CN101309241B - All-pass time reversal ultra-wideband wireless communication method and system - Google Patents
All-pass time reversal ultra-wideband wireless communication method and system Download PDFInfo
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Abstract
The invention provides an all-pass balanced time-reversal ultra-wide band (UWB) wireless communication method and system used for restraining the coherent multi-path effect in the UWB wireless communication system and improving the transmission performance of the communication system which belongs to the wireless communication technical field. The shock response Hc(omega)=|Hc(omega)| *e<jtheta(omega)> of a wireless channel is measured firstly; and then a all-pass balanced factor H2(omega)=1/|Hc(omega)|<2> and a time-reversal factor H1(omega)=|Hc(omega)|*e<-jtheta(omega)> of the wireless channel are constructed respectively; finally, the all-pass balanced factor H2 (omega) and the time-reversal factor H1 (omega) are used for the all-pass balanced time-reversal processing to the wireless channel, so that a transmission function of the wireless channel after the all-pass balanced time-reversal processing is H'c(omega)=H2(omega)*H1(omega)*Hc(omega)=1. The invention adopts the all-pass balanced factor H2(omega)=1/|Hc(omega)|<2> to process all-pass balancing to the time-reversal wireless channel, enables the wireless channel processed by the all-pass balanced time-reversal processing to be equivalent to an all-pass channel and eliminates the coherent multi-path effect (namely frequency selective fading) in the ultra-wide band wireless communication channel. The all-pass balanced time-reversal ultra-wide band wireless communication method has the advantages of simple operation, lower computation burden and being applicable to the wireless communication systems with different communication schemes.
Description
Technical field
The invention belongs to wireless communication technology field, relate to time reversal (TR, Time Reversal) wireless communication technology.
Background technology
TR (TR, Time Reversal) is a kind of novel multipath fading inhibition technology of development in recent years.Different with traditional multipath fading technology, TR has unique Space Time focusing function and natural environment self-adaption.TR can adapt to the wireless transmission environment of various complexity automatically, does not need complicated multipath signal to merge and handles and adaptive algorithm, greatly simplified receiver design; What is more important, TR can utilize multipath energy to improve signal to noise ratio, compression pulse expansion fully, reduces intersymbol interference, improve the message capacity of system when suppressing multipath fading.A large amount of theory and experimental studies show that in the environment that multipath enriches, the room and time focusing effect of pure TR technology (PTR, Pure Time Reversal) is apparent in view, and are very remarkable to the effect that improves performance in wireless communication systems.
Yet, experimental studies have found that TR is unsatisfactory to the inhibition effect of relevant multipath (being frequency selective fading) effect in ultra broadband (UWB, the Ultra Wide Band) wireless channel, especially under sparse multi-path environment, still there is the very strong relevant multipath pulse of amplitude.These relevant multipath pulses can overlap mutually under high rate data transmission with signal pulse, produces serious intersymbol interference (ISI), and then develop on the restriction wireless communication system two-forty, high-performance direction.
In order to address the above problem, many research workers have proposed the multiple technologies solution, for example based on the TR Radio Transmission Technology of lowest mean square root error equilibrium (MMSE), force the TR transmission of make zero (ZF) etc.These technology all are that various balancing techniques are combined with the TR technology, eliminate relevant multipath in the UWB wireless communication system to arrive, and suppress the purpose of ISI in the wireless channel.But from present technical research state, the algorithm of existing TR balancing technique is all very complicated, operand is big, realize that difficulty is big, and inconvenience is applied among the wireless transmission communication system at a high speed.
For example, document " Improvement of Time-Reversal Communications Using Adaptive Channel Equalizers " (IEEE Journal Of Oceanic Engineering, Vol.31, No.2, April 2006) a kind of TR wireless communication transmissions scheme of proposition based on adaptive channel equalizer.This scheme adopts TR precompensation technology at transmitting terminal, at receiving terminal to received signal at first through a prefilter, and then by the effect of a DFF of forming by decision device and feedback filter (DFE) with the arrival equalizing signal.The weight parameter of the filter that wherein whole receiving terminal is used all is to adopt lowest mean square root error (MMSE) technology to be optimized design.By time reversal and lowest mean square root error balancing technique combination of them are suppressed multipath effect, eliminate the relevant multipath in the channel, theoretical research shows that this method can effectively reduce the ISI that multipath effect causes, and improves the transmission performance of TR wireless communication system.But along with the increase of the transmission path quantity in the wireless channel, it is very complicated that the receiver structure of this system will become, and equalization algorithm also can sharply increase required operation time, and hardware realizes that difficulty is big, the complexity height.Simultaneously, because the required operand of algorithm is big, so be difficult to be applied to the high-speed radio transmission system.
Document " Time Reversal and Zero-Forcing Equal ization for Fixed Wireless Access Channels " (Signals, Systems and Computers, 2005.Conference Record of the Thirty-Ninth Asilomar Conference, p.1297-1301, Oct28-Nov1,2005) will force the pre-equalization techniques that makes zero to combine with TR.This technology is after having determined channel impulse response, utilize the known response function to utilize finite impulse response (FIR) digital filter to simulate whole transmission channel the fixed wireless transmission channel, utilize then and will force make zero algorithm and the time reversal technology purpose that goes out the waveform generator that is complementary with wireless channel with the arrival equalization channel designed in conjunction.Whole channel is carried out the amplitude equalization notional result to be shown, this technology is better than PTR and the pure balancing technique that makes zero of forcing in the inhibition to multipath, but, this system needs complicated channel estimation method, waveform generator is carried out complicated the most optimized parameter design and strict time synchronized, so be not easy to Project Realization.
Balancing technique is to suppress a kind of effective technology of relevant multipath and non-coherent multi pathway, but above-mentioned lowest mean square root error with force the balancing technique difficulty on structure and Project Realization that makes zero big, the equalization algorithm complexity, operand also sharply increases with the increase of propagation path quantity, is difficult to be used widely in high-speed radiocommunication system.
Summary of the invention
The invention provides the time reversal ultra-broadband wireless communication method of all-pass equilibrium,, improve the transmission performance of communication system in order to suppress the relevant multipath effect in the UWB wireless communication system.Entire method has simple to operate, the characteristics that operand is little.
Technical solution of the present invention is:
The time reversal ultra-broadband wireless communication method of all-pass equilibrium as shown in Figure 1, may further comprise the steps:
The impulse response h of step 1, measurement wireless channel
c(t) or H
c(ω): regard wireless channel as a both-end passive device, from an input of wireless channel one end (transmitting terminal or receiving terminal) emission detectable signal q (t), the output detectable signal q ' of the measurement wireless channel other end (receiving terminal or transmitting terminal) (t), by the wireless channel transmission theory, can import detectable signal q (t), output detectable signal q ' (t) and the impulse response h of wireless channel
c(t) pass of time domain and frequency domain is between the three:
In the following formula,
Represent convolution algorithm.Utilize signal processor butt joint following formula to carry out the frequency domain conversion of being divided by then and promptly obtain the impulse response H of wireless channel
c(ω), and the impulse response H of channel
c(ω) have following expression-form:
H
c(ω)＝|H
c(ω)｜·e
jθ(ω)
In the following formula, | H
c(ω) | be the frequency domain gain or the fissipation factor of wireless channel, e
J θ (ω)The phase factor or the chromatic dispersion factor for wireless channel.
Step 2, according to the impulse response H of the wireless channel of step 1 gained
c(ω)=| H
c(ω) | e
J θ (ω), the all-pass balance factor H of structure wireless channel
2(ω)=1/|H
c(ω) |
2
Step 3, according to the impulse response H of the wireless channel of step 1 gained
c(ω)=| H
c(ω) | e
J θ (ω), the time reversal factor H of structure wireless channel
1(ω)=| H
c(ω) | e
-j θ (ω)
Step 4, utilize the all-pass balance factor H of the wireless channel of step 2 gained
2(ω)=1/|H
c(ω) |
2Time reversal factor H with the wireless channel of step 3 gained
1(ω)=| H
c(ω) | e
-j θ (ω), wireless channel is carried out the time reversal of all-pass equilibrium and handles, the transfer function H ' of the wireless channel after feasible time reversal through the all-pass equilibrium is handled
c(ω)=H
2(ω) H
1(ω) H
c(ω)=1/|H
c(ω) |
2| H
c(ω) | e
-j θ (ω)| H
c(ω) | e
J θ (ω)=1.
By technique scheme as can be seen: if in conventional time reversal communication process, increase an all-pass equalization step, promptly adopt an all-pass balance factor H
2(ω)=1/|H
c(ω) |
2Wireless channel to time reversal carries out the all-pass equilibrium, and the wireless channel after then whole time reversal through the all-pass equilibrium is handled can equivalence be an all-pass channel, just means also that thus the change of amplitude and phase place can not take place in transmission course signal.Time reversal and all-pass equilibrium are benefited from the realization of all-pass channel, wherein, and time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)Frequency domain phase place complex conjugate characteristic offset wireless channel impulse response H
c(ω)=| H
c(ω) | e
J θ (ω)Phase factor e
J θ (ω), and all-pass balance factor H
2(ω)=1/|H
c(ω) |
2Then eliminated the frequency in the wireless channel and become decay | H
c(ω) |, i.e. frequency selective fading.
The time reversal super broad band radio communication system of all-pass equilibrium comprises transmitter, receiver and wireless channel; Described transmitter comprises information source, encoder, modulator and transmitting antenna, and described receiver comprises reception antenna, demodulator and decoder; Described wireless channel transfer function is H
c(ω)=| H
c(ω) | e
J θ (ω), wherein | H
c(ω) | be the frequency domain gain or the fissipation factor of wireless channel, e
J θ (ω)The phase factor or the chromatic dispersion factor for wireless channel; Also comprise an all-pass equalizer and a time reversal device, the transfer function of described all-pass equalizer is H
2(ω)=1/|H
c(ω) |
2, the transfer function of described time reversal device is H
1(ω)=| H
c(ω) | e
-j θ (ω)All-pass wireless channel of the common formation of described all-pass equalizer, time reversal device and wireless channel three, the transfer function of all-pass wireless channel is 1.
Described all-pass equalizer is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the all-pass equalizing signal 1/|H of memory stores
c(ω) |
2Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver.
Described time reversal device is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the time reversal signal of memory stores | H
c(ω) | e
-j θ (ω)Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver.
Also comprise a wireless channel test channel, signaling transmitter module, transmitter signaling receiver module and signal processing module by receiver are formed, the signaling-information q (t) that the signaling transmitter module of receiver sends transfers to transmitter through reception antenna, wireless channel, transmitter signaling receiver module by transmitting antenna receive signaling response signal q ' (t) after, measure wireless channel transfer function H by signal processing module
c(ω)=| H
c(ω) | e
J θ (ω)And convert corresponding all-pass equalizing signal 1/|H to
c(ω) |
2With the time reversal signal | H
c(ω) | e
-j θ (ω), then with all-pass equalizing signal 1/|H
c(ω) |
2Import the memory of described all-pass equalizer, with the time reversal signal | H
c(ω) | e
-j θ (ω)Import the memory of described time reversal device.
Source signal x (t) is by the input two of the time domain acoustic convolver of described all-pass equalizer and the all-pass equalizing signal 1/|H of described all-pass equalizer
c(ω) |
2The phase convolution, the signal after the convolution is by the input two of the time domain acoustic convolver of described time reversal device and the time reversal signal of described time reversal device | H
c(ω) | e
-j θ (ω)The phase convolution after the encoded device coding of the signal after the convolution, the modulators modulate, is gone out by the transmission antennas transmit of transmitter more again; The reception antenna of receiver receives signal after restore source signal x (t) after the demodulator demodulation, decoder decode.
The time reversal super broad band radio communication system of all-pass equilibrium comprises transmitter, receiver and wireless channel; Described transmitter comprises information source, encoder, modulator and transmitting antenna, and described receiver comprises reception antenna, demodulator and decoder; Described wireless channel transfer function is H
c(ω)=| H
c(ω) | e
J θ (ω), wherein | H
c(ω) | be the frequency domain gain or the fissipation factor of wireless channel, e
J θ (ω)The phase factor or the chromatic dispersion factor for wireless channel; Also comprise an all-pass equalizer and a time reversal device, the transfer function of described all-pass equalizer is H
2(ω)=1/|H
c(ω) |
2, the transfer function of described time reversal device is H
1(ω)=| H
c(ω) | e
-j θ (ω)All-pass wireless channel of the common formation of described all-pass equalizer, time reversal device and wireless channel three, the transfer function of all-pass wireless channel is 1.
Described all-pass equalizer is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the all-pass equalizing signal 1/|H of memory stores
c(ω) |
2Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver.
Described time reversal device is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the time reversal signal of memory stores | H
c(ω) | e
-j θ (ω)Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver.
Also comprise a wireless channel test channel, signaling transmitter module, transmitter signaling receiver module and signal processing module by receiver are formed, the signaling-information q (t) that the signaling transmitter module of receiver sends transfers to transmitter through reception antenna, wireless channel, transmitter signaling receiver module by transmitting antenna receive signaling response signal q ' (t) after, measure wireless channel transfer function H by signal processing module
c(ω)=| H
c(ω) | e
J θ (ω)And convert corresponding all-pass equalizing signal 1/|H to
c(ω) |
2With the time reversal signal | H
c(ω) | e
-j θ (ω), then with all-pass equalizing signal 1/|H
c(ω) |
2Import the memory of described all-pass equalizer, with the time reversal signal | H
c(ω) | e
-j θ (ω)Import the memory of described time reversal device.
Source signal x (t) is by the input two of the time domain acoustic convolver of described time reversal device and the time reversal signal of described time reversal device | H
c(ω) | e
-j θ (ω)The phase convolution, the signal after the convolution is by the input two of the time domain acoustic convolver of described all-pass equalizer and the all-pass equalizing signal 1/|H of described all-pass equalizer
c(ω) |
2The phase convolution after the encoded device coding of the signal after the convolution, the modulators modulate, is gone out by the transmission antennas transmit of transmitter more again; The reception antenna of receiver receives signal after restore source signal x (t) after the demodulator demodulation, decoder decode.
The invention has the beneficial effects as follows:
(1) the present invention only increases an all-pass equalization step and a time reversal step on the general communication method, just can effectively suppress multipath effect, has overcome the traditional communication method and need adopt the multichannel equalizer to carry out the deficiency of channel equalization.
(2) the all-pass balance factor of the present invention inverse that is conventional wireless channel power spectral density only needs to extract the amplitude information of channel impulse response, has reduced the extraction difficulty to channel impulse response.
(3) the present invention only needs wireless channel impulse response once measure, and need not a large amount of channel test data and complicated channel extraction algorithm, has reduced operand and channel extraction time.
(4) the present invention can effectively solve multidiameter and the frequency selective fading in the UWB wireless channel, suppress intersymbol interference, improve the communication system transmits performance, can be applicable to the wireless communication system of different communication system, as OFDM, MIMO, UWB wireless communication system etc.;
(5) the present invention can be according to the variation immediate updating all-pass balance factor and the time reversal factor of channel, and the environment self-adaption ability is strong, can be applicable to the information wireless transmission in the complex environment such as wireless sensor network.
(6) all-pass compensation method of the present invention is not limited to carrierfree UWB communication system, also can be applicable to carrier wave UWB wireless transmitting system, can also be applied to other wireless communication system simultaneously.
Description of drawings
Fig. 1 is a basic procedure schematic diagram of the present invention.
Fig. 2 is one of specific embodiment of the invention schematic diagram.
Fig. 3 is two of a specific embodiment of the invention schematic diagram.
Fig. 4 is three of a specific embodiment of the invention schematic diagram.
Fig. 5 is four of a specific embodiment of the invention schematic diagram.
Fig. 6 is five of a specific embodiment of the invention schematic diagram.
Fig. 7 is six of a specific embodiment of the invention schematic diagram.
Embodiment
Technical solutions according to the invention are wherein utilized the all-pass balance factor H of the wireless channel of step 2 gained in the step 4
2(ω)=1/|H
c(ω) |
2Time reversal factor H with the wireless channel of step 3 gained
1(ω)=| H
c(ω) | e
-j θ (ω), wireless channel is carried out the time reversal of all-pass equilibrium and handle, both can carry out at transmitting terminal, also can carry out, even can carry out the balanced and time reversal processing of all-pass at transmitting terminal and receiving terminal respectively at receiving terminal.
Embodiment one:
Utilize the all-pass balance factor H of the wireless channel of step 2 gained in the step 4
2(ω)=1/|H
c(ω) |
2Time reversal factor H with the wireless channel of step 3 gained
1(ω)=| H
c(ω) | e
-j θ (ω), wireless channel being carried out the time reversal processing of all-pass equilibrium and carry out at transmitting terminal, concrete grammar is as follows:
As shown in Figure 2, establishing source signal is x (ω), successively source signal x (ω) is carried out the time reversal processing of all-pass equilibrium, is about to source signal x (ω) and all-pass balance factor H
2(ω)=1/|H
c(ω) |
2With time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)Carry out convolution algorithm successively, signal x (ω) 1/|H that obtains
c(ω) |
2| H
c(ω) | e
-j θ (ω)After the wireless channel transmission, obtain signal x (ω) 1/|H
c(ω) |
2| H
c(ω) | e
-j θ (ω)| H
c(ω) | e
J θ (ω)=x (ω).
In the such scheme, source signal x (ω) is carried out the time reversal of all-pass equilibrium and handle, also can be with source signal x (ω) and time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)With all-pass balance factor H
2(ω)=1/|H
c(ω) |
2Carry out convolution algorithm successively, the signal x (ω) that obtains | H
c(ω) | e
-j θ (ω)1/|H
c(ω) |
2After the wireless channel transmission, obtain signal x (ω) | H
c(ω) | e
-j θ (ω)1/|H
c(ω) |
2| H
c(ω) | e
J θ (ω)=x (ω), as shown in Figure 3.
Embodiment two:
Utilize the all-pass balance factor H of the wireless channel of step 2 gained in the step 4
2(ω)=1/|H
c(ω) |
2Time reversal factor H with the wireless channel of step 3 gained
1(ω)=| H
c(ω) | e
-j θ (ω), wireless channel being carried out the time reversal processing of all-pass equilibrium and carry out at receiving terminal, concrete grammar is as follows:
As shown in Figure 4, establishing source signal is x (ω), and the signal that the receiving terminal antenna receives is y (ω)=x (ω) | H
c(ω) | e
J θ (ω), with signal y (ω) and all-pass balance factor H
2(ω)=1/|H
c(ω) |
2With time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)Carry out convolution algorithm successively, obtain signal y (ω) 1/|H
c(ω) |
2| H
c(ω) | e
-j θ (ω)=x (ω).
In the such scheme, the signal that the receiving end antenna is received is the time reversal processing that y (ω) carries out the all-pass equilibrium, and also the signal that the receiving end antenna can be received be y (ω) and time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)With all-pass balance factor H
2(ω)=1/|H
c(ω) |
2Carry out convolution algorithm successively, the signal y (ω) that obtains | H
c(ω) | e
-j θ (ω)1/|H
c(ω) |
2=x (ω), as shown in Figure 5.
Embodiment three:
Utilize the all-pass balance factor H of the wireless channel of step 2 gained in the step 4
2(ω)=1/|H
c(ω) |
2Time reversal factor H with the wireless channel of step 3 gained
1(ω)=| H
c(ω) | e
-j θ (ω), wireless channel being carried out the time reversal processing of all-pass equilibrium and carry out respectively at transmitting terminal and receiving terminal, concrete grammar is as follows:
As shown in Figure 6, establishing source signal is x (ω), and source signal x (ω) is carried out the all-pass equilibrium treatment, is about to source signal x (ω) and all-pass balance factor H
2(ω)=1/|H
c(ω) |
2Carry out convolution algorithm, signal x (ω) 1/|H that obtains
c(ω) |
2After the wireless channel transmission, obtain signal x (ω) 1/|H
c(ω) |
2| H
c(ω) | e
J θ (ω)Again with signal x (ω) 1/|H
c(ω) |
2| H
c(ω) | e
J θ (ω)With time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)Carry out convolution algorithm, obtain signal x (ω) 1/|H
c(ω) |
2| H
c(ω) | e
J θ (ω)| H
c(ω) | e
-j θ (ω)=x (ω).
Embodiment four:
Utilize the all-pass balance factor H of the wireless channel of step 2 gained in the step 4
2(ω)=1/|H
c(ω) |
2Time reversal factor H with the wireless channel of step 3 gained
1(ω)=| H
c(ω) | e
-j θ (ω), wireless channel being carried out the time reversal processing of all-pass equilibrium and carry out respectively at transmitting terminal and receiving terminal, concrete grammar is as follows:
As shown in Figure 7, establishing source signal is x (ω), source signal x (ω) is carried out time reversal handle, and is about to source signal x (ω) and time reversal factor H
1(ω)=| H
c(ω) | e
-j θ (ω)Carry out convolution algorithm, the signal x (ω) that obtains | H
c(ω) | e
-j θ (ω)After the wireless channel transmission, obtain signal x (ω) | H
c(ω) | e
-j θ (ω)| H
c(ω) | e
J θ (ω)Again with signal x (ω) | H
c(ω) | e
-j θ (ω)| H
c(ω) | e
J θ (ω)With all-pass balance factor H
2(ω)=1/|H
c(ω) |
2Carry out convolution algorithm, obtain signal x (ω) | H
c(ω) | e
-j θ (ω)| H
c(ω) | e
J θ (ω)1/|H
c(ω) |
2=x (ω).
Need to prove that the present invention does not consider the coding and the modulated process of transmitting terminal, also do not consider the demodulation sign indicating number process of receiving terminal.If they are completely taken into account, the present invention also has more execution mode, such as: before transmitting terminal coding or before the modulation of coding back or carry out the time reversal processing of all-pass equilibrium after the modulation; Before the receiving terminal demodulation or after the demodulation before the decoding or the time reversal of carrying out the all-pass equilibrium after the decoding handle or the like.All execution modes all can not change an essence, promptly conventional wireless channel are carried out the balanced and time reversal processing of all-pass, conventional wireless channel " transformation " is become a wireless channel all-pass, time reversal, thereby eliminate multipath effect.
Claims (2)
1. the time reversal super broad band radio communication system of all-pass equilibrium comprises transmitter, receiver and wireless channel; Described transmitter comprises information source, encoder, modulator and transmitting antenna, and described receiver comprises reception antenna, demodulator and decoder; Described wireless channel transfer function is H
c(ω)=| H
c(ω) | e
J θ (ω), wherein | H
c(ω) | be the frequency domain gain or the fissipation factor of wireless channel, e
J θ (ω)The phase factor or the chromatic dispersion factor for wireless channel; Also comprise an all-pass equalizer and a time reversal device, the transfer function of described all-pass equalizer is H
2(ω)=1/|H
c(ω) |
2, the transfer function of described time reversal device is H
1(ω)=| H
c(ω) | e
-j θ (ω)All-pass wireless channel of the common formation of described all-pass equalizer, time reversal device and wireless channel three, the transfer function of all-pass wireless channel is 1;
Described all-pass equalizer is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the all-pass equalizing signal 1/|H of memory stores
c(ω) |
2Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver;
Described time reversal device is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the time reversal signal of memory stores | H
c(ω) | e
-j θ (ω)Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver;
Also comprise a wireless channel test channel, signaling transmitter module, transmitter signaling receiver module and signal processing module by receiver are formed, the signaling-information q (t) that the signaling transmitter module of receiver sends transfers to transmitter through reception antenna, wireless channel, transmitter signaling receiver module by transmitting antenna receive signaling response signal q ' (t) after, measure wireless channel transfer function H by signal processing module
c(ω)=| H
c(ω) | e
J θ (ω)And convert corresponding all-pass equalizing signal 1/|H to
c(ω) |
2With the time reversal signal | H
c(ω) | e
-j θ (ω), then with all-pass equalizing signal 1/|H
c(ω) |
2Import the memory of described all-pass equalizer, with the time reversal signal | H
c(ω) | e
-j θ (ω)Import the memory of described time reversal device;
Source signal x (t) is by the input two of the time domain acoustic convolver of described all-pass equalizer and the all-pass equalizing signal 1/|H of described all-pass equalizer
c(ω) |
2The phase convolution, the signal after the convolution is by the input two of the time domain acoustic convolver of described time reversal device and the time reversal signal of described time reversal device | H
c(ω) | e
-j θ (ω)The phase convolution after the encoded device coding of the signal after the convolution, the modulators modulate, is gone out by the transmission antennas transmit of transmitter more again; The reception antenna of receiver receives signal after restore source signal x (t) after the demodulator demodulation, decoder decode.
2. the time reversal super broad band radio communication system of all-pass equilibrium comprises transmitter, receiver and wireless channel; Described transmitter comprises information source, encoder, modulator and transmitting antenna, and described receiver comprises reception antenna, demodulator and decoder; Described wireless channel transfer function is H
c(ω)=| H
c(ω) | e
J θ (ω), wherein | H
c(ω) | be the frequency domain gain or the fissipation factor of wireless channel, e
J θ (ω)The phase factor or the chromatic dispersion factor for wireless channel; Also comprise an all-pass equalizer and a time reversal device, the transfer function of described all-pass equalizer is H
2(ω)=1/|H
c(ω) |
2, the transfer function of described time reversal device is H
1(ω)=| H
c(ω) | e
-j θ (ω)All-pass wireless channel of the common formation of described all-pass equalizer, time reversal device and wireless channel three, the transfer function of all-pass wireless channel is 1;
Described all-pass equalizer is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the all-pass equalizing signal 1/|H of memory stores
c(ω) |
2Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver;
Described time reversal device is made of memory, FILLO controller, D/A converter and time domain acoustic convolver, the time reversal signal of memory stores | H
c(ω) | e
-j θ (ω)Export through the control of FILLO controller, and after D/A converter converts analog signal to, pass through input one input of time domain acoustic convolver;
Also comprise a wireless channel test channel, signaling transmitter module, transmitter signaling receiver module and signal processing module by receiver are formed, the signaling-information q (t) that the signaling transmitter module of receiver sends transfers to transmitter through reception antenna, wireless channel, transmitter signaling receiver module by transmitting antenna receive signaling response signal q ' (t) after, measure wireless channel transfer function H by signal processing module
c(ω)=| H
c(ω) | e
J θ (ω)And convert corresponding all-pass equalizing signal 1/|H to
c(ω) |
2With the time reversal signal | H
c(ω) | e
-j θ (ω), then with all-pass equalizing signal 1/|H
c(ω) |
2Import the memory of described all-pass equalizer, with the time reversal signal | H
c(ω) | e
-j θ (ω)Import the memory of described time reversal device;
Source signal x (t) is by the input two of the time domain acoustic convolver of described time reversal device and the time reversal signal of described time reversal device | H
c(ω) | e
-j θ (ω)The phase convolution, the signal after the convolution is by the input two of the time domain acoustic convolver of described all-pass equalizer and the all-pass equalizing signal 1/|H of described all-pass equalizer
c(ω) |
2The phase convolution after the encoded device coding of the signal after the convolution, the modulators modulate, is gone out by the transmission antennas transmit of transmitter more again; The reception antenna of receiver receives signal after restore source signal x (t) after the demodulator demodulation, decoder decode.
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| CN102005828B (en) * | 2010-11-30 | 2012-09-12 | 电子科技大学 | Wireless sensor network node wireless charging system and method based on time reversal |
| CN102158858B (en) * | 2011-05-27 | 2013-10-02 | 中国人民解放军信息工程大学 | Method and device for encrypting MMSE (minimum mean square error) pre-equalization wireless channel based on multipath redundancy |
| CN102332937B (en) * | 2011-09-23 | 2013-12-11 | 电子科技大学 | OPPM-UWB (overlapping pulse position modulation-ultra wide band) communication method on basis of time reversal technology |
| CN103763225B (en) * | 2013-11-28 | 2017-01-18 | 电子信息系统复杂电磁环境效应国家重点实验室 | Signal processing device and method based on time reversal |
| CN104639491B (en) * | 2015-01-29 | 2017-11-14 | 武汉铭为电子科技有限公司 | A kind of time reversal orthogonal frequency division multiplexing radio communication method based on SFME |
| CN104717173B (en) * | 2015-03-16 | 2018-01-12 | 电子科技大学 | Sub-carriers complex balancing wireless communication method based on channel decoupling |
| CN105827288B (en) * | 2016-03-11 | 2019-04-05 | 电子科技大学 | A kind of 2D-SPM digital radio communication method focused based on time reversal electromagnetic wave dot matrix |
| CN110515052B (en) * | 2019-06-18 | 2021-07-16 | 西安电子科技大学 | Ultra-wideband frequency domain unequal interval sampling target detection method based on time reversal |
| CN113904705B (en) * | 2021-09-30 | 2024-03-15 | 广州又一信息科技有限公司 | Method for improving anti-interference of multi-input multi-output ultra wideband system |
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