WO2005015865A1 - Multi-carrier communication apparatus with adaptive transmission according to transmission path fluctuations - Google Patents
Multi-carrier communication apparatus with adaptive transmission according to transmission path fluctuations Download PDFInfo
- Publication number
- WO2005015865A1 WO2005015865A1 PCT/JP2004/011649 JP2004011649W WO2005015865A1 WO 2005015865 A1 WO2005015865 A1 WO 2005015865A1 JP 2004011649 W JP2004011649 W JP 2004011649W WO 2005015865 A1 WO2005015865 A1 WO 2005015865A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- transmission path
- signal
- carrier
- communication apparatus
- transmission
- Prior art date
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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B14/00—Transmission systems not characterised by the medium used for transmission
- H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
- H04B14/023—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse amplitude modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/54—Systems for transmission via power distribution lines
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03159—Arrangements for removing intersymbol interference operating in the frequency domain
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0004—Modulated-carrier systems using wavelets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/003—Arrangements for allocating sub-channels of the transmission path
- H04L5/0044—Arrangements for allocating sub-channels of the transmission path allocation of payload
- H04L5/0046—Determination of how many bits are transmitted on different sub-channels
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
- H04B2203/5416—Methods of transmitting or receiving signals via power distribution lines by adding signals to the wave form of the power source
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
- H04B2203/5425—Methods of transmitting or receiving signals via power distribution lines improving S/N by matching impedance, noise reduction, gain control
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5462—Systems for power line communications
- H04B2203/5491—Systems for power line communications using filtering and bypassing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
- H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
- H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03375—Passband transmission
- H04L2025/03414—Multicarrier
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/0202—Channel estimation
- H04L25/022—Channel estimation of frequency response
Definitions
- This invention relates to a communication apparatus and a coirununicationmethodusingmulti-carrier transmission system, particularly, to a communication apparatus and a communication method which used a multi-carrier transmission system (Digital Wavelet Multi Carrier transmission system, hereinafter, 10 referred to as DWMC transmission system) which carries out data transmission by digital modulation and demodulation processing which used a real coefficient wavelet filter bank which is more suitable for a power line transmission path and a transmission path such as a telephone line.
- DWMC transmission system Digital Wavelet Multi Carrier transmission system
- OFDM Orthogonal Frequency 20 Division Multiplexing
- Wavelet based OFDM Orthogonal Frequency 20 Division Multiplexing
- the wavelet base has a resistance property to inter-carrier interference since a side lobe of an amplitude spectrum is low, and is of an excellent 25 characteristic.
- GI guard inverval
- the wavelet based OFDM it- is not necessary. This improves transmission efficiency. Since processing of the FFT based OFDM is known well, an explanation will be omitted.
- the wavelet based OFDM is digital modulation and demodulation processing which used a real coefficient wavelet filter bank, it is a multi-carrier system of a kind, and is a thing which generates a transmission signal by combining a plurality of digital modulation waves by the real coefficient filterbank.
- PAM Pulse Amplitude Modulation
- Data transmission by a DWMC transmission system is transmitted in such a manner that an impulse response of each sub carrier is overlapped in each sub carrier as shown in Fig.20.
- Each transmission symbol becomes such a time wave that an impulse response of each sub carrier was combined as shown in Fig. 21.
- An example of the amplitude spectrum is shown in Fig.22.
- a DWMC transmission frame In the DWMC transmission system, approximately tens of ⁇ hundreds of transmission symbols of Fig. 20 are collected to configure one transmission frame.
- a configuration example of a DWMC transmission frame is shown in Fig. 23.
- this DWMC transmission frame in addition to an information data transmission symbol, a preamble symbol etc. , which are used for carrier detection, synchronization, equalization and so on, are included.
- a conceptual configuration of a power line communication apparatus in case that the DWMC transmission systemwas adopted is shown in Fig.19. Firstly, in a transmitting device 299, bit data is converted into symbol data by a symbol mapper 210, and in accordance with each symbol data, symbol mapping (PAM) is carried out.
- PAM symbol mapping
- a sample value of a time axis waveform is generated, and a sample value sequence, which represents a transmission symbol, is generated.
- a D/A converter 240 it is converted from this sample value sequence to a base band analog signal waveform, which is continued in terms of time, and transmitted.
- a reception signal is converted into a digital signal in an A/D converter 310, and wavelet-converted so as to be able to handle phase information in a complex wavelet converter 320, and in a carrier detector 330, presence or absence of the reception signal is detected, and in a synchronous circuit 340, synchronizing timing is extracted from the reception signal, and in an equalizer 350, the reception signal is compensated so as to cancel influence of a transmission path, and in a transmission path estimator 370, a state of a power line transmission path is estimated, and in a judging unit 380, the reception signal is judged by use of a threshold level.
- the number of pieces of the sample values on a time axis, which are generated by inverse wavelet conversion, is normally 2 n (n is a positive integer) pieces .
- transmission path estimation which is carried out in a receiving device, can not follow sufficiently to instantaneous fluctuation and periodical fluctuation of wide-band noise or narrow-band noise, or instantaneous fluctuation and periodical fluctuation which come up with amplitude fluctuation and phase fluctuation of a transmission path itself, when transmissionpath estimation is simply carried out only once in a certain cycle, in a power line transmission path.
- the power line transmission path an attenuation characteristic of the power lien transmission path is shown in Fig.24.
- Fig.25 is a view which shows a group delay characteristic of the power line transmission path.
- transmission path estimation which is carried out in a receiving device, can not follow sufficiently to instantaneous fluctuation and periodical fluctuation of wide-band noise or narrow-band noise, or instantaneous fluctuation and periodical fluctuation which come up with amplitude fluctuation and phase fluctuation of a transmission path itself, when transmission path estimation is simply carried out only once in a certain cycle, in a power line transmission path.
- this power line communication apparatus it is requested to sufficiently take hold of a transmissionpath state, and to heighten transmission efficiency.
- This invention is to provide a communication apparatus which solves the above-describedproblem, andwhich sufficiently takes hold of a power line transmission path characteristic, and which follows to various transmission path fluctuation, and which can heighten transmission efficiency.
- This invention is a communication apparatus which carries out multi-carrier modulation processing, and a receiving device is equippedwith anA/D converter which converts an analog signal which was received, into a digital signal, a converter which generates an in-phase signal and a orthogonal signal by converting a reception signal, a carrier detector for detecting the reception signal, a synchronous circuit for being synchronized with the reception signal, an equalizer for compensating a distorted signal due to influence of a transmission path, a noise detector which detects presence or absence of narrow-band noise in each sub carrier band by use of a signal which was converted by the converter, a transmission path estimator which determines a multi-value level of primary modulation which is used by each sub carrier of a symbol mapper in a transmitting device, by use of a signal which is
- Fig.l is a block diagram which shows a receiving device in an embodiment 1 of this invention.
- Fig.2 is a viewwhich shows a scatter of an equalizer output signal.
- Fig.3 is a view which shows a noise characteristic in a power line transmission path.
- Fig.4 is a block diagram which shows a receiving device in an embodiment 2 of this invention.
- Fig.5 is a view which shows a noise characteristic in such a case that wide-bandnoise was added in a power line transmission path.
- Fig.6 is a frame configuration view for explaining an operation of a normal transmission path estimator.
- Fig.7 is a frame configuration view in such a case that transmission path estimation is carried out by use of time of a power supply cycle.
- Fig.8 is a block diagram of a receiving device in an embodiment 5 of this invention.
- Fig.9 is a frame configuration view in such a case that transmission path estimation is carried out by use of a transmission path estimation exclusive use frame and a data frame .
- Fig.10 is a graph which shows CINR in such a case that there was almost no transmission path fluctuation in case that transmission path estimation was carried out at a plurality of times .
- Fig.11 is a graph which shows CINR in such a case that there is transmission path fluctuation in case that transmission path estimation was carried out at a plurality of times.
- Fig.12 is a view of an amplitude spectrum in a DWMC transmission system.
- Fig.13 is a pattern diagram of a level of a signal which was received.
- Fig.14 is a pattern diagram at the time when a gain of an amplifier of a transmitting device was lowered by only 30dB.
- Fig.15 is a pattern diagram of a level of a signal which is received at the time when gains of sub carriers up to sub carrier number 1 ⁇ 100 were lowered by only 6dB.
- Fig.16 is a pattern diagram of a level of a signal which is received at the time when gains of sub carriers up to' sub carrier number 1 ⁇ 100 were lowered by 12dB, and gains of sub carriers up to sub carrier number 101-200 were lowered by only 6dB.
- Fig.17 is a pattern diagram of a level of a signal which is received at the time when gains of sub carriers up to sub carrier number 1 ⁇ 100 were lowered by 18dB, and gains of sub carriers up to sub carrier number 101 ⁇ 200 were lowered by 12dB, and gains of sub carriers up to sub carrier number 201 ⁇ 300 were lowered by only 6dB.
- Fig.18 is a pattern diagram of a transmission path estimation characteristic in such a case that a dynamic range is insufficient.
- Fig.19 is a view which shows a power line communication apparatus in a conventional system.
- Fig.20 is a view which shows a wavelet waveform example.
- Fig.21 is a view which shows a transmission waveform example in the DWMC transmission system.
- Fig.22 is a view which shows a transmission spectrum example in the DWMC transmission system.
- Fig.23 is a view which shows a configuration example of an inside of a transmission frame in the DWMC transmission system.
- Fig.24 is a viewwhich shows an attenuation characteristic of a power line transmission path.
- Fig.25 is a view which shows a group delay characteristic of a power line transmission path.
- Fig.26 is a view which shows a frame configuration example of a communication apparatus in an embodiment 22 of this invention.
- Fig.l is a block diagram which shows a receiving device in an embodiment 1 of this invention. Inpassing, a transmitting device is the same as the transmitting device 299 of Fig.19, as to which an explanation was carried out in the conventional technology.
- 310 designates an A/D converter which converts an analog signal into a digital signal
- 320 designates a complex wavelet converter which generates a in-phase signal and an orthogonal signal by wavelet-converting a reception signal
- 330 designates a carrier detector for detecting a transmission signal which is transmitted from a transmitting device
- 340 designates a synchronous circuit for synchronizing with the reception signal
- 350 designates an equalizer for compensating a signal which was distorted by influence of a transmission path
- 360 designates a noise detector which detects presence or absence of narrow-band noise in each sub carrier band, by use of a signal after complex wavelet conversion
- 370 designates a transmission path estimator which determines primary modulation which is used in each sub carrier of a symbol mapper in a transmitting device, by use of a signal which is outputtedfromthe equalizer 350 and information of presence or absence of narrow-band noise which is outputted from the noise detector
- 380 designates a judging unit which carries
- Fig.1 is a viewwhich shows a scatter of an equalizer output signal
- Fig.3 is a view which shows a noise characteristic in a power line transmission path.
- a reception signal is converted from an analog signal into a digital signal in the A/D converter 310, and in the complex wavelet converter 320, a digital signal, which was received, is wavelet-converted, and in the carrier detector 330, a signal, which is transmitted from the transmitting device, is detected, and in the synchronous circuit 340, wavelet conversion timing is adjudted of the complex wavelet converter 320, so as to be synchronized with a reception signal by use of a preamble signal, and in the equalizer 350, influence of a transmission path is removed, and in the noise detector 360, narrow-band noise, which exists in a use band, is detected, and in the transmissionpath estimator 370, a state of a transmission path is estimated, and a primary modulation system of a symbol mapper which is used in the transmitting device is determined, and in the judging unit 380, judgment is carried out by use of a signal which is outputted from the equalizer 350.
- Fig.2 shows a scatter (all sub carrier portions) of an equalizer output of the receiving device in case that all sub carriers 2PAM were selected in the symbol mapper of the transmitting device.
- CINR Carrier power to (Interference-plus-Noise) power Ratio
- those existing systems exist as narrow-bandnoise to the power line communication, as shown in Fig.3.
- these narrow-band noises exist on a steady basis, since CINR is deteriorated in a certain sub carrier at the time of transmission path estimation, it is possible to deal with, by making a sub carrier, which is using the same band as that band, non-use.
- these narrow-band noise levels exist at a noise level or less, which was obtained at the time of transmission path estimation, on a steady basis, even if narrow-band noise does not exist, CINR is not deteriorated, and therefore, it does not become a problem.
- noise detection is carried out by the noise detector 360.
- this detection result is also used as information for estimation by the transmission path estimator 370. The way to deetct noise detection is concretely explained.
- the noise detector 360 obtains an average value, median or the like of all sub carriers, checks a sub carrier, which has a large value of for example, 12dB or more, detects such sub carrier as "having narrow band noise" and transfers this information to the transmission path estimator 370. In case that the system becomes unstable, the transmission path estimator inhibits to use of the sub carrier which was checked here .
- the communication apparatus of the present invention is explained as the power line communication.
- the power line communication is one example of the transmission line which causes irregularly the narrow band noises.
- the present invention is not limited to the power line communication.
- the complex wavelet converter 320 is used, but a communication apparatus of this invention is not restricted to this, and it is possible to apply to such a wavelet converter that a phase of each sub carrier can be confirmed.
- FIG. 4 is a block diagram which shows a receiving device in an embodiment 2 of this invention. Inpassing, a transmitting device is the same as the transmitting device 299 of Fig.19.
- a difference between the receiving devices of Fig.4 and of Fig.l is only an AGC (Automatic Gain Control) circuit 390. Since other circuits are the same as the circuits which were explained in Fig.l, descriptions are pursuant to the descriptions in the embodiment 1.
- 390 designates anAGC circuit which automatically adjust a gain of a reception signal .
- Fig.5 is a view which shows a noise characteristic in case that wide-band noise was added in a power line transmission path.
- a difference from the embodiment 1 is to carry out noise detection by the noise detector 360 including a gain which is used by the AGC circuit.
- the noise detector 360 including a gain which is used by the AGC circuit.
- presence or absence of narrow-band noise can be detected, and in addition to this detection, by detecting a gain of the AGC circuit, it becomes possible to know influence of wide-band noise, which could not be known in this embodiment 1.
- Fig.5 shows an amplitude spectrum of a power line transmissionpathbypresence or absence of an electric equipment which continuously generates impulse noise of a high level in a time axis.
- the noise detector 360 considering that a system has becomes unstable due to random wide-band noise when wide-band noise exists by an output from the AGC circuit 390 and retransmission occurs frequently in normal transmissionpath estimation, mitigates a thresholdvalue which is used for transmission path estimation and transmission path estimation is carried out at a plurality of times, and, in that state, determines primarymodulation of each sub carrier by using a minimum CINR value in each sub carrier. By doing in this manner, even under a power line communication transmission path in which various noises exist, it becomes possible to carry out good communication.
- Fig.6 shows a frame configuration view for explaining an operation of a normal transmission path estimator.
- a transmissionpath estimation frame is added in a frame to be transmitted and received (in the figure, a "CE frame” is the “transmission path estimation frame”) .
- this transmission path estimation frame is used again on an irregular basis, when a transmission path fluctuates significantly, and if a past transmission path estimation result is used, many errors will be generated, and as a result, it comes to be in such a state that retransmission occurs frequently.
- the transmissionpath estimator 370 in the embodiment 3 of this invention carries out an operation of transmission path estimation for a power supply cycle 1 cycle portion, for example, by use of a transmission path estimation frame continuously during a period of a power supply cycle.
- a transmission path estimation frame continuously during a period of a power supply cycle.
- the transmissionpath estimator 370 in this embodiment in case that, at that time, fluctuation of noise and fluctuation of a transmission path exist in 1 cycle, but in each sub carrier, influence of transmission path fluctuation is smaller than a threshold value (in case that it does not have influence on errors) , becomes to maintain good transmission efficiency by use of that sub carrier even if there is fluctuation.
- a threshold value in case that it does not have influence on errors
- a point on which this embodiment is different from a conventional system is such a point that a judgment signal from the judging unit 380 is inputted to the transmission path estimator 370.
- transmissionpath estimation is carried out once, and next transmission path estimation will be carried out in case that a transmission path fluctuated significantly, and in case that it exceededmaximum time of a cycle for carrying out transmission path estimation, and so on. It is normal to use an exclusive use frame as a transmission path estimation frame in this case.
- Fig.9 is a frame configuration view in case of carrying out transmission path estimation by use of a transmission path estimation exclusive use frame and a data frame.
- the judgment feed back type circuit configuration of the receiving device of this embodiment is applicable also to the receiving device of the embodiment 1 or 2.
- the suchlike configuration it is possible to carry out transmission path estimation by use of a normal transmission path estimation exclusive use frame and a data frame, and therefore, as a result, it is possible to heighten transmission efficiency.
- a transmission path estimator which is used in a communication apparatus in an embodiment 6 of this invention, will be described.
- a point, which is different from the embodiment 5, is a transmission path estimating method by use of a data frame of the transmission path estimator 370.
- a transmission path estimator In case of carrying out transmission path estimation, required is an average of a symbol, which is a target for averaging noise, or more (the number of necessary symbols is assumed to be S) . However, there is no such guarantee that each data frame is composed of S symbol or more. On that account, a unit to be averaged is set to S symbol unit, but not a frame unit, and averaging is to be continued until reaching to the S symbol, even if a frame is changed. Concretely speaking, a transmission path estimator carries out averaging in a form which is as follows. Generally, a transmission path estimator 370 can complete transmission path estimation in 1 frame, if symbol number necessary for transmissionpath estimation is entered in 1 frame which is received by a receiving device.
- a transmission path estimator 370 of a communication apparatus in an embodiment 7 of this invention will be described.
- As a block configuration of the communication apparatus of this embodiment used is the block configuration of the communication apparatus whichwas described in the conventional system as shown in Fig.19 or in the embodiment 5.
- FIG. 8 Atransmissionpath estimator of a communication apparatus in an embodiment 8 of this invention will be described.
- a block configuration of the communication apparatus of this embodiment used is the block configuration of the communication apparatus which is described in the embodiment 1, 2 or 5, and as an operation of the transmission path estimator 370, transmission path estimation is carried out at a plurality of times .
- the transmission path estimator 370 in case of carrying out transmission path estimations at a plurality of times, how to determine a transmission path estimation value will be shown.
- Transmission path estimation of the transmission path estimator 370 is carried out bymeasuring CINR in each sub carrier in a reception signal, but since a transmission path fluctuates periodically or non-periodically, in case of a transmissionpath such as a power line, in case that transmission path estimation was carried out at a plurality of times, a transmission path estimation value of each sub carrier shows almost the same value, and fluctuates significantly.
- Fig.10 is a graph which shows CINR in case that there was almost no transmissionpath fluctuation in case that transmission path estimation was carried out at a plurality of times. In case of Fig.10, there is simply influence due to only background noise such as Gauss noise.
- the transmission path estimator 370 uses a maximumvalue in each sub carrier as an initial value, to a result which was obtained by transmission path estimations at a plurality of times, and uses a median in case that retransmission from the transmitting device 299 becomes to occur at many times, and uses a minimumvalue if communication does not become stable .
- the median since calculation such as SORT becomes enormous, a difference (e.g., 2dB) of the maximum value and the median has been obtained statistically, and by utilizing that value and the maximum value, it is also possible to obtain a result which is equivalent to that at such time that the median was used.
- a block configuration of the communication apparatus in this embodiment is the same block configuration as that described in the embodiment 8.
- As a transmission path for which the transmission path estimator 370 estimates, considered is almost the same transmission path as the transmission path which was considered in the embodiment 8.
- the transmission path estimator 370 in this embodiment, controls in such a manner that transmission efficiency in an entire system including retransmission etc.
- Fig.11 shown is a graph which shows CINR in case that there is transmission path fluctuation in case that transmission path estimation was carried out at a plurality of times.
- every time transmission fluctuation occurs errors are increased, depending on its range, and there is such a possibility that, even if error correction is carried out, a frame at that time becomes to be retransmitted.
- the transmission path estimator 370 in this embodiment on the basis of the above-described knowledge, can control in such amanner that transmission efficiency in an entire system including retransmission etc.
- a transmission path which is almost the same as the transmission path which was considered in the embodiment 10.
- a transmission path as shown in Fig.11 every time transmission path fluctuation occurs, errors are increases, depending upon its range, and there is such a possibility that, even if error correction is carried out, a frame at that time becomes to be retransmitted.
- the transmission path estimator 370 in this embodiment is designed to carry out transmission path estimation 2 times with timing which is not synchronized with a power supply cycle or its half cycle, to a transmission path estimation request, and to select a value in which CINR is larger, in each sub carrier, by utilizing a transmission path estimation result which was obtained.
- the transmission path estimator 370 in this embodiment is designed to carry out transmission path estimation 2 times with timing which is not synchronized with a power supply cycle or its half cycle, to a transmission path estimation request, and to select a value in which CINR is larger, in each sub carrier, by utilizing a transmission path estimation result which was obtained.
- Fig.23 is a view which shows a configuration example of an inside of a transmission frame in a DWMC transmission system. It is assumed that a frame configuration of a reception signal is transmitted by a frame which is composed of a preamble signal necessary for synchronization and equalization processing and a signal for information as in Fig.23.
- condition of a power line transmission path changes vary slowly, as compared to a wireless transmission path.
- instantaneous fluctuation it is generatedbyON/OFFof an electric equipment, andsoon.
- transmissionpath fluctuation which was synchronizedwith apower supply, and so on, are also conceivable.
- the transmission path estimator 370 in this embodiment on the basis of the above-described knowledge, is enough if it carries out transmission path estimation in a manner of a long cycle (at an interval from second to minute) , to very slow transmission path fluctuation, and has a necessity to carry out re-transmission path estimation since a transmission path state changes significantly, to instantaneous fluctuation due to ON/OFF of an electric equipment .
- a block configuration of a communication apparatus used is the block configuration of the communication apparatus of the conventional system of Fig.19 or the embodiment 1 or 2.
- CINR is obtained, and primary modulation, which is used in a symbol mapper of a transmitting device, is determined, and each parameter is set up so as to transmit with maximum efficiency in a transmission path through which communication is carried out.
- the communication apparatus of this embodiment carries out an operation as follows, on the basis of the above-described knowledge.
- the transmission path estimator 370 in case that a transmission path itself is not congested and in case that an amount of data to be transmitted is smaller than transmission path capacity (capacity which was obtained by transmission path estimation), is operated so as to lower by 1 rank (e.g., from 4PAM to 2PAM) , to a multi-value level which is judged in the vicinity of a threshold value, or to give a margin (e.g., 2dB) to all threshold values, or further, to determine a multi-value level by use of a minimum value in case that transmission path estimation is carried out at a plurality of times.
- 1 rank e.g., from 4PAM to 2PAM
- a multi-value level which is judged in the vicinity of a threshold value
- a margin e.g., 2dB
- this system is applicable not only to the wavelet conversion, but also tomuti-carrier communicationwhich realizes another low side lobe spectrum, by use of OFDM/OQAM (in this case, a multi-value level is MQAM: M is a multi-value number), Filtered OFDM, Filterred Mutitone systems etc.
- this system is also applicable to a FET (Fast
- the transmission path estimator 370 of a communication apparatus in an embodiment 14 of this invention will be described.
- a block configuration of a communication apparatus used is the power line communication apparatus of the conventional system of Fig.19 or the embodiment 1 or 2.
- CINR is obtained, and primary modulation, which is used in a symbol mappter of a transmitting device, is determined, and each parameter is set up so as to transmit with maximum efficiency in a transmission path through which communication is carried out.
- the transmission path estimator 370 of this embodiment carries out an operation as follows, on the basis of the above-described knowledge.
- this system is applicable not only to the wavelet conversion, but also to multi-carrier communication which realizes another low side lobe spectrum, by use of OFDM/OQAM (in this case, a multi-value level is MQAM: M is a multi-value number) , etc.
- this system is also applicable to a FET (Fast Fourier Transform) based multi-carrier communication system (for example, ADSL, 802.11a and g) in which a characteristic is deteriorated but which has been often used since old times.
- FET Fast Fourier Transform
- a characteristic is deteriorated but which has been often used since old times.
- a sub carrier which can be used, is limited to, for example, only a sub carrier which has an even number.
- inter-carrier interference due to collapse of orthogonality can be reduced significantly, and therefore, even if a sort of group delays exist, it is not almost affected by inter-carrier interference, and therefore, there is such a possibility that a transmission speed is improved as a total system.
- there occurs almost no overlap with an adjacent carrier there is a resistance property to frequency deviation.
- Fig.22 is a view which shows a transmission spectrum example in a DWMC transmission system.
- frequency utilization efficiency is lowered, but in a transmission path in which group delay deviation is large, inter-carrier interference canbe reduced significantly, and in addition, there is a resistance property to frequency deviation, and therefore, there is such a possibility that a transmission speed is improved as a total system.
- the transmission path estimator 370 of a communication apparatus in an embodiment 16 of this invention will be described.
- a block configuration of a communication apparatus used is the block configuration of the communication apparatus of the conventional system of Fig.19 of the embodiment 1 or 2.
- output power of the transmitting device 299 is smaller than maximum power, or maximum power required by the law.
- the communication apparatus calculates how much gain of an amplifier of the transmitting device has to be increased so as to realize the desired transmission speed, by use of a transmission path estimation result at that time, and on the basis of that calculation result, controls transmission power of the transmitting device 299.
- a sub carrier which is using the same band as a band which is used by a partial existing system (e.g., amateur radio etc.), is made to be of non-use since it becomes an obstacle to a existing system.
- Fig.12 is a view of an amplitude spectrum in a DWMC transmission system.
- Fig.12 shows an amplitude spectrum in such a case that a sub carrier, which is using the same band as a band which is used by amateur radio, was made non-use.
- a notch of 30dB or more is formed. This can be realized since a Wavelet based sub carrier is of a low side lobe amplitude spectrum.
- Fig.22 shown is a transmission spectrum example in the DWMC transmission system.
- a first side lobe of an amplitude spectrum of a sub carrier which is used here is -35dB.
- the transmission path estimator 370 in this embodiment so as for the notch to become deeper only by such a portion that a gain of an amplifier of the transmitting device 299 was increased, further makes a sub carrier non-use in the vicinity of them.
- an increase amount of a gain of an amplifier of the transmitting device 299 and the number of sub carriers which are made non-use are determined uniquely.
- a dynamic range of a receiving device is assumed to be 40dB.
- the number of all sub carriers is assumed to be 300.
- a transmission path is a static transmission path and does not move.
- a noise level of a transmission path is measured.
- the noise level is easily obtained by use of a coefficient of an equalizer and a gain of AGC.
- normal transmissionpath estimation " a transmitting device makes transmission with maximum power
- SNR signal power to noise power ratio
- Fig.13 is a pattern diagram of a received signal revel. Fig.13 shows a noise level at the time of no reception signal, a signal level received by a receiving device when a transmitting device sent a signal with maximum power, and CINR which is obtained at the time of transmission path estimation.
- CINR which is obtained at the time of transmission path estimation, becomes maximum 40dB, minimum 2OdB, since a dynamic range of the receiving device
- the transmission path estimator 370 of a communication apparatus in an embodiment 19 of this invention will be described. It is assumed that a block configuration of a communication apparatus in this embodiment is the same block configuration of the communication apparatus as in the embodiment 18. In the method of the embodiment 18, it was possible to suppresspower consumptionof the transmittingdevicebylowering transmission power, and to reduce interference to another existing system, but it was not possible to improve transmission speed. In this embodiment, in addition to the characteristics of the embodiment 18, a method of improving a transmission speed of a communication apparatus will be described.
- the transmission path estimator " 370 obtains SNR of a transmission path at the time of transmission path estimation, in the same manner as in the embodiment 18.
- Calculated is how much a gain can be lowered by, in each sub carrier, in order to realize a maximum transmission speed andminimum transmission power by use of SNR which was obtained in each sub carrier.
- a multi-value level which us used in each sub carrier, or information, which corresponds to it, is informed from a receiving device to the transmitting device 299, at the time of transmission path estimation.
- information of a gain which is controlled in each sub-carrier is also informed.
- a transmitting device carries out primary modulation of each sub carrier by use of information of a multi-value level, and controls transmission power of each sub carrier by use of the gain information.
- the transmission path estimator 370 is designed to carry out transmission path estimation at a plurality of times to a transmission path estimation request.
- a transmission path is a static transmission path and does not move.
- normal transmission path estimation (a transmitting device makes transmission with maximum power) is carried out. From a transmission path estimation result in a receiving device, only a gain of a sub carrier, which showed a maximum multi-value level, is lowered by only a in a single uniform way.
- a is obtained from a difference of threshold values which are used at the time of determining a multi-value level.
- a use multi-value level is set to 16PAM ⁇ 2PAM, and a difference of each threshold value is se to 6dB in a single uniform way.
- a is 6dB.
- a first time transmission path estimation result is informed to the transmitting device 299 by a multi-value level or informationwhich corresponds to it, and such a fact that a second time transmission path estimation will be carried out is also informed at the same time.
- the transmitting device 299 lowers a gain of only a sub carrier of the maximum multi-value level (here, 16PAM) by only 6dB to transmit, and in a receiving device, the second transmission path estimation is carried out, and comparing with a first time result, if a transmission speed is lowered, transmission path estimation is finished at the second time, and the last (here, first time) transmission path estimation result is informed to the transmitting device 299 as a result to this time's transmission path estimation request. If a transmission speed at the second time is faster than a transmission speed at the first time, third time transmission path estimation is carried out.
- a sub carrier of the maximum multi-value level here, 16PAM
- the transmitting device 299 lowers a gain of only a sub carrier of the maximummulti-value level by only 6dB, to transmit, and in the receiving device, third time transmission path estimation is carried out.
- the transmitting device 299 lowers a gain of a sub carrier whose gain is lowered at both the first, second time, by only its sum 12dB.
- N-th time transmission path estimation used are a transmissionpath estimation result which was obtained at (N-l)-th time and accumulated gains.
- Fig.15 is a pattern diagram of a level of a signal which is received at the time when ' gains of sub carriers up to sub carrier numbers 1 ⁇ 100 were lowered by only 6dB
- Fig.16 is a pattern diagram of a level of a signal which is received at the time when gains of sub carriers up to sub carrier number 101 ⁇ 200 were lowered by only 6dB
- Fig.17 is a pattern diagram of a level of a signal which is received at the time when gains of sub carriers up to sub carrier number 1 ⁇ 100 were lowered by 18dB, and gains of sub carriers up to sub carrier number 101 ⁇ 200 are lowered by 12dB, and gains of sub carriers up to sub carrier number 201 ⁇ 300 are lowered by only 6dB.
- Fig.13 is a pattern diagram of a level of a signal which was received. In case that a transmitting device outputted with maximum power from Fig.13, a receiving
- a device can receive with maximum 80dB ⁇ N, minimum 60dB ⁇ N.
- a CI ⁇ R value which is obtained at the time of transmissionpathestimation, becomes maximum 4OdB, minimum20dB, since a dynamic range of the receiving device is 40dB.
- gains of sub carriers up to sub carrier number 1 ⁇ 100 which are selecting the maximum multi-value level (here, 16PAM) , are lowered by 6dB.
- gains of sub carriers up to sub carrier number 1 ⁇ 200, which selected 16PAM is lowered by 12dB, 6dB.
- CINR becomes 40dB, 36dB, 32dB.
- all sub carriers become to select 16PAM.
- gains are lowered by 18dB, 12dB, 6dB.
- 16PAM is selected in all sub carrier in the same manner as in the third time.
- processing is finished, and a third time's result is used for communication as a transmissionpath estimation result at this time.
- a third time' s speed and a fourth time's speed become the same by accident, but since an actual transmission path characteristic is complex, there is generally no case that they become the same.
- this processing is continued until such time that a transmission speed is deteriorated, and at such a time point that the speed was deteriorated, the last result is to be used as a transmission path estimation result at that time.
- transmissionpath estimation is usedwith limitation of 2 times, it is possible to effectively utilize a dynamic range of a receiving device by only a dB, as compared to such a case that this system is not used.
- a gain of only the maximum multi-value level was lowered, but it is possible to obtain the same advantage even without limiting to the maximum multi-value level (e.g., a gain is lowered in a sub carrier of 8PAMormore) .
- transmissionpath estimation has to be carried out at a plurality of times, but it is possible to control transmission power of a transmitting device by a simple produce, in a power line communication apparatus .
- a gain of the transmitting device 299 was controlled by use of the CINR value, but it is also possible to carry out power control of the transmitting device 299 by use of SNR of each sub carrier.
- the transmission path estimator 370 of a communication apparatus in an embodiment 21 of this invention will be described.
- a block configuration of a communication apparatus used is the block configuration of the communication apparatus of the conventional system of Fig.19 or the embodiment 1 or 2.
- transmission path estimation is carried out at a plurality of times, and at that time, a reception signal level is also measured (noise level measurement is unnecessary) .
- a reception level at the time of first transmission path estimation is (a) of Fig.18.
- a MAX level is extracted, and an offset level is set up, and a gain of a sub carrier, which is received with a level of (MAX level - offset level) or more, is lowered by only B in a single uniform way.
- second time transmission path estimation is carried out, and a transmission speed is compared with that of the first time, and if a transmission speed has been deteriorated, the last result of CINR and gain information are used as a transmission path estimation result .
- third time is carried out in the same manner.
- Fig.18 is a pattern diagram of a transmission path estimation characteristic in such a case that a dynamic range is insufficient.
- gains of sub carriers up to sub carrier number 1 ⁇ 100 are loweredby 18dB.
- second time transmission path estimation is carried out, and from a result of CINR, it is confirmed that a transmission speedhas bee improved.
- third time is carried out, depending upon setup of an offset value, gains of all sub carriers are further lowered by 18dB, and it is judged whether a transmission speed has been improved or not, and in case that it was deteriorated, transmission path estimation is finished, and the last CINR value and gain information are used as a final result.
- a second time's speed and a third time's speed become the same by accident, but since an actual transmission path characteristic is complex, we think that there is generally no such a case that they become the same.
- CINR may be determined by second time processing.
- a block configuration of a communication apparatus in an embodiment 22 of this invention used is the block configuration of the communication apparatus of the conventional system of Fig.19 or the embodiment 1 or 2.
- a frame configuration example of the communication apparatus in this embodiment is shown in Fig.26.
- Fig.26 is a view which shows the frame configuration example of the communication apparatus in the embodiment 22 of this invention.
- this frame configuration shows data which is transmitted toward a receiving device, on the basis of information which the transmitting device 299 obtained from the transmission path estimator 370 of a receiving device.
- PRE shows a preamble signal which is used in synchronization processing, equalization processing etc. of a receiving device
- SYNC shows a SYNC signal which identifies a data start
- TMI shows a signal which shows information based upon a transmission path estimation result
- FC shows a frame control signal
- PL shows an information signal.
- the information which is based upon a transmission path estimationresult of TMI maybe a result itselfwhichwas estimated by the transmission path estimator 370 of a receiving device, or information which defines modulation and demodulation, which are use in transmission and reception, on the basis of estimation.
- a control signal PRE and SYNC
- transmissionpath estimation information is placed at a forefront portion of the information signal .
- it is placedbefore SYNC, andbefore FC1.
- Embodiment 23 As a block configuration of a communication apparatus in an embodiment 23 of this invention, considered is the same block configuration as that of the communication apparatus which was disclosed in the embodiment 22.
- diversity frequency diversity, time diversity etc.
- the information is usedas the TMI signal .
- transmissionefficiency is lowered (there is such a possibility that the TMI signal becomes several ⁇ several dozen symbols) .
- Ahigh resistance property is required for ' the TMI signal.
- the high gain diversity processing is desired to be carried out to the TMI signal, only at such time that transmission path estimation was carried out, detailed transmission path estimation result information is exchangedina communication apparatus as the information signal, and that information is stored in a memory etc. , and in a normal communication state, transmitted is only information (INDEX etc.) fromwhich a location, in which that information is stored, is known. Since an amount of information which is necessary at this time is lessened (normally, several bits), it becomes possible to improve a diversity gain to a large extend, without lowering transmission efficiency. In passing, as a method of obtaining a high gain to the TMI signal, there is error correction, other than diversity, but high gain error correction is generally of large systemdelay.
- this system is applicable not only to the wavelet based OFDM, but also to muti-carrier communication which realizes another low side lobe spectrum, by use of OFDM/OQAM (in this case, a multi-value level of a primary modulation system is MQAM: M is amulti-value number) , FilteredOFDM, FilterredMutitone systems etc.
- MQAM multi-value level of a primary modulation system
- FilteredOFDM FilterredMutitone systems etc.
- a transmissionpath it is not limited to a transmission path of a power line, and it is possible to apply to a digital communication apparatus etc. which utilizes a power line as a transmission path.
- Acommunication apparatus which relates to this invention, becomes possible to follow sufficiently to various fluctuations of a transmission path such as a power line, and as a power line communication apparatus, or by applying to a high speed communication apparatus of another transmission path, it is useful.
- This invention is to provide a communication apparatus which solves the above-describedproblem, andwhich sufficiently takes hold of a power line transmission path characteristic, andwhich follows to various transmissionpath fluctuation, and which can heighten transmission efficiency.
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Power Engineering (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN200480022652XA CN1833421B (en) | 2003-08-07 | 2004-08-06 | Multi-carrier communication apparatus with adaptive transmission according to transmission path fluctuations |
EP04771624.6A EP1654849B1 (en) | 2003-08-07 | 2004-08-06 | Multi-carrier communication apparatus with adaptive transmission according to transmission path fluctuations |
ES04771624.6T ES2541682T3 (en) | 2003-08-07 | 2004-08-06 | Multi-carrier communication device with adaptive transmission according to transmission path fluctuations |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003-288747 | 2003-08-07 | ||
JP2003288747A JP4356392B2 (en) | 2003-08-07 | 2003-08-07 | Communication device |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005015865A1 true WO2005015865A1 (en) | 2005-02-17 |
Family
ID=34131528
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2004/011649 WO2005015865A1 (en) | 2003-08-07 | 2004-08-06 | Multi-carrier communication apparatus with adaptive transmission according to transmission path fluctuations |
Country Status (6)
Country | Link |
---|---|
US (3) | US7302240B2 (en) |
EP (2) | EP1654849B1 (en) |
JP (1) | JP4356392B2 (en) |
CN (3) | CN101714968B (en) |
ES (2) | ES2541682T3 (en) |
WO (1) | WO2005015865A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102420639A (en) * | 2011-10-19 | 2012-04-18 | 南京致德软件科技有限公司 | Low voltage power line high-frequency noise sampling and replaying system |
Families Citing this family (58)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2259442A1 (en) | 2002-01-24 | 2010-12-08 | Panasonic Corporation | Method of and system for power line carrier communications |
JP4356392B2 (en) * | 2003-08-07 | 2009-11-04 | パナソニック株式会社 | Communication device |
JP5052742B2 (en) * | 2004-07-22 | 2012-10-17 | パナソニック株式会社 | Transmitting apparatus and communication system using the same |
TWI271951B (en) * | 2004-12-15 | 2007-01-21 | Mediatek Inc | Impulse supression apparatus of OFDM system and impulse supression method thereof |
JP4606149B2 (en) | 2004-12-16 | 2011-01-05 | パナソニック株式会社 | Receiving apparatus and receiving method |
US8126065B2 (en) * | 2005-03-23 | 2012-02-28 | Sony Corporation | Automatic power adjustment in powerline home network |
JP2006295479A (en) * | 2005-04-08 | 2006-10-26 | Matsushita Electric Ind Co Ltd | Power line communications apparatus and power line communication method |
EP1718021B1 (en) * | 2005-04-29 | 2010-03-17 | Sony Deutschland GmbH | Receiving device and communication method for an OFDM communication system with a new preamble structure |
JP4731991B2 (en) * | 2005-05-16 | 2011-07-27 | パナソニック株式会社 | Multi-carrier communication apparatus and multi-carrier communication method |
US7907509B2 (en) * | 2005-05-26 | 2011-03-15 | Panasonic Corporation | Communication apparatus, integrated circuit and communication method |
JP4699113B2 (en) * | 2005-07-05 | 2011-06-08 | パナソニック株式会社 | Multi-carrier communication apparatus and multi-carrier communication method |
JP4895557B2 (en) | 2005-09-16 | 2012-03-14 | パナソニック株式会社 | Multi-carrier communication apparatus and multi-carrier communication method |
US7636553B2 (en) * | 2005-09-21 | 2009-12-22 | Broadcom Corporation | Double search user group selection scheme with range reduction for FDD multiuser MIMO downlink transmission with finite-rate channel state information feedback |
JP4749815B2 (en) * | 2005-09-27 | 2011-08-17 | パナソニック株式会社 | Multi-carrier communication apparatus, multi-carrier communication system, and multi-carrier communication method |
US8537819B2 (en) | 2005-11-10 | 2013-09-17 | Panasonic Corporation | Power line communication apparatus, power line communication method and communication apparatus |
JP4749840B2 (en) * | 2005-11-10 | 2011-08-17 | パナソニック株式会社 | Communication apparatus and communication method |
JP4649597B2 (en) | 2006-02-22 | 2011-03-09 | 独立行政法人産業技術総合研究所 | Data transmission device |
JP4821377B2 (en) * | 2006-03-08 | 2011-11-24 | 日本電気株式会社 | Multi-carrier transmission apparatus, multi-carrier transmission method and program |
JP4946121B2 (en) * | 2006-03-24 | 2012-06-06 | パナソニック株式会社 | Authentication relay device, authentication relay system, and authentication relay method |
US7912139B2 (en) * | 2006-04-03 | 2011-03-22 | Panasonic Corporation | Multi-carrier communication apparatus, power line communication circuit, and multi-carrier communication method |
JP2007281577A (en) * | 2006-04-03 | 2007-10-25 | Matsushita Electric Ind Co Ltd | Multicarrier receiver and receiving method |
US8045927B2 (en) * | 2006-04-27 | 2011-10-25 | Nokia Corporation | Signal detection in multicarrier communication system |
CN101079643A (en) * | 2006-05-26 | 2007-11-28 | 摩托罗拉公司 | Method and system for reducing the power consumption of wireless transmitter |
JP4907277B2 (en) * | 2006-09-15 | 2012-03-28 | パナソニック株式会社 | Power line communication apparatus, power line communication method, and power line communication system |
US7782934B2 (en) * | 2006-09-18 | 2010-08-24 | Silicon Image, Inc. | Parameter scanning for signal over-sampling |
EP1959626B1 (en) * | 2007-02-14 | 2009-01-21 | NTT DoCoMo Inc. | Receiver apparatus, transmitter apparatus and communication system for detecting a narrowband interference in a multi-carrier receiver signal |
EP1959625B1 (en) * | 2007-02-14 | 2009-02-18 | NTT DoCoMo Inc. | Receiver apparatus for detecting narrowband interference in a multi-carrier receive signal |
JP4964298B2 (en) * | 2007-04-12 | 2012-06-27 | シャープ株式会社 | COMMUNICATION DEVICE, COMMUNICATION METHOD, COMMUNICATION PROGRAM, AND RECORDING MEDIUM |
JP5448359B2 (en) * | 2007-05-30 | 2014-03-19 | パナソニック株式会社 | Power line communication method, power line communication apparatus, and power line communication system |
US8031586B2 (en) * | 2007-08-15 | 2011-10-04 | Nokia Corporation | Method and apparatus for transmitter timing adjustment |
JP2009088793A (en) * | 2007-09-28 | 2009-04-23 | Fujitsu Ltd | Synchronizing system, synchronizing signal transmitting apparatus, clock supplying apparatus, and synchronizing method |
US8411766B2 (en) | 2008-04-09 | 2013-04-02 | Wi-Lan, Inc. | System and method for utilizing spectral resources in wireless communications |
JP4962412B2 (en) * | 2008-05-27 | 2012-06-27 | 株式会社デンソー | Carrier sense circuit |
US8265214B2 (en) * | 2008-07-01 | 2012-09-11 | Qualcomm Incorporated | Method and apparatus for adaptive timing synchronization in a communication network |
JP5158958B2 (en) * | 2008-07-31 | 2013-03-06 | パナソニック株式会社 | OFDM symbol detection method, OFDM receiver, integrated circuit, and circuit module |
US8274885B2 (en) | 2008-10-03 | 2012-09-25 | Wi-Lan, Inc. | System and method for data distribution in VHF/UHF bands |
US8107391B2 (en) | 2008-11-19 | 2012-01-31 | Wi-Lan, Inc. | Systems and etiquette for home gateways using white space |
US8335204B2 (en) | 2009-01-30 | 2012-12-18 | Wi-Lan, Inc. | Wireless local area network using TV white space spectrum and long term evolution system architecture |
KR101510741B1 (en) * | 2009-03-06 | 2015-04-10 | 삼성전자주식회사 | A method for transmitting and receiving broadcasting signal in a wireless broadcasting communication system and a apparatus thereof |
US8937872B2 (en) | 2009-06-08 | 2015-01-20 | Wi-Lan, Inc. | Peer-to-peer control network for a wireless radio access network |
US8488663B2 (en) | 2009-09-23 | 2013-07-16 | Maxlinear, Inc. | Impulse noise mitigation under out-of-band interference conditions |
CN102648608B (en) * | 2009-11-27 | 2016-08-24 | 日本电气株式会社 | Wireless communication system, radio communication device and wireless communications method |
JP5719998B2 (en) | 2010-02-10 | 2015-05-20 | パナソニックIpマネジメント株式会社 | Transmission device, reception device, transmission method, and reception method |
KR101184902B1 (en) | 2011-02-14 | 2012-09-20 | 주식회사 파워챔프 | Method for receiver's Initial Gain Setting of Communication System |
JPWO2012157565A1 (en) * | 2011-05-13 | 2014-07-31 | 日本電気株式会社 | Wireless device, router, wireless system, and wireless transmission speed optimization method |
CN103107829B (en) * | 2011-11-09 | 2014-12-10 | 中国移动通信集团上海有限公司 | Opening and closing switching method and device of filtering device of power line communication system |
CN102523017B (en) * | 2011-12-01 | 2014-01-01 | 清华大学 | Chip of single-carrier ultra-wideband receiver |
JP5909417B2 (en) | 2012-07-13 | 2016-04-26 | ルネサスエレクトロニクス株式会社 | Semiconductor device and receiving device |
JP2014064100A (en) * | 2012-09-20 | 2014-04-10 | Aisin Seiki Co Ltd | Power line communication transceiver and power line communication method |
CN104079319A (en) * | 2013-03-26 | 2014-10-01 | 杨晨 | Carrier multi-mode and multi-channel system |
JP6259297B2 (en) * | 2014-01-29 | 2018-01-10 | ルネサスエレクトロニクス株式会社 | Signal processing apparatus, signal processing method, and program |
US9137074B2 (en) | 2014-02-13 | 2015-09-15 | Futurewei Technologies, Inc. | System and method for guard band utilization for synchronous and asynchronous communications |
JP6536988B2 (en) * | 2014-05-08 | 2019-07-03 | パナソニックIpマネジメント株式会社 | Transmitting terminal device, receiving terminal device, and power line communication system |
CN106302300B (en) * | 2015-06-24 | 2020-07-31 | 北京三星通信技术研究有限公司 | Method and device for transmitting and receiving signals based on filter bank multi-carrier system |
KR101746799B1 (en) * | 2015-11-04 | 2017-06-14 | 주식회사 쏠리드 | distributed antenna system |
CN112350747B (en) * | 2020-10-20 | 2021-12-10 | 华北电力大学 | PLC channel impulse noise detection method and system by using state estimation |
CN114598392B (en) * | 2022-03-22 | 2024-03-15 | 中山大学 | High-precision synchronization method between multi-dimensional optical modulator branches |
CN114553263B (en) * | 2022-04-27 | 2022-08-02 | 杭州禾迈电力电子股份有限公司 | Power line carrier communication device and method |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998010545A1 (en) * | 1996-09-02 | 1998-03-12 | Telia Ab | Improvements in, or relating to, multi-carrier transmission systems |
US20020137467A1 (en) * | 2001-01-16 | 2002-09-26 | Tzannes Marcos C. | Fast initialization using seamless rate adaptation |
US20030043732A1 (en) * | 2001-05-17 | 2003-03-06 | Walton Jay R. | Method and apparatus for processing data for transmission in a multi-channel communication system using selective channel transmission |
Family Cites Families (41)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62294339A (en) | 1986-06-13 | 1987-12-21 | Omron Tateisi Electronics Co | Distribution line communication equipment |
JP2720131B2 (en) | 1992-05-15 | 1998-02-25 | 株式会社日立製作所 | X-ray reflection profile measuring method and apparatus |
US5995539A (en) | 1993-03-17 | 1999-11-30 | Miller; William J. | Method and apparatus for signal transmission and reception |
US5497398A (en) | 1993-08-12 | 1996-03-05 | Aware, Inc. | Multi-carrier transceiver |
US5636246A (en) | 1994-11-16 | 1997-06-03 | Aware, Inc. | Multicarrier transmission system |
US5631610A (en) | 1996-01-25 | 1997-05-20 | Aware, Inc. | Single side-band modulation system for use in digitally implemented multicarrier transmission systems |
US6538986B2 (en) * | 1996-09-02 | 2003-03-25 | Stmicroelectronics N.V. | Data transmission system and method using nQAM constellation with a control channel superimposed on a user data channel |
ATE245324T1 (en) | 1996-09-02 | 2003-08-15 | St Microelectronics Nv | IMPROVEMENTS IN, OR RELATING TO, MULTI-CARrier TRANSMISSION SYSTEMS |
JPH1120131A (en) | 1997-07-03 | 1999-01-26 | Ryobi Ltd | Press plate gripper for printer |
JP3078262B2 (en) | 1997-08-28 | 2000-08-21 | 住友電気工業株式会社 | Communication device |
JPH11163807A (en) | 1997-09-29 | 1999-06-18 | Matsushita Electric Ind Co Ltd | Communication system, transmitter and receiver |
JP2920131B1 (en) | 1998-01-28 | 1999-07-19 | 株式会社次世代デジタルテレビジョン放送システム研究所 | OFDM signal transmission device |
JPH11313043A (en) | 1998-02-27 | 1999-11-09 | Nec Corp | Multicarrier transmission system, transmission equipment and transmission method |
JP3470583B2 (en) | 1998-03-05 | 2003-11-25 | 株式会社豊田中央研究所 | Receiving machine |
JP2967193B2 (en) | 1998-03-20 | 1999-10-25 | 郵政省通信総合研究所長 | Information transmission method using orthogonal wavelets |
CA2346714C (en) * | 1999-04-22 | 2007-07-10 | Nippon Telegraph And Telephone Corporation | Receiver for ofdm packet communication system |
US6570929B1 (en) * | 1999-07-08 | 2003-05-27 | Telefonaktiebolaget Lm Ericsson (Publ) | Power control scheme for maximizing carrier signal-to-noise ratio in multicarrier transmitters |
US6397368B1 (en) | 1999-12-06 | 2002-05-28 | Intellon Corporation | Forward error correction with channel adaptation |
US6442129B1 (en) | 1999-12-06 | 2002-08-27 | Intellon Corporation | Enhanced channel estimation |
US7027493B2 (en) * | 2000-01-19 | 2006-04-11 | Time Domain Corporation | System and method for medium wide band communications by impluse radio |
EP1134945B1 (en) | 2000-03-07 | 2008-05-14 | Alcatel Lucent | Method to determine a channel characteristic and discrete wavelet receiver to perform the method |
JP4337228B2 (en) * | 2000-04-13 | 2009-09-30 | ソニー株式会社 | OFDM receiving apparatus and method |
WO2001099362A2 (en) * | 2000-06-16 | 2001-12-27 | Inari, Inc. | Sliding-window processing for the reception of multicarrier signals |
US6754170B1 (en) * | 2000-09-29 | 2004-06-22 | Symbol Technologies, Inc. | Timing synchronization in OFDM communications receivers |
ES2188373B1 (en) * | 2001-05-25 | 2004-10-16 | Diseño De Sistemas En Silencio, S.A. | COMMUNICATION OPTIMIZATION PROCEDURE FOR MULTI-USER DIGITAL TRANSMISSION SYSTEM ON ELECTRICAL NETWORK. |
GB2376855A (en) * | 2001-06-20 | 2002-12-24 | Sony Uk Ltd | Determining symbol synchronisation in an OFDM receiver in response to one of two impulse response estimates |
WO2004014056A1 (en) * | 2001-08-04 | 2004-02-12 | Enikia Llc | Power line communication system |
JP3727283B2 (en) * | 2001-11-26 | 2005-12-14 | 松下電器産業株式会社 | Wireless transmission device, wireless reception device, and wireless transmission method |
JP3538187B2 (en) * | 2002-03-26 | 2004-06-14 | 株式会社東芝 | OFDM receiver and data demodulation method in OFDM receiver |
US7418026B2 (en) * | 2002-05-09 | 2008-08-26 | Sony United Kingdom Limited | Receiver for a multi-carrier modulated symbol |
JP2006505969A (en) * | 2002-05-28 | 2006-02-16 | アンペリオン,インコーポレイティド | A communication system that provides broadband communication using medium-voltage cables in power systems |
SG129231A1 (en) * | 2002-07-03 | 2007-02-26 | Oki Techno Ct Singapore Pte | Receiver and method for wlan burst type signals |
AU2003254284A1 (en) * | 2002-08-01 | 2004-02-23 | Aware, Inc. | Multi-tap frequency domain equalization with decision feedback and trellis decoding |
US7161896B1 (en) * | 2002-08-12 | 2007-01-09 | Cisco Systems Wireless Networking (Australia) Pty Limited | Channel estimation in a multicarrier radio receiver |
WO2004032347A1 (en) * | 2002-08-28 | 2004-04-15 | Agency For Science Technology And Research | Receiver having a signal reconstructing section for noise reduction, system and method thereof |
AU2003276972A1 (en) * | 2002-09-25 | 2004-04-19 | Enikia Llc | Method and system for timing controlled signal transmission in a point to multipoint power line communications system |
US7471745B2 (en) * | 2002-11-26 | 2008-12-30 | Texas Instruments Incorporated | Method and apparatus for channel quality metric generation within a packet-based multicarrier modulation communication system |
US20040105512A1 (en) * | 2002-12-02 | 2004-06-03 | Nokia Corporation | Two step synchronization procedure for orthogonal frequency division multiplexing (OFDM) receivers |
CN1643867B (en) * | 2003-06-22 | 2010-06-23 | 株式会社Ntt都科摩 | Device and method for estimating channels |
JP4356392B2 (en) * | 2003-08-07 | 2009-11-04 | パナソニック株式会社 | Communication device |
JP4291673B2 (en) * | 2003-11-11 | 2009-07-08 | 株式会社エヌ・ティ・ティ・ドコモ | OFDM receiver |
-
2003
- 2003-08-07 JP JP2003288747A patent/JP4356392B2/en not_active Expired - Lifetime
-
2004
- 2004-08-06 CN CN200910177316.7A patent/CN101714968B/en not_active Expired - Lifetime
- 2004-08-06 EP EP04771624.6A patent/EP1654849B1/en not_active Expired - Lifetime
- 2004-08-06 CN CN200480022652XA patent/CN1833421B/en not_active Expired - Lifetime
- 2004-08-06 ES ES04771624.6T patent/ES2541682T3/en not_active Expired - Lifetime
- 2004-08-06 ES ES10190984.4T patent/ES2539580T3/en not_active Expired - Lifetime
- 2004-08-06 CN CN201110034315.4A patent/CN102118347B/en not_active Expired - Lifetime
- 2004-08-06 EP EP10190984.4A patent/EP2293508B1/en not_active Expired - Lifetime
- 2004-08-06 WO PCT/JP2004/011649 patent/WO2005015865A1/en active Application Filing
- 2004-08-09 US US10/913,495 patent/US7302240B2/en active Active
-
2007
- 2007-10-12 US US11/871,820 patent/US7725081B2/en not_active Expired - Lifetime
-
2010
- 2010-05-21 US US12/785,163 patent/US8086194B2/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998010545A1 (en) * | 1996-09-02 | 1998-03-12 | Telia Ab | Improvements in, or relating to, multi-carrier transmission systems |
US20020137467A1 (en) * | 2001-01-16 | 2002-09-26 | Tzannes Marcos C. | Fast initialization using seamless rate adaptation |
US20030043732A1 (en) * | 2001-05-17 | 2003-03-06 | Walton Jay R. | Method and apparatus for processing data for transmission in a multi-channel communication system using selective channel transmission |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102420639A (en) * | 2011-10-19 | 2012-04-18 | 南京致德软件科技有限公司 | Low voltage power line high-frequency noise sampling and replaying system |
CN102420639B (en) * | 2011-10-19 | 2014-06-18 | 南京致德软件科技有限公司 | Low voltage power line high-frequency noise sampling and replaying system |
Also Published As
Publication number | Publication date |
---|---|
CN101714968B (en) | 2013-10-09 |
JP2005057644A (en) | 2005-03-03 |
ES2541682T3 (en) | 2015-07-23 |
EP1654849B1 (en) | 2015-04-22 |
CN102118347B (en) | 2013-12-25 |
US20080095253A1 (en) | 2008-04-24 |
US8086194B2 (en) | 2011-12-27 |
EP1654849A1 (en) | 2006-05-10 |
EP2293508A1 (en) | 2011-03-09 |
US7725081B2 (en) | 2010-05-25 |
US20050037722A1 (en) | 2005-02-17 |
CN101714968A (en) | 2010-05-26 |
US7302240B2 (en) | 2007-11-27 |
CN102118347A (en) | 2011-07-06 |
JP4356392B2 (en) | 2009-11-04 |
CN1833421A (en) | 2006-09-13 |
ES2539580T3 (en) | 2015-07-02 |
EP2293508B1 (en) | 2015-04-15 |
US20100226446A1 (en) | 2010-09-09 |
CN1833421B (en) | 2012-07-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1654849B1 (en) | Multi-carrier communication apparatus with adaptive transmission according to transmission path fluctuations | |
EP1488590B1 (en) | A multiple channel wireless receiver | |
EP1689077B1 (en) | Automatic gain control apparatus and method in an orthogonal frequency division multiple access system | |
US7366088B2 (en) | Method and orthogonal frequency division multiplexing (OFDM) receiver for reducing the influence of harmonic interference on OFDM transmission systems | |
US20040228417A1 (en) | Communication system with adaptive channel correction | |
JP2005057644A5 (en) | ||
EP1890397B1 (en) | Transmitter/receiver and method for communicating with a remote transmitter/receiver using spatial phase codes | |
CN101133579A (en) | OFDM communication system and OFDM communication method | |
JP2000269919A (en) | Ofdm communication unit | |
EP1579596B1 (en) | Sub-carriers transmission power control | |
EP2730034B1 (en) | Power line communication modem, power line communication system and power line communication method | |
EP1435713B1 (en) | Adaptive cancellation of inter-carrier interference | |
US7542513B2 (en) | Communication data using wideband communications | |
JP5254526B2 (en) | System, modem, receiver, transmitter and method for improving transmission performance | |
JP4766157B2 (en) | Communication device | |
JP2012506188A (en) | Telecommunications method and system | |
CA2469913A1 (en) | Method and apparatus for multi-carrier transmission | |
US7149252B2 (en) | Communicating data using wideband communications | |
KR20120033761A (en) | Method for estimating snr(signal to noise ratio) in wireless communication system | |
KR0151035B1 (en) | Multi-carrier radio communication system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200480022652.X Country of ref document: CN |
|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2004771624 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 460/CHENP/2006 Country of ref document: IN Ref document number: 460CHENP/2006 Country of ref document: IN |
|
WWP | Wipo information: published in national office |
Ref document number: 2004771624 Country of ref document: EP |