CN1750432B - Antenna direction regulating method and OFDM receiving device - Google Patents
Antenna direction regulating method and OFDM receiving device Download PDFInfo
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- CN1750432B CN1750432B CN2005100992949A CN200510099294A CN1750432B CN 1750432 B CN1750432 B CN 1750432B CN 2005100992949 A CN2005100992949 A CN 2005100992949A CN 200510099294 A CN200510099294 A CN 200510099294A CN 1750432 B CN1750432 B CN 1750432B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/02—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical movement of antenna or antenna system as a whole
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/22—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the orientation in accordance with variation of frequency of radiated wave
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
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- Radio Transmission System (AREA)
- Circuits Of Receivers In General (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
Abstract
The invention provides a signal transmission system. After a transmitting device moves and passes a set time, whether a primary fresnel region is contacted with an elevation sectional view or not is predicted, if so, a display indicating a notice is performed. While displaying the elevation sectional view between a position of the transmitting device and a position of a rotary antenna, a direct wave of a signal transmitted by the transmitting device between the two positions and the primary fresnel region, after the transmitting device moves and passes the set time, whether the primary fresnel region is contacted with the elevation sectional view or not is predicted, if so, a risk factor indicating a notice is displayed.
Description
Technical field
The present invention relates to the direction adjustment of the reception antenna in the transmitting device of a kind of use Orthodoxy Frequency Division Multiplex mode (Orthogonal FrequencyDivision Multiplexing: following note is made the OFDM mode).
Background technology
In recent years, in the wireless device field, as the stronger modulation system of anti-multipath decline, the OFDM mode is noticeable, is carrying out a large amount of application studies with the various countries headed by Europe and the Japan.Wherein, with regard to the exploitation trend and mode of the received terrestrial digital broadcasting of UHF frequency band, write up in non-patent literature 1 for example.
This OFDM mode adopt with the image at relaying scene be wirelessly transmitted to TV station FPU (FieldPickup Unit: the transmission means field pickup unit), be used for fixing or the mobile wireless relaying in.
In the former antenna direction regulating method, take following method, promptly utilize the wave detector of receiver side to detect the reception electric field level, search receives electric field level and becomes maximum direction, adjusts the direction of antenna.But if receive the electric field step-down, then received signal can be embedded in the noise, is difficult to high Precision Detection.That is, because in the starting stage of direction adjustments of antenna, it is very low to receive electric field, so even if the arrival of faint ofdm signal can not be caught the received signal of imbedding in the noise, can only be by manually groping the travel direction adjustment.
Therefore, the applicant proposes to improve the antenna direction regulating method (for example patent documentation 1) of these shortcomings.Below, come simple declaration with Fig. 3.
Utilization is transformed into error correcting code, is modulated to the preliminary treatment of 64QAM etc., the information code that is input to the transmission pre-process circuit 13a of dispensing device 12 is transformed to the train of signal of frequency distribution image of the signal of each carrier wave of expression, is transformed to the train of signal of express time waveform by inverse Fourier transform (IFFT) circuit 13b.Afterwards, for the influence of the intersymbol interference that reduces the receiver side that causes by the delay ripple in the transmission path, insert circuit 13c to the additional guide interval of the ofdm signal that sends in guide interval.The signal that has inserted this guide interval further is implemented reprocessings such as orthogonal transform, D/A conversion, up conversion in treatment circuit 13d, send from transmitting antenna 11.
The OFDM transmission signals that this sends out is received antenna 21 and receives, and sends to demodulating equipment 22 by cable.The received signal that is input to demodulating equipment 22 is input to by FFT (Fourier transform) the circuit 23c, transmission path response equalizing circuit 23d, the Xie Tiao ﹠amp that implement the signal transmitted sign indicating number is carried out the signal processing of demodulation after the complex vector located signal that is transformed to numeral by down converter 23a, A/D translation circuit 23b; The path of the principal series that decoding circuit 23e etc. constitute simultaneously, is input to the relevant circuit 24 of calculating of the guiding that is positioned at other path.
Afterwards, guiding is relevant calculates the related operation of circuit 24 in carrying out during the guiding of received signals, will guide coherent signal to output to incoming level and calculate circuit 25.Incoming level is calculated circuit 25 according to the guiding coherent signal, and the level of calculating received signal outputs to direction and adjusts signal generating circuit 26.
Direction is adjusted signal generating circuit 26 according to the received signal level of calculating, and generates the direction adjustment signal of reception antenna 21, and uses the direction adjustment signal that generates, and carries out the direction adjustment of reception antenna 21.
Non-patent literature 1: image information medium association will Vol.52 in 1998, No.11
Patent documentation 1: Japanese patent laid-open 2003-115787 communique
The former wave detector that utilizes receiver side detects and receives electric field level, search reception electric field level becomes in the antenna direction regulating method of maximum direction, if receive the electric field step-down, then received signal can be embedded in the noise, is difficult to high Precision Detection.For example, be the noise figure of 17MHz, primary amplifier when being 4dB receiving electric field for-90dBm, frequency domain width, CN is than for about-7dB, is difficult to detect receive electric field and be lower than-received signal of the such level of 90dBm.In addition, even if use the antenna direction regulating method of Fig. 3, also be difficult to detect and receive electric field and be significantly less than-received signal of the such level of 90dBm.
That is, because in the starting stage of the direction adjustment of antenna, it is very low to receive electric field, thus even if the ofdm signal of trace arrives, can not catch the received signal of imbedding in the noise, can only be by manually groping the travel direction adjustment.
Summary of the invention
The present invention is in order to solve above-mentioned problem, in the receiving system of the transmitting device of the ofdm signal during transmission comprises guide interval, the above-mentioned ofdm signal that execution receives, with complex multiplication to the signal of length delay during this ofdm signal execution significant character, at least the signal during the guide interval of the resulting complex multiplication signal of the result of this complex multiplication is carried out equalization to be handled, handle handle the signal execution signed magnitude arithmetic(al) that obtains by above-mentioned equalization corresponding to receiving electric field level, according to the resulting signal level of the result of this signed magnitude arithmetic(al), generate the direction adjustment signal of reception antenna, and use the direction adjustment of this generation to carry out the direction adjustment of reception antenna with signal.
In addition, handle handle the signal execution signed magnitude arithmetic(al) that obtains by equalization corresponding to receiving electric field level, according to the resulting signal level of the result of this signed magnitude arithmetic(al), the direction that generates reception antenna is adjusted signal, and uses the direction adjustment signal of this generation to carry out the direction adjustment of reception antenna.As above-mentioned signed magnitude arithmetic(al), calculate in following at least:, calculate square proportional reception electric field signal R1 with received power by the quadratic sum of computing I component and Q component; By square root sum square of computing I component and Q component, calculate and the proportional reception electric field signal of received power R2.
In addition, the direction adjustment that changes one of at least at interval with voice signal or color, brightness, flicker of the direction adjustment that changes one of at least at interval of the continuation that the direction adjustment that generates is made as level corresponding to received signal, tonequality, volume, sound with signal is with light signal or show arbitrary at least signal in numerical value, character, the curve signal one of at least.
In addition, a kind of transmission comprises the OFDM receiving system of the transmitting device of the ofdm signal during the guide interval, by possessing the complex multiplication operation parts, carry out the above-mentioned ofdm signal that receives, with the complex multiplication of this ofdm signal being carried out the signal of length delay during significant character; With the filtering operation parts, at least the signal during the guide interval of the resulting complex multiplication signal of the result of this complex multiplication is carried out the low-pass filtering computing, have the direction adjustment and generate parts with signal, this direction adjustment generates parts with signal the signal that is obtained by above-mentioned filtering operation is carried out the signed magnitude arithmetic(al) processing, according to the resulting signal level of the result of this signed magnitude arithmetic(al), generate the direction adjustment signal of reception antenna.
In addition, have direction and adjust signal generation parts, the signal that is obtained by filtering operation is carried out signed magnitude arithmetic(al) to be handled, according to the resulting signal level of the result of this signed magnitude arithmetic(al), the direction that generates reception antenna is adjusted signal, and uses the direction adjustment signal of this generation to carry out the direction adjustment of reception antenna.
Also possesses the direction adjustment signal transformation that will generate for the parts of the voice signal that changes one of at least at interval corresponding to the continuation of the level of received signal, tonequality, volume, sound be transformed to the parts of the light signal that color, brightness, flicker change one of at least at interval and be transformed to arbitrary at least parts in the parts of demonstration numerical value, character, curve signal one of at least.
In addition, during averaging processing, filtering operation, carry out control, make the frequency of oscillation that receives local oscillator constant.
In addition, the interior arbitrary signal of control signal of the direction of signal that direction adjustment signal transformation roughly is directly proportional for the signal that roughly is directly proportional with the virtual value of received signal or with the performance number of received signal or the signal that roughly is directly proportional with the dB value (logarithm value) of received signal or the control The Cloud Terrace of adjusting the reception antenna direction.
The invention effect
If use the direction regulating method of reception antenna of the present invention, then adjust the starting stage in the direction of reception antenna, even if the CN of the ofdm signal that receives is than for about-7dB, promptly, for example the frequency domain width is the noise figure of 17MHz, primary amplifier when being 4dB, even if receiving electric field is-140dBm about, also can accurately detect the existence of ofdm signal, but the limit changes the direction of reception antenna, and the level of the ofdm signal that the limit search receives becomes maximum direction.
In addition, also can construct the system that the direction of using the incoming level signal calculate easily to carry out reception antenna is adjusted.
Description of drawings
Fig. 1 is the block diagram that expression reception antenna direction of the present invention is adjusted an embodiment.
Fig. 2 is the block diagram that expression reception electric field of the present invention is calculated an embodiment of portion 4.
Fig. 3 is the block diagram of existing antenna direction Adjustment System one example of expression.
Fig. 4 is the ideograph that expression OFDM symbol constitutes.
Fig. 5 is that expression receives the ideograph of signal that electric field is calculated each one of portion 4.
Fig. 6 is that expression receives the not ideograph of the phase place change of the complex multiplication output Zmul (m) fixedly time of Lo frequency.
Fig. 7 is that expression receives the level of electric field signal and the figure of C/N.
Embodiment
Below, describe embodiments of the invention in detail with reference to illustrated execution mode.
Fig. 1 is the figure of the expression first embodiment of the present invention.As mentioned above, the ofdm signal that arrives receiving system is received antenna 1 and receives, and by after receiving radio-frequency head 2 and carrying out frequency conversion, is transformed to baseband signal.Obtain receiving sampling serial Zin (m) (m is a sampling sequence number) behind this baseband signal input A/D translation circuit 3.Afterwards, through the path of the principal series that are made of FFT (adjustment Fourier transform) circuit 6 of the information code that is used for demodulate transmitted, demodulation section 7 etc., D outputs to external device (ED) with restituted signal.
In addition, receive the serial Zin of sampling (m) and be input to the Synchronous Processing portion 8 that makes clock timing or carrier frequency and transmission signal Synchronization, synchronizing signal SYNC is received signal regularly as control, dispensing is all to the OFDM acceptance division.
And, receive the serial Zin of sampling (m) when being connected with them, be connected to and calculate the reception electric field that receives electric field and calculate in the portion 4, will calculate reception electric field signal R that portion 4 obtains and be connected in direction and adjust on the signal generation 5, generate the direction adjustment signal C of reception antenna 1 by receiving electric field.
Below, the formation of calculating portion 4 as the reception electric field of the object of the invention is described in further detail.
Fig. 2 is that expression receives the pie graph that electric field is calculated portion 4.Be connected on the effective code delayer 41 from the reception of the A/D translation circuit 3 serial Zin (m) that samples, the reception that is postponed by effective code serial Zin (m-M) output of sampling is connected on the complex multiplier 42.On another input terminal of complex multiplier 42, connect from the reception of A/D translation circuit 3 serial Zin (m) signal of sampling.As described later, the output signal of complex multiplier 42 is connected on the integrator 43, via absolute value device 44, as receiving electric field signal R output.
Calculate in the portion 4 at this reception electric field, because enforcement has utilized the processing of the guide interval signal correlation of OFDM, so before explanation reception electric field is calculated the action of portion 4, the ofdm signal that comprises the guide interval signal is described with Fig. 4.
The OFDM mode is to come hundreds of-thousands of carrier waves (carrier) and the transmission manner of digital modulation with the constant frequency arranged spaced with Ts ' during the constant sign indicating number respectively.In the work that is modulated into ofdm signal, use the IFFT (contrary high speed Fourier transform) of M (for example M=1024) that count usually.1 sign indicating number of the transmission signals of sending from transmitter side is by making carbon copies the guide interval signal a ' formation that the Mg the Tg order during the guiding before the Ts during the effective code with the signal (A+a) of Ts during the effective code that ofdm signal was constituted of an IFFT modulated M point with the signal a of Tg during last Mg (for example Mg=128) point of 1 sign indicating number.In addition, b of next yard and b ' part too.
According to above knowledge, the processing of being calculated portion's 4 enforcements by the reception electric field of Fig. 4 is described with Fig. 5.By A/D translation circuit 3 sampling, be input to and receive electric field and calculate the reception of Fig. 5 (a) of portion 4 and sample serial Zin (m) shown in Fig. 5 (b), postponed the number of samples M (for example M=1024) of Ts during the effective code to be equivalent to by effective code delayer 41.This signal Zin (m-M) that has postponed Ts during the effective code with postpone before signal Zin (m), carry out complex algorithm by complex multiplier 42 at each sampled point, calculate
Zmul(m)＝Zin(m)×Zin(m-M)
* ...(1)
The waveform of this complex multiplication signal is shown among Fig. 5 (c), (d).
State diagram when Fig. 5 (c) is expression C/N infinity.Here, because be identical signal component under undistorted ideal conditions as the signal of a of guide interval signal and a ', b and b ' (dotted line among the figure), so have correlation during this guide interval, degree of correlation is than big during other.
In the starting stage of the direction adjustment of reception antenna 1, do not establish more receiving system Lo frequency (local oscillation frequency) synchronously, the complex vector located signal that is made of I component and the Q component of Fig. 5 (c) becomes the signal that rotates to any direction.If establish the synchronous of Lo frequency, then the phase place of complex vector located signal becomes 0 degree, only correlated components occurs at I component.
Here, the noise component(s) that during the guide interval that receives the serial Zin of sampling (m), contains in (a and a ', b and b ') for a long time because the no correlation of noise component(s), so the level of this correlated components diminishes.Therefore, if the correlation during the reduction guide interval means that then the noise component(s) that contains among the reception serial Zin of sampling (m) is many, it is low promptly to receive electric field level.On the contrary, big if degree of correlation becomes, mean that then the reception electric field level is big.
But for example the noisiness that contains under the such environment of C/N decline-5dB is also many, shown in Fig. 5 (d), be difficult to from waveform obtain judging during the guide interval with outside during the waveform correlation of degree of correlation difference.In addition, under this environment, because the also establishment synchronously of error detecting code sign indicating number regularly, so be difficult to judge that guide interval is regularly.
Therefore, in the present invention, I component, the Q component of the output signal Zmul (m) of complex multiplier 42 are implemented equalizations by integrator 43 respectively handle, suppress to upset component, extract effective correlated components.Promptly, if the noise quantitative change that contains is many, then shown in Fig. 5 (d), be difficult to output signal Zmul (m) by complex multiplier 42 self obtain judging during the guide interval with outside during the waveform correlation of degree of correlation difference, but carry out integration (equalization processing) by output signal Zmul (m) by 43 pairs of complex multipliers 42 of integrator, be not correlated with owing to have during beyond during the guide interval, so the integral result beyond during the guide interval converges to 0.
On the other hand, during guide interval in because have correlation, so, can obtain depending on the degree of correlation of C/N by implementing integral processing.
In addition, with regard to utilizing GPS etc., system during the receiving system side has absolute time and can hold guide interval,, the inhibition effect that upsets component is improved by with during being defined as guide interval between integration period.
In addition, with regard to the formation of integrator 43, can handle, be low pass filter (below be called LPF:Low Pass Filter) or realize by the LPF that iir filter constitutes by the rolling average that FIR filter etc. constitutes.With regard to the time constant of this LPF,, be desirably in hundreds of msec as following the trail of as early as possible in the time constant of the direction adjustment control of antenna.
In addition, when implementing integral processing, must keep constant with receiving the Lo frequency.As mentioned above, do not establishing under the synchronous situation, the phase place of the output signal Zmul of complex multiplier 42 (m) is uncertain.Here, change in time if receive the Lo frequency, then as shown in Figure 6, the phase place of Zmul (m) also can change.Sort signal is being carried out under the situation of integral processing, the useful correlated components of Zmul (m) also averages out, and can be converged 0.Therefore, must carry out keeping constant and the phase place of Zmul (m) being become constant control with receiving the Lo frequency.
Like this, the mean value input absolute value device 44 of the Zmul (m) that will be obtained by integrator 43 is calculated the absolute value of I component and Q component.As the calculation method of absolute value,, can calculate square reception electric field signal R that is directly proportional with received power by the quadratic sum of computing I component and Q component as the formula (2).
I
2+Q
2 ...(2)
In addition, as the formula (3), the square root of the quadratic sum by computing I component and Q component also can be calculated the reception electric field signal R that is directly proportional with received power.
(I
2+Q
2)
0.5 ...(3)
But, usually in receiving system, use following mode, promptly after carrying out the control of level that the level that will be changed big received signal by automatic gain control (AGC:Automatic Gain Control) circuit under condition of acceptance becomes substantial constant, implement various signal processing.Therefore, input receives electric field and calculates the power of the signal Zin (m) of portion 4 and also remain substantially constant.
Under the situation of carrying out this control, calculate the value that the reception electric field signal R of portion 4 is not and the reception electric field is directly proportional from receiving electric field.Especially as shown in Figure 7, if C/N uprises, even receive electric field level and become big, the level that then receives electric field signal R can be saturated under certain steady state value.But, be under the situation of zone of saturation at the level that receives electric field signal R, also establish synchronously, obtain the above reception electric field of specified level, finish so can be judged as the direction adjustment of antenna.
As mentioned above, will calculate the reception electric field signal R input direction adjustment signal generation 5 that portion 4 calculates, be transformed into the signal of the adjustment that is suitable for reception antenna 1, adjust signal C output as direction by receiving electric field.For example when implementing the adjustment of reception antenna 1, for the adjustment person who makes reception antenna is easy to adjust, incoming level is high more, then is high more sound for this direction adjustment signal C.Perhaps, output makes incoming level direction high more, the then narrow more at interval contour frequency sibilant rale generation of interrupted sound adjust signal.Perhaps, observe the change in voltage of adjusting signal C by the direction of generations such as oscilloscope on the limit, the limit is adjusted this level and is become maximum etc., limit and measure the incoming level limit and adjust under the situation of direction of reception antenna, will become the value transform of incoming level signal the value, for example dB that are easy to per-unit system and be worth equivalent resulting signal and adjust signal output as direction for adjusting.Perhaps, measure the incoming level limit on the instrument limit that use to show incoming level and adjust under the situation of direction of reception antenna, control is adjusted signal C corresponding to the signal of the instrument show value of the length of brightness, color or the display pole of incoming level etc. as direction export.Perhaps when the The Cloud Terrace of mobile receiver aerial slightly, by making with the following method, promptly when incoming level increases, further move to equidirectional, when reducing, move round about, on optimum orientation, control reception antenna thus, at this moment, will be the value transform of incoming level signal that the resulting signal of value that cradle head control become to be easy to per-unit system is adjusted signal C as direction and exported.
Like this, if use the receiving system of the OFDM mode of present embodiment, then the CN of the ofdm signal of Jie Shouing ratio become-below the 5dB, with before identical method, promptly use in the antenna direction regulating method of the mode that receives power-level detector or Fig. 3, even if even the starting stage that ofdm signal exists the direction of the reception antenna also can't detect to adjust, the existence of ofdm signal can not only be detected, and the power level and the variable quantity thereof of the ofdm signal that receives can also be recently measured with high SN.
Therefore, can construct following system, but the limit changes the direction of reception antenna, the ofdm signal level that the limit search receives becomes maximum direction, uses the direction of calculating to adjust signal and easily carries out the direction adjustment of reception antenna.
Claims (5)
1. the antenna direction regulating method of an OFDM receiving system is characterized in that:
In the receiving system of the transmitting device of the ofdm signal during transmission comprises guide interval, the above-mentioned ofdm signal that execution receives, with complex multiplication to the signal of the delay of length during this ofdm signal execution significant character, at least the signal during the guide interval of the resulting complex multiplication signal of the result of this complex multiplication is carried out equalization to be handled, handle handle the signal execution signed magnitude arithmetic(al) that obtains by above-mentioned equalization corresponding to receiving electric field level, according to the resulting signal level of the result of this signed magnitude arithmetic(al), generate the direction adjustment signal of reception antenna, and use the direction adjustment of this generation to carry out the direction adjustment of reception antenna with signal.
2. antenna direction regulating method according to claim 1 is characterized in that:
As above-mentioned signed magnitude arithmetic(al), calculate in following at least:, calculate square proportional reception electric field signal R1 with received power by the quadratic sum of computing I component and Q component; By square root sum square of computing I component and Q component, calculate and the proportional reception electric field signal of received power R2.
3. antenna direction regulating method according to claim 2 is characterized in that:
The direction adjustment of above-mentioned generation is made as arbitrary at least signal in following three kinds of signals with signal: corresponding to the level of the above-mentioned ofdm signal that has received and make the direction adjustment voice signal of at least one variation in the interrupted interval of tonequality, volume, sound; The direction adjustment light signal of at least one variation in color, brightness, the flicker at interval; The signal of at least one in demonstration numerical value, character, the curve.
4. OFDM receiving system is the receiving system that transmission comprises the transmitting device of the ofdm signal during the guide interval, it is characterized in that:
Possess: the complex multiplication operation parts, carry out the above-mentioned ofdm signal receive and this ofdm signal is carried out the complex multiplication of the signal of the delay of length during significant character; And the filtering operation parts, the signal during the guide interval at least of the resulting complex multiplication signal of the result of this complex multiplication is carried out the low-pass filtering computing; Have the direction adjustment and generate parts with signal, this direction adjustment generates parts with signal the signal that is obtained by above-mentioned filtering operation is carried out the signed magnitude arithmetic(al) processing, according to the resulting signal level of the result of this signed magnitude arithmetic(al), generate the direction adjustment signal of reception antenna.
5. receiving system according to claim 4 is characterized in that:
As described signed magnitude arithmetic(al), calculate in following at least:, calculate square proportional reception electric field signal R1 with received power by the quadratic sum of computing I component and Q component; By square root sum square of computing I component and Q component, calculate and the proportional reception electric field signal of received power R2.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP269995/2004 | 2004-09-16 | ||
| JP2004269995A JP4295183B2 (en) | 2004-09-16 | 2004-09-16 | Antenna direction adjusting method and OFDM receiving apparatus |
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| CN1750432A CN1750432A (en) | 2006-03-22 |
| CN1750432B true CN1750432B (en) | 2010-08-04 |
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| JP (1) | JP4295183B2 (en) |
| KR (1) | KR100738757B1 (en) |
| CN (1) | CN1750432B (en) |
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| JP5780647B2 (en) * | 2011-09-15 | 2015-09-16 | 株式会社日立国際電気 | Receiving apparatus and antenna direction adjusting method thereof |
| KR102173994B1 (en) * | 2014-03-18 | 2020-11-04 | 주식회사 만도 | Tuning method and control device of vehicle radar |
| CN112911223B (en) * | 2021-01-15 | 2022-11-22 | 四川一电航空技术有限公司 | Image processing method, device and equipment based on aircraft and storage medium |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1261228A (en) * | 1998-11-26 | 2000-07-26 | 松下电器产业株式会社 | Orthogonal frequency diversity receiver |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100487304B1 (en) * | 2001-08-17 | 2005-05-04 | 엘지전자 주식회사 | Digital TV receiver having embebdded internal antenna and antenna controlling apparatus |
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2004
- 2004-09-16 JP JP2004269995A patent/JP4295183B2/en not_active Expired - Fee Related
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2005
- 2005-09-14 CN CN2005100992949A patent/CN1750432B/en not_active Expired - Fee Related
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1261228A (en) * | 1998-11-26 | 2000-07-26 | 松下电器产业株式会社 | Orthogonal frequency diversity receiver |
Non-Patent Citations (3)
| Title |
|---|
| JP特开2001-144725A 2001.05.25 * |
| JP特开2003-115787A 2003.04.18 * |
| 同上. * |
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| JP4295183B2 (en) | 2009-07-15 |
| CN1750432A (en) | 2006-03-22 |
| JP2006086855A (en) | 2006-03-30 |
| KR20060051272A (en) | 2006-05-19 |
| KR100738757B1 (en) | 2007-07-12 |
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