in a frequency domain of several typical g(t) filters: Table 1 Responses in a frequency domain of several typical filters Name Response in a frequency domain
RC (Raised Cosine filter) GRC[f]-rICos infl 2
RRC (Root-Raised Cosine filter) GRRC[f]= GRC[f]
where a represents a roll-off factor ln (x)= min 1, max 0, 2a a))
+ and a modulation process in the step 2 is expressed as below:
data after GFDM modulation is y(t) , g[-] is used to express a GFDM
modulation process, and then:
y(t)=g[p(t )]= g[d(t)c(t)]
a discrete spread spectrum signal for GFDM adopting a BPSK modulation mode can be expressed as: Ne -1 M GD
SMC-DS (t ) =EEE dk[i]cj]p, (-iT - jT)cos[2r(f0 +kAf')t] k=0 i=-M j=0
where dk[i] is data on a k-th subcarrier, ck[j] represents a spread spectrum
sequence which is correspondingly multiplied by d[i], Nc represents a number of
subcarriers,and Af'=1/T is a subcarrier spacing.
Preferably, the present invention further comprises any one or more features selected from the following items 3-4. 3. A process of performing the GFDM demodulation on the received signal in the step 3 is as below: at the receiving end, on the premise of correct synchronization, the GFDM
demodulation is performed on the received signal y(t), g-'[.] is used to represent the
GFDM demodulation process, and then a signal r(t) to be despread can be expressed
as:
r(t)=g-[y'(t)] 4. A process of despreading the received signal in the step 4 is as below: r(t) is despread by utilizing a spread spectrum sequence Cr(t) which is
generated locally and the same as that at the transmitting end:
M(t)=r(t)c,(t)=g-'[['(t]c,(t =g '[g[d(t)c(t)]]c, (t)=d(t)c(t)c,(t)
the signal is integrated over the duration:
q(t) = fm(t)dt where a pulse duration of the spread spectrum sequence c(t) is T, namely
Jb c(t)c,(t)dt = T
and therefore, q(t) can be expressed as:
f T, when d()=1 q(t) =
[-T when d(t=-I
5. Analysis of a bit error rate in the step 4 Each sub-block of GFDM is the same as to the number of sub-carriers therein, and thus it has the same bit error performance. With a chaotic spread spectrum sequence taken as an example to analyze the bit error rate performance, since a chaotic sequence has very strong autocorrelation and different chaotic sequences are mutually independent, there is E[RR,]=0 between different chaotic sequences;
besides, although a chaotic sequence has the characteristic of being noise-like, it is also independent of Gaussian white noise, and a chaotic sequence's mean value is 0, with a variance of 1.
for the demodulated signal d,,k at the receiving end, an information
sequence corresponding to it is represented by Sk, and the corresponding chaotic
sequence is represented by CM,
S. =([dic,+no, d c1+ n,---, dk c,_-,+n,_-, =d L/kG +w +
C"=[c, +n;, c + ni,---..c,,+ng =G +w2
where ni and ni are mutually independent Gaussian white noises, and they
are noises at the i-th data after spread spectrum in the received signal d,,k and at
the spread spectrum code, respectively, wi and w 2 represent sets of the two
noises, andG[Crc c,_Jis a set of the spread spectrum sequences;
information on the k-th subcarrier and the m-th subsymbol is expressed by
I = s x C,,, and then the mean value and the variance are, respectively:
E[l",/d =+1]=E[(Gk+w)(G.,,+w2 =E[G, +wG.,k+w 2 G.,k+wW2
as noise's mean value is 0, with a variance of 1, the above equation can be simplified as
E (l", / d", =+1]=E [G, 2Ec" = K -1 Eh K
for the same reason, the variance is:
Var /1,/d"n=+1]=E G +W 1 )2(Gf +W2)2 -E2 [(G, +WI)(G.,k +W2)]
=E[G +w+2+ w +2(w2)Gw
-E 2[Gk +WlG.,k+w2 Gm,,k+ wiw2
K-IEhN+ 2 ON2 K 4
since the structure of each subblock of GFDM is the same, its bit error rate
can be obtained based on the mean value and the variance:
BER = Pr(lj<O/di =+)+ Pr(l >O/dk =-I)
K-1 E 1 -erfc E~i, /dA=+1] 1 =-erfc K~l K E 2 ~ 2ar~l(Ik/di =+1 2 2 EbN N+ 2 j K 2,
= erfc 2V K
[ ( K -1/2N K __)
2y(K-1) K-1) 272 j
2 where erfc is an error function, erfc(x)= =h e-"dp , and 7 is a
signal-to-noise ratio.
A GFDM spread spectrum communication system performs GFDM modulation on N parallel signals on which spread spectrum has been performed, and in general, a number of parallel data is less than a number of subcarriers in an OFDM system. The GFDM-DS system transmits, in parallel, multiple data after direct spread spectrum, in underwater acoustic communications, the spread spectrum signals are limited by a bandwidth, and when the spread spectrum codes are relatively long, transmitting the signals and performing synchronization at the receiving end both require to take a lot of time. As compared with the prior art, the present invention has the following beneficial effects: realizing a GFDM spread spectrum underwater acoustic communication system for the first time, and verifying the system's performance through simulation and experimentation -- in experiments, a 5G multi-carrier spread spectrum underwater acoustic communication system based on a modulator structure of M=2 and K=29 achieved a bit error rate of 0.0119, and a 5G multi-carrier spread spectrum underwater acoustic communication system based on a modulator structure of M=29 and K=2 achieved error-free information transmission, which proves that the GFDM spread spectrum underwater acoustic communication system is a fire-new and efficient underwater acoustic communication system that can flexibly utilize a bandwidth of a transmission channel.
Figure 1: a schematic diagram of anti-interference of a spread spectrum system; Figure 2: a schematic diagram of multi-carrier time-domain spread spectrum; Figure 3: a schematic diagram of multi-carrier frequency-domain spread spectrum; Figure 4: (a) a schematic diagram of a transmitting end of a GFDM spread spectrum underwater acoustic system, and (b) a schematic diagram of a receiving end of the GFDM spread spectrum underwater acoustic system; Figure 5: a comparison diagram of bit error rate performance of GFDM spread spectrum underwater acoustic communication systems with different filter banks and different modulation matrices; Figure 6: an impulse response of an experimental channel; and Figure 7: pictures of transmission and reception in an experiment: (a) a transmitted image, (b) a received image of a GFDM spread spectrum underwater acoustic communication system (M=2, and K=29), and (c) a received image of a GFDM spread spectrum underwater acoustic communication system (M=29, and K=2).
A spread spectrum communication technology is that, at a transmitting end, a spread spectrum sequence is utilized to perform spread spectrum processing on a transmitted signal to spread an original bandwidth occupied by the signal, and at a receiving end, despread processing is performed on the transmitted signal by adopting a correlation inspection method, with a noise signal in the transmission process being spread into a broadband signal; the principle and process of anti-multipath interference thereof are shown in Figure 1. The target signal can be extracted by a narrowband filtering method. Since an interference signal has no coherence, it causes little interference to the useful signal, and there is relatively high signal-to-noise ratio. Due to the correlation detection performed at the receiving end, even if the same type of signal is used for interference, it is difficult for the interference to work relatively greatly as the code pattern of a pseudo-random sequence cannot be accurately obtained, and thus the system's anti-interference performance is effectively improved, which in turn reduces the system's bit error rate. Time-domain spread spectrum: a block diagram of multi-carrier time-domain spread spectrum transmission is as shown in Figure 2. At a transmitting end, serial-to-parallel conversion is performed on a data signal, after that, spread spectrum codes distributed in a time domain are utilized to perform a spread spectrum operation on each data symbol individually, and finally each data after spread spectrum is modulated by using a subcarrier of a different frequency, and ultimately multi-carrier time-domain spread spectrum is realized. It can be seen from the figure that all chips of each transmitted data after time-domain spread spectrum are transmitted on one subcarrier, which indicates that the system has a relatively poor ability to resist frequency-selective fading, while a length of the chips of each transmitted data after time-domain spread spectrum is the same as a length of the spread spectrum codes, and therefore the system has a relatively strong ability to resist time-selective fading. A schematic diagram of multi-carrier frequency-domain spread spectrum is as shown in Figure 3: transmitted data symbols are spread respectively using spreading codes distributed in a frequency domain. After spread spectrum, for each data symbol, L chips are obtained, and these L chips are modulated respectively on subcarriers whose number is the same as the number of the chips. In this spread spectrum mode, in a time domain, a duration of the transmitted data and a duration of the OFDM symbol are the same. In this section, a communication system based on multi-carrier time-domain spread spectrum is studied with respect to a multi-carrier system. A GFDM-DS system performs GFDM modulation on N parallel signals on which spread spectrum has been performed, and in general, a number of parallel data is less than a number of subcarriers in an OFDM system. The GFDM-DS system transmits, in parallel, multiple data after direct spread spectrum, in underwater acoustic communications, the spread spectrum signals are limited by a bandwidth, and when the spread spectrum codes are relatively long, transmitting the signals and performing synchronization at the receiving end both require to take a lot of time, and the receiving end of the GFDM-DS spread spectrum system adopts the method introduced above, as shown in Figure 4 (b). Figure 5 shows BER performance of RC and RRC filter banks with different modulation matrices in the case of Gaussian white noise and in a multipath channel, wherein two selected modulation matrices are as below: a number of subblocks M=2 and a number of subcarriers K=29; and, a number of subblocks M=29, and a number of subcarriers K=2. It can be seen from the figure that the bit error rate performance in the case of the number of subcarriers K=2 is significantly better than that of the modulation matrix with the number of subcarriers K=29, whether it is in the Gaussian white noise channel or the multipath channel. The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. An experiment was performed in an anechoic pool in May 2017, the pool having a length of 25 meters, a width of 15 meters, and a height of 10 meters, anechoic wedges being arranged around the pool. A transmitting transducer, having a working frequency band of 3-8kHz, was deployed at a depth of 3 meters, a standard hydrophone was adopted as a receiving hydrophone, which was deployed at a depth of 3 meters, and a horizontal distance between the transmitting transducer and the receiving hydrophone was 5 meters. The actually measured impulse response of a channel was as shown in Figure 6, maximum multipath time delay being about 5.5ms, a sampling frequency being 48kHz, and a situation of roll-off parameter(s) in two types of spread spectrum systems in which a RC filter is combined with a RRC filter bank being taken as an example to perform a comparison of experimental results. Transmission and reception of the GFDM-DS and GFDM-CSS spread spectrum underwater acoustic communication systems are performed by adopting the RC filter and the RRC filter bank. The present invention comprises the following steps: step 1: at a transmitting end, encoding binary source data, and performing a spread spectrum operation on the encoded serial data by using a spread spectrum sequence,
Figure 4 (a) is a principle diagram of a transmitting end and a receiving end for
spreading spectrum and despreading of a GFDM spread spectrum system, in which time-domain spread spectrum is performed on data undergoing parallel-to-serial conversion by using the spread spectrum sequence, after that, GFDM modulation is performed according to a GFDM modulation method to obtain modulated data, and a cyclic prefix is added to obtain transmitted data. At the receiving end, the received signals are synchronized firstly, on the premise of ensuring correct synchronization, the synchronized signals are demodulated and despread, and after that, the obtained signals are integrated over a duration and judged to obtain data estimated by the
receiving end, where the transmitted data is expressed by d(t ), and then a spread
spectrum process can be expressed as below:
d(t)= d(n)g(t-nT,)
c(t)= c(n)p(t-nT)
where, values of d(n) and a pseudo-random sequence c(n) used for
spreading spectrum are 1 or -1, g(t) and p(t) are rectangular pulses of a unit
amplitude with durations TI and Tc, respectively, N represents a length of the spread
spectrum sequence, in general, T=NTc, and a sequence after spread spectrum p(t)
is:
p(t) = d(t)c(t).
step 2: performing GFDM modulation on data after spread spectrum, and after that, adding a cyclic prefix to the modulated data to obtain transmitted data, wherein a modulation process can be expressed as below:
data after GFDM modulation is y(t) , g[-] is used to express a GFDM
modulation process, and then:
y(t)=g[p(t)] = g[d(t)c(t)]
and a discrete spread spectrum signal for GFDM adopting a BPSK modulation mode can be expressed as:
Sdk[i]ckp(t-iTI, -jT)cos[21r(fO +kAf')t] k=0 i=-M 1=0
where d[i] is data on a k-th subcarrier, Ck[j] represents a spread spectrum
sequence which is correspondingly multiplied by d[i], Nc represents a number of
subcarriers,and Af'=1/T is a subcarrier spacing.
step 3: at a receiving end, performing synchronization and GFDM demodulation on the data, after the modulated signals pass through an underwater acoustic channel; at the receiving end, on the premise of correct synchronization, the GFDM
demodulation is performed on the received signal y'(t), g-'[-] is used to represent the
GFDM demodulation process, and then a signal r(t) to bedespread can be expressed
as:
r(t)=g-'[y'(t)]
step 4: despreading the demodulated data, and integrating the obtained signals over a duration and making a judgement to obtain data estimated by the receiving end, wherein a despreading process is as below:
r(t) is despread by utilizing a spread spectrum sequence Cr(t) which is
generated locally and the same as that at the transmitting end: 1[y'(t)]C(t) M(t)=r(t)c,(t)=g- = g 1 [g[d(t)c(t)]]c,(t)=d(t)c(t)c,(t)
the signal is integrated over the duration:
q(t) = m(t)dt
where a pulse duration of the spread spectrum sequence c(t) is Tb, namely
fc(t)c,(t)dt = T and therefore, q(t) can be expressed as: f T, when d(t)=I --T[ when d(t)=-1
Figure 7: (a) is a picture of transmission in an experiment, and (b) is a received image in the case of a modulator structure of M=2 and K=29, a bit error rate of which is 0.0119. (c) is a received image in the case of a modulator structure of M=29 and K=2, a bit error rate of which is 0. According to the experimental results, in the case where a transmitted signal occupies the same bandwidth and channel resources are divided equally by subcarriers included in different modulation matrix structures, as a number of the subcarriers increases, performance of the GFDM spread spectrum system decreases, because when the number of the subcarriers is large, for a non-orthogonal multi-carrier technology, main lobe overlap between various subcarriers is serious, which in turn leads to a decrease in bit error performance. Therefore, on the one hand, it is required to design a reasonable subcarrier structure to avoid inter-carrier interference, and on the other hand, it is required to research and design a reasonable channel estimation method for the GFDM's modulator structure to remove influence of the channel on the system and improve performance of the GFDM spread spectrum system. The specific instances described above are only preferred examples of the present invention and do not limit the present invention in any form, and any simple modification and equivalent change made to the above examples according to the technical essence of the present invention falls within the protection scope of the present invention. Any reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. Where any or all of the terms "comprise", "comprises", "comprised" or ''comprising" are used in this specification (including the claims) they are to be
interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.
Claims (3)
1. A 5G multi-carrier spread spectrum underwater acoustic communication method, wherein the method comprises the following steps:
step 1: at a transmitting end, encoding source data, and performing a spread spectrum operation on an encoded source data by using a spread spectrum sequence; step 2: performing GFDM modulation on data after spread spectrum, and after that, adding a cyclic prefix to a modulated data to obtain data for transmission; step 3: at a receiving end, performing synchronization and GFDM demodulation on the modulated data, after the modulated data pass through an underwater acoustic channel; and
step 4: despreading a demodulated data, and integrating despread data over a duration and making a judgement to obtain data estimated by the receiving end;
wherein a spread spectrum process in the step 1 is as below:
the encoded source data is expressed by d(t ), the spread spectrum sequence is expressed by '7'l,and then the spread spectrum process can be expressed as:
d(t)= :d(n)g(t-nT,) c(t)= c(n)p(t-nT)
where values of d(n) and a pseudo-random sequence c(n) used for spreading spectrum are 1 or -1, g(t) and p(t) are rectangular pulses of a unit amplitude with TT durations b and c, respectively, N represents a length of the spread spectrum sequence, and in general, b=NTc; a sequence after spread spectrum p(t) is:
p(t)=d(t)c(t).
and a modulation process in the step 2 is expressed as below:
data after GFDM modulation is y(t), g[-] is used to express a GFDM modulation process, and then: y(t)=g[p(t)] = g[d(t)c(t)]
a discrete spread spectrum signal for GFDM adopting a BPSK modulation mode can be expressed as:
SMC-DS =E N0 G - dk[i]c[j]pT(t-iJ- jT)cos[2;r(f0 +kAf')t] k=0 i=-M j=0
where dii is data on a k-th subcarrier,CkI] represents a spread spectrum
sequence which is correspondingly multiplied byd[i] Nerepresents a number of
subcarriers,and Af'=1T is a subcarrier spacing.
2. The 5G multi-carrier spread spectrum underwater acoustic communication method according to claim 1, wherein a process of performing GFDM demodulation on received data in the step 3 is as below:
at the receiving end, on the premise of correct synchronization, the GFDM demodulation is performed on the modulated data y(t), g-1[] is used to represent the GFDM demodulation process, and then a signal r(t) to be despread can be expressed as:
r'(t=g-1[y'(t)]
3. The 5G multi-carrier spread spectrum underwater acoustic communication method according to claim 2, wherein a process of despreading the demodulated data in the step 4 is as below:
the signal r(t) to be despread is despread by utilizing a spread spectrum sequence Cr(t) which is generated locally and the same as that at the transmitting end:
M(t)= r(0c,(t)=g-'[y'(t]c,(t =g _'[g[d(t)c(t)]]c,(t)=d(t)c(t)c, (t)
the despread signal is integrated over the duration:
q(t) = m(t)dt
where a pulse duration of the spread spectrum sequence c(t) s , namely
UJb c(t)c,(t)dt T=
and therefore, q(t) can be expressed as:
q)f T, when d(t)=1 -T when d(t=-1
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2018/119346 WO2020113463A1 (en) | 2018-12-05 | 2018-12-05 | 5g multi-carrier spread spectrum underwater acoustic communication method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2018451596A1 AU2018451596A1 (en) | 2021-04-15 |
| AU2018451596B2 true AU2018451596B2 (en) | 2022-12-01 |
Family
ID=70974393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2018451596A Active AU2018451596B2 (en) | 2018-12-05 | 2018-12-05 | 5G multi-carrier spread spectrum underwater acoustic communication method |
Country Status (2)
| Country | Link |
|---|---|
| AU (1) | AU2018451596B2 (en) |
| WO (1) | WO2020113463A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112399302B (en) * | 2020-11-25 | 2022-11-18 | 维沃移动通信有限公司 | Audio playing method and device of wearable audio playing device |
| CN112995085B (en) * | 2021-02-08 | 2022-06-03 | 重庆邮电大学 | GFDM carrier system optimization method based on FW-CCDF algorithm |
| CN115173960B (en) * | 2022-06-29 | 2023-08-15 | 燕山大学 | Underwater sound communication method based on singlechip and underwater sound transducer |
| CN115001927B (en) * | 2022-07-12 | 2023-10-20 | 深圳智微信通技术有限公司 | Noise suppression method for carrier communication of voltage power line |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20160373172A1 (en) * | 2014-03-07 | 2016-12-22 | Vodafone Gmbh | Walsh-hadamard transformed gfdm radio transmission |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101166065B (en) * | 2007-07-24 | 2010-10-06 | 哈尔滨工程大学 | Deep sea remote water sound communication method |
| CN101534269B (en) * | 2009-04-14 | 2012-05-09 | 华南理工大学 | Underwater sound communication system |
| CN104753638B (en) * | 2015-03-02 | 2017-11-28 | 西安理工大学 | A kind of chaos spread spectrum underwater acoustic communication method |
| CN108933749B (en) * | 2018-06-08 | 2021-01-15 | 天津大学 | Aliasing generalized frequency division multiplexing multi-carrier modulation system |
-
2018
- 2018-12-05 AU AU2018451596A patent/AU2018451596B2/en active Active
- 2018-12-05 WO PCT/CN2018/119346 patent/WO2020113463A1/en active Application Filing
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20160373172A1 (en) * | 2014-03-07 | 2016-12-22 | Vodafone Gmbh | Walsh-hadamard transformed gfdm radio transmission |
Non-Patent Citations (4)
| Title |
|---|
| IRUTHAYANATHAN, N. et al., "Performance of Spread Spectrum Based Multi-Carrier System in Underwater Communication Using Transmitter Pre-Processing", IEEE Access, Vol. 4, 19 July 2016, pages 5128-5134 * |
| JINQIU, W. et al., "Emerging 5G Multicarrier Chaotic Sequence Spread Spectrum Technology for Underwater Acoustic Communication", Hindawi Complexity Volume 2018, 18 October 2018, Article ID 3790529, pages 1-7 * |
| JINQIU, W. et al., "GFDM-A potential technique for the next generation underwater communication systems with low PAPR", UACE2017 - 4th Underwater Acoustics Conference and Exhibition Proceedings, September 2017, pages 357-362 * |
| JINQIU, W. et al., "Influence of Pulse Shaping Filters on PAPR Performance of Underwater 5G Communication System Technique: GFDM", Hindawi Wireless Communications and Mobile Computing Vol. 2017, 28 Feb 2017, Article ID 4361589, pages 1-7 * |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2018451596A1 (en) | 2021-04-15 |
| WO2020113463A1 (en) | 2020-06-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2018451596B2 (en) | 5G multi-carrier spread spectrum underwater acoustic communication method | |
| CN109474305B (en) | 5G multi-carrier spread spectrum underwater acoustic communication method | |
| Wang et al. | Frequency-domain oversampling for zero-padded OFDM in underwater acoustic communications | |
| Han et al. | Filter design for generalized frequency-division multiplexing | |
| AU2018452060B2 (en) | Chaotic sequence-based 5G multi-carrier spread spectrum underwater acoustic communication method | |
| Nissel et al. | Enabling low-complexity MIMO in FBMC-OQAM | |
| CN101002448A (en) | Multicarrier modulation system having cyclic delay diversity | |
| Nissel et al. | Block frequency spreading: A method for low-complexity MIMO in FBMC-OQAM | |
| CN101631099A (en) | Multi-input and multi-output selectivity OFDM underwater sound communication system and method | |
| Kumar et al. | Recent trends in multicarrier underwater acoustic communications | |
| CN103888403B (en) | A kind of the high-speed Wavelet Multi Carrier spread spectrum communication system and method for suitable 5G networks | |
| Hara et al. | BER Comparison of DS-CDMA and MC-CDMAC for Frequency Selective Fading Channels | |
| CN103248377B (en) | Receiving-end signal interference elimination method of multi-carrier complementary code CDMA (code division multiple access) system | |
| WO2009043311A1 (en) | Time-frequency spreading method and apparatus in ofdma system | |
| Trivedi et al. | Carrier interferometry coded single carrier FDMA (CI/SC-FDMA) for next generation underwater acoustic communication | |
| Qi et al. | Spatial modulation-based orthogonal signal division multiplexing for underwater ACOMMS | |
| CN109495128B (en) | Chaos sequence-based 5G multi-carrier spread spectrum underwater acoustic communication method | |
| WO2012035345A2 (en) | Improvements in ofdm communication systems | |
| Shi et al. | Towards robust high speed underwater acoustic communications using chirp multiplexing | |
| Ghogho et al. | Training design for repetitive-slot-based CFO estimation in OFDM | |
| Shu et al. | Underwater chaos-based DS-CDMA system | |
| KR101499250B1 (en) | Apparatus and method for improving spectral efficiency of orthogonal frequency division multiplexing access | |
| Qi et al. | Orthogonal Signal Division Multiple Access for Multiuser Underwater Acoustic Networks | |
| Lee et al. | Use of training subcarriers for synchronization in low latency uplink communication with GFDM | |
| CN109450827A (en) | Channel estimation methods and system based on next-generation wireless waveform FBMC-OQAM |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) |