CN101326683A - Self-installable switchable antenna - Google Patents

Abstract

A system, method, and apparatus for selecting a set of antennas, for use during operation of a radio system, from a plurality of antennas. The system, method and apparatus may include selecting one antenna that is part of an array of antennas. Then measuring characteristics of radio signals received at the antenna. The selection and measuring of characteristic is repeated for a desired number of antennas in the array. Then, the measurements are combined, and the combinations of antennas are ranked based upon the combined measurement. From the ranking combinations of antennas are selected for use during operation of a radio system.

Description

Can be from the switchable antenna of installing

Technical field

The present invention relates to be used for the multiaerial system of communication system, relate more specifically in being used for the multiaerial system of communication system, select antenna.

Background technology

The conventional wireless communication system has facilitated the two-way communication between a plurality of subscriber units and the wireless network infrastructure.Generally speaking, radio infrastructure is fixed, and subscriber unit can be that fix or mobile, and perhaps its combination is fixing and moves.The typical environment of wireless network operation comprises structure and the obstacle that much may block or reflect wireless signal between subscriber unit and infrastructure when wireless signal is propagated.For example, when signal was propagated, it may be by the wall in the wireless environment, people or the reflection of other barriers.Because signal is propagated and is reflected, so it may arrive receiver with the angle that is different from the directapath between reflector and the receiver.

Wireless environment also changes in time.For example, in WLAN, the barrier in the environment can move, and for example the people is walking about, and perhaps furniture or equipment are moved.In addition.If wireless receiver or reflector move, then moving of they also changed the position of barrier with respect to receiver or reflector.When wireless environment changed, signal also changed in selected path during by this environmental dissemination.The change of propagation path means, do not know signal with where to arriving at receiver from reflector.

Fig. 1 is the figure of the example of wireless network 100.As shown in Figure 1, this wireless network comprises reflector 102 and receiver 104.Also there is barrier 106 in the typical environment that wireless network 100 is moved.In outdoor environment, the example of barrier 106 comprises people, building, automobile, tree etc.In indoor environment, some examples of barrier 106 comprise wall, people, furniture, equipment, people etc.As mentioned above, environment also changes in time, and barrier 106, reflector 102 or receiver 104 move relative to each other.

As shown in Figure 1, when wireless signal transmitted between the antenna 120 of reflector 102 and receiver 104, it may be subjected to the blocking-up and the reflection of barrier 106 in the surrounding environment.Because directly sight line (LOS) path 110 is by one of them barrier 106 blocking-up, so the example of representing among Fig. 1 can be called non-sight line (NLOS) communication environments.Signal is reflected by barrier by this environmental dissemination and other situations in the various different paths of process also are like this.Among Fig. 1 illustration four examples 110,112,114 and 116 of these " multipath " signals.Shown in the example among Fig. 1, multipath signal can arrive at receiver 104 from different directions.

In order to solve the unknown direction problem of this received signal, many wireless devices have used omnidirectional (omni direction) antenna.Although omnidirectional antenna can receive the signal from any direction, because there is not antenna gain, so the signal that receives is not optimum.Directional antenna has the antenna gain that is better than omnidirectional antenna, but because it is directed, so it is only to receive the signal from specific direction.Yet, because wireless environment may change, so Fixed directional antennas possibly can't provide enough performances.

A kind of technology that is used for strengthening the performance of directional antenna is an antenna switching system.Typical antenna switching system comprises according to the in any direction a plurality of antennas or the antenna oscillator of the mode arrangement of received signal.Can utilize this antenna switching system to select the individual antenna oscillator, thereby select the antenna of the direction of use " sensing " received signal.

Therefore, the method and apparatus that need be optimized to the sky line options in the multiaerial system.

Summary of the invention

These system and methods have several characteristic, and any single feature all can not obtain its expectation attribute.Under situation about not limiting as the expressed scope of following claim, below concise and to the point its more prominent features of discussing.After considering that this discusses, especially reading title for after the part of " embodiment ", the feature that one will understand that these system and methods is how several advantages of being better than traditional formation technology are provided.

According to the present invention, wish under the situation that adopts two or more reception antennas, the antenna system diversity in non-sight line (NLOS) or obstacle sight line (OLOS) communication environments to be optimized.In other words, wish that the space diversity that employing is operated in the system of the one or more antenna feeds under the serious multipath fading environments is optimized.Also wish when increasing system gain, to provide the feature of the omnidirectional antenna area of coverage (coverage) under NLOS or the OLOS environment.In client device (CPE) or subscriber station (SS), particularly can't carry out by optical instrument under the NLOS environment of direct antenna alignment, this system can be from installing.This system also be suitable for supporting at the time become the antenna alignment of NLOS or OLOS communication environments.

On the one hand, a kind of method of combination of antennas of selecting from a plurality of antennas comprises the antenna of selection as the part of aerial array.Measure the feature of the wireless signal that receives at this antenna place then.Hope number of antennas repeat the selection and the measurement of feature mid-term to array, (ranking) then makes up measured value and sorts.Sort according to this and to be chosen in employed combination of antennas of wireless system working stage or combination of sets.

Wireless signal can be OFDM (OFDM) signal.In addition, the feature of measuring wireless signal for example comprises, synchronizing signal in the measuring-signal (amble) (preamble, middle synchronizing signal or postamble) for the degree of correlation of known synchronization signal, combination from the signal that two or more antennas receive, measure then in the composite signal synchronizing signal for the degree of correlation, measure error vector measurement value, the signal to noise ratio of known synchronization signal, carry letter than or the signal fadeout measured value.

On the other hand, a kind of antenna system comprises a plurality of antennas.This system also comprises and links to each other with these a plurality of antennas and be suitable for selected antenna is couple to the switching matrix that switches output (switch output).Radio module links to each other with this switching output and is suitable for received RF signal.The measurement module that existence links to each other with radio module, this measurement module are suitable for measuring the feature of the radiofrequency signal that radio module receives.The switching output of this switching matrix is coupled with control module, and this control module is suitable for receiving the feature that records, and these a plurality of antennas which control selects.

This control module can be one at a time or is side by side selected antenna, and according to the combination of the measured value of each antenna these antenna is sorted.This control module sorts according to this and is chosen in combination of antennas or the antenna sets intersection that working stage uses then.This antenna system can also comprise that second switches output, and second radio module that links to each other with this second switching output.In this constituted, control module selected to be couple to communicatedly antenna of first radio module or the antenna collection that signal is combined, and will be couple to second antenna of second radio module or the antenna collection that signal is combined communicatedly.Can use the switching output and the radio module (radio) of any desired quantity.

The description of various aspects of the present invention should be easy to expect other features and advantages of the present invention according to following the explanation by by way of example.

Description of drawings

Fig. 1 is the figure of example wireless network.

Fig. 2 is the figure of the example multi-antenna module that can use at the receiver place.

Fig. 3 is the figure that the wireless network of viewpoint of the present invention has been described.

Fig. 4 is the figure of the another kind of example multi-antenna module that can use at the receiver place.

Fig. 5 is the functional block diagram of the execution mode of antenna system.

Fig. 6 is the flow chart that the sky line options in the multi-antenna array has been described.

Fig. 7 is the picture group that relative " performance " of each antenna is described by graphics mode.

Fig. 8 is the picture group that relative " performance " of various combination of antennas is described by graphics mode.

Embodiment

After having read specification, those skilled in the art are easy to expect how to implement the present invention by various alternative embodiment and alternative application.Yet,, be to be understood that what these execution modes just provided by by way of example rather than ways to restrain though will describe numerous embodiments of the present invention here.Equally, the scope or the range that detailed description of various execution modes should be construed as limiting the invention.

Hope is optimized the antenna system diversity under non-sight line (NLOS) or obstacle sight line (OLOS) communication environments under the situation that adopts two or more reception antennas.In other words, wish that the space diversity that employing is operated in the system of one or more antenna feed under the serious multipath fading environments is optimized.Also wish when increasing system gain, to provide the feature of multidirectional antenna coverage under NLOS or the OLOS environment.In client device (CPE) or subscriber station (SS), particularly can't carry out by optical instrument under the NLOS environment of direct antenna alignment, this system should be from installing.Also need at the time become the suitable antenna alignment of NLOS or OLOS communication environments.

Fig. 2 is the figure of the example multi-antenna module 200 that can use at the receiver place.Four directional antennas 202,204,206 and 208 are arranged in the example antenna module 200 shown in Figure 2, and each all is configured to receive in the sector of about 90 degree or transmit.Be chosen in wireless system working stage (for example signal receives or emission during) and activate in the antenna 202,204,206 and 208 which, can improve the performance of wireless system.

Fig. 3 is the figure of the wireless network of explanation viewpoint of the present invention.Fig. 3 and Fig. 1 are similar, have just replaced the antenna 120 at receiver 104 places with the Anneta module 200 of Fig. 2.In the example of Fig. 3, the multipath signal 112,114,116 and 118 that arrives at Anneta module 200 arrives at the different antennae 202,204,206 and 208 of Anneta module 200.Because multipath signal 112,114,116 is different with 118 common " quality ", thus the preferred selection version of receiving multipath signals, and abandon other versions.For example, multipath signal 112 had only reflected once before being received by antenna 202, and multipath signal 116 had reflected five times before being received by antenna 206. Multipath signal 114 and 118 had reflected twice before being received by antenna 204 and 208 respectively equally.

Because multipath signal 112,114,116 has all passed through different paths with 118, so they can experience the deterioration or the distortion of different amounts usually.For example, because 112 of multipath signals have reflected once, so it may experience minimum deterioration.Although multipath signal 114 and 118 has all reflected twice, because comparing with multipath signal 118, multipath signal 114 passed through short overall path length, so multipath signal 114 may experience less deterioration.And, because multipath signal 116 has reflected five times, so it may experience maximum deterioration.Because these multipath signals arrive at antenna after the deterioration that has experienced different amounts, so " quality " of signal is different.Therefore can preferably only activate the antenna selected and (deactivate) other antennas of stopping using.

Fig. 4 is the figure of the another kind of example multi-antenna module 400 that can use at the receiver place.In this example antenna module 400, antenna system comprises eight directional antennas 402,404,406,408,410,412,414 and 416, and each all is configured to from the sector received signal of about 45 degree.Select to activate the performance which antenna can improve receiver.Therefore each antenna in the Anneta module 400 has all covered little sector, makes antenna gain increase to antenna gain above the antenna in the Anneta module 200 of Fig. 2.Though Fig. 2 and 4 illustrations four antennas and eight antennas, may use the antenna of any desired number.

Also provide space diversity as illustrative multi-antenna module in Fig. 2 and 4.Utilize space diversity, the input signal from two or more spatial diversity antennas is carried out mathematical combination, produce quality and be better than from any the signal in these two independent signals of antenna.Optional selecting antennas array can be used for space diversity is optimized, and has realized also that simultaneously the user can fix up an aerial wire.Choice criteria can based on the optimum of the reception antenna of the maximizing performance of selecting to make assembled scheme to or collection.

Fig. 5 is the functional block diagram of the execution mode of antenna system 500.Antenna system 500 can be supported MIMO (multiple-input, multiple-output) technology.Antenna system 500 comprises a plurality of configurable antennas 502～508.Though described four configurable antennas, also can use more or less this oscillator.Antenna switch matrix 510 can be couple to radio module 512 communicatedly with selected antenna 502～508.

Radio module 512 carries out demodulation from selected antenna 502～508 received RFs (RF) signal to the signal that receives, and sends a baseband signal to data interface module 514.Radio module 512 also from data interface module 514 receiving baseband signals, carries out demodulation to base band data, and sends the RF signal to selected antenna 502～508.Radio module 512 also can be couple to measurement module 516 communicatedly.As described further below, measurement module 516 is estimated the feature of radio module from the signal of selected antenna reception.For example, measurement module 614 can be determined the power level of received signal, perhaps the degree of correlation, perhaps other features.

In one embodiment, during the selection action of antenna system, be sent to radio module 512 from the signal of expecting antenna 502～508.The output of radio module links to each other with measurement module 516.For example, can be sent to radio module 512 one at a time from the signal of each available antenna 502～508, these signals are sent to measurement module 516 there.Measurement module 516 is analyzed to the received signal, to determine " quality " of signal.Give an example, each aerial signal is sent to radio module 512 reaches is enough to catch at least one synchronizing signal (preamble, postamble, middle synchronizing signal) from the signal that is received from each antenna period.This signal of measurement module 516 subsequent analysis is determined its quality by measuring (a plurality of) synchronizing signal that is received with the degree of correlation of (a plurality of) known reference synchronizing signal.The standard of the synchronizing signal degree of correlation as the received signal that is assigned to same reflector or base station can be come the quality of antenna feed is sorted.Base Station Identification (BSID) can be used to judge between two received signals with identical synchronizing signal degree of correlation (amble correlation) that sent by different base station or peer users station (SS).

The signal quality of each selected antenna that measurement module 516 will be determined sends to control module 518.Control module 518 links to each other with antenna switch matrix 510, is used for optionally will expecting that antenna is couple to radio module 512.As described further below, control module 518 is estimated the signal quality that receives from measurement module 516 at each selected antenna 502～508.After the antenna 502～508 of having estimated desired amt, control module 518 can be chosen in the antenna that working stage is couple to radio module 512 and 520.Should be noted that control module 512 also controls antenna switch matrix, optionally antenna 502～508 is coupled to radio module 512 in the choice phase.

Control module 518 is estimated the various combinations of aerial signal, to determine the preferred antenna combination.As described further below, control module 518 utilizes various analytical technologies to estimate which kind of combination of aerial signal provides preferred feature, for example, and " the most smooth " response.In one embodiment, by " measured value " of definite performance that makes up with respect to other combinations, the various combinations of arranging aerial signal.Following table 1 is to want the illustrated examples that may sort of five aerial arrays of the optimum combination of definite two antennas in the array of five antennas.In table 1, more represented the performance that strengthens with more comparing near the value of " 0 " near the value of " 1 ".

	Antenna 1	Antenna 2	Antenna 3	Antenna 4	Antenna 5
						Antenna 1		0.8	0.9	0.3	0.1
Antenna 2	0.8		0.3	0.3	0.2
						Antenna 3	0.9	0.3		0.2	0.4
Antenna 4	0.3	0.3	0.2		0.6
						Antenna 5	0.1	0.2	0.4	0.6

Table 1

Table 1 is just illustrative, and the value representation of listing in the table is better than other combination of antennas from the combination of the signal of antenna 1 and 3 in this example.Example shown in the table 1 has only been estimated the combination of two antennas.In other examples, can make up the hope antenna of any amount, and estimate these combinations at performance.

Return Fig. 5, can then sampling be made up to estimate the performance of this combination one at a time to sampling from the signal of each expectation antenna 502～508.In another embodiment, can sample to sampling simultaneously, then sampling be made up to estimate the performance of this combination from a plurality of antennas.For example,, then except that first radio module 512, also use second radio module 520, can sample to two antennas simultaneously if the combination of two antennas is estimated.For example first antenna, 502 signals first radio module 512 can be sent to, and second antenna, 506 signals second radio module 520 can be sent to simultaneously.Wireless signal from two radio modules 512 and 520 can be sent to measurement module 516, determine two quality of signals there and send it to control module 518.Though the example shown in Fig. 5 has only two radio modules, can use the radio module of any desired number to obtain the sampling of desired number simultaneously.

Can come optionally constructing antennas system 500 in response to control signal, constitute thereby create the different antennae that can comprise the different antennae pattern.By selecting one or more antenna 502～508, antenna system can instruct or control the gain of entire antenna system 500.

System may need a reception antenna feed, select in the space diversity formation as going into singly (MISO) or space time coding (STC) 2x1 more, perhaps need two or more to receive feed, receive in the formation as multiple-input, multiple-output (MIMO) or STC 2x2.At working stage, depend on that system needs single antenna feed or many antenna feed, can enable the highest definite in the choice phase ordering antenna feed, and other antennas in forbidden energy (disable) array.If system is a multiaerial system, then can form the input signal of receiver to a plurality of signal application combination techniques.

For example, under the NLOS environment, owing to repeatedly reflecting and/or reflecting, the direction of optimum performance radio frequency (RF) energy is unknown.As shown in Figure 3, " the best " performance RF signal may arrive at receiver from uncertain direction.Therefore wishing to reach 360 degree antennas covers.Yet, the low antenna gain that consideration is associated with omnidirectional antenna, using this class antenna may not be optimum solution.Therefore, utilize the space combining scheme, can use sectorization to cover and help the optimization system gain.Return Fig. 3, antenna system 200 comprises four antennas 202～208, and each all has 90 degree horizontal coverage pattern.For example, can be arranged as antenna 202 respect to one another and 206 or these antenna any other the combination on receive the received signal that the optimal spatial composite behaviour is provided.

If adopt more complicated antenna system, then can further increase system gain.For example, use eight antenna systems 400 as shown in Figure 4 can provide the gain of increase.For example, can on the antenna 404 and 414 that has 45 degree horizontal coverage pattern respectively, receive the optimum RF signal, and corresponding gain increases.Though Fig. 2 and the example shown in 4 are represented each antenna in the array aerial array of identical replace mode is arranged all, other formations also are possible.For example, antenna system can comprise the antenna with different replace modes, and for example some oscillator has the replace mode of 90 degree, and other antennas have the replace mode of 45 degree, perhaps wish any other combination of replace mode.

In addition, can periodically use choice phase or processing to solve the change of communication environments and the coherent signal deterioration that upper layer application (data link layer) monitors.For example, the environment that rate of change is high may need a kind of with under fixed environment, compare higher antenna and reselect rate.

Use described day line options technology, can improve the operation of RF system under serious NLOS multi-path environment significantly.For example, if multiaerial system is the array of 90 degree fan antennas, then based on the H polarity gain difference of the same vertical beam angle of co-ordinated radiation pattern, gain is usually than the high 10～12dB of single omnidirectional antenna.Should be noted that the insertion loss that the antenna that is used for selecting antenna switches may reduce the correlated noise coefficient of receiver, thereby reduced system gain.The system gain of expectation rises to:

Δ SysGain=G _{H_90deg}-G _{H_OMNI}-L _SFormula 1

Wherein:

Δ SysGain: be under the identical situation of the vertical angle of co-ordinated radiation pattern, the system gain between moving based on the SS that select 90 degree fan antennas with omnidirectional antenna is poor.

G _{H_90deg}: be based on the horizontal antenna gain of 90 degree fan antennas of same vertical radiation pattern angle, represent with dBi.

G _{H_OMNI}: be based on the horizontal antenna gain of the omnidirectional antenna of same vertical radiation pattern angle, represent with dBi.

L _S: the group who is the operating frequency of antenna switching inserts loss, represents with dB.

Utilize formula 1, therein G _{H_90deg}=14dBi, G _{H_OMNI}=4dBi and L _SIn the example of＜=2dB, the raising of the Δ system gain of expectation is:

ΔSysGain＞＝8dB

Can use various other technologies to determine to select which antenna or antenna collection.For example, a kind of technology is the signal of individual inspiration from each antenna.Can synchronizing signal and known synchronization signal be compared by relevant treatment.Use the correlation measure of each antenna to come the performance of each antenna of comparison and select selective one, two or more " the bests " candidate then.If M available antenna arranged in the system, then there be M associative operation.

In one embodiment, input signal is carried out cross-correlation at known array.Cross-correlation operation has obtained and the corresponding peak of the quality of input sync signal.In the example that uses two signals, use two the highest peaks.Another character of correlation technique is that multipath reflection causes secondary, three correlations peaks, also has other relevant peaks sometimes., just represent very strong multipath and can be used to get rid of given oscillator to tangible peak in expectation relevant peaks external detection.In an example, can measure time amplitude at big peak then and write down difference by measuring the normalization amplitude of main relevant peaks, select.Followingly carry out the relevant of simple oscialltor:

$y\left(m\right)=\underset{n=0}{\overset{N-m-1}{\mathrm{\Σ}}}{x}_{n+m}{y}_n^{*}$ Formula 2

Wherein N is the length of correlated series.

Detection peak uses normalized to guarantee that comparison between the oscillator is under same scale.This has just obtained the single numerical value of expression based on relevant oscillator signal quality.Use for single output, select the oscillator of high numerical value.

The another kind of technology that can be used to determine to select which antenna or antenna collection is before carrying out measurement of correlation, and combination is from the received signal of two or more oscillators.Be used to determine selective " the best " candidate combinations subsequently from being correlated with of various combination.In this case, if M available antenna arranged in the system and have N output stream, then need _MC _NIndividual associative operation.For example,, and wish to select a two antenna set, then have 28 associative operations if there are eight aerial arrays.

The another kind of technology that is used for definite which antenna of selection or antenna collection can simply be determined " the best " combination of antennas of array based on time-domain signal.For example, estimate the incompatible definite combined feature of various antenna sets, for example, the mean receiving power of input signal, signal to noise ratio (snr) etc.

In addition, utilize the character of OFDM (OFDM) signal, can in frequency domain, carry out antenna ratio.For example, can utilize discrete Fourier transform (DFT) or some other equivalent process, will be converted to frequency domain from the synchronous signal sequence of each antenna.For example, can utilize error vector magnitude measured value, signal to noise ratio (snr) then, carry letter than (CIR), signal fadeout measured value, or some other tolerance or tolerance combination, determine quality of signals.Can select two or more " the bests " candidate based on the signal quality of determining then.Utilize this technology,, then have M frequency domain measurement operation if there be M available antenna in the array.

About above frequency-region signal performance measurement, can utilize discrete Fourier transform (DFT) or some other equivalent process, synchronous signal sequence is converted to frequency domain.If have M input array antenna and need N output stream, then before measuring frequency-region signal, be combined into N combination of M inlet flow.For example, can utilize error vector magnitude measured value, signal to noise ratio (snr) subsequently, carry letter than (CIR), signal fadeout measured value, or some other tolerance and tolerance combination, the quality of coming measuring-signal.Can select two or more " the bests " candidate based on these results.If have M available antenna in the array and need N output stream, then need _MC _NIndividual frequency domain measurement operation.

For example, if the signal that in two time frames, sends as shown in table 2:

	Tx antenna 0	Tx antenna 1
			Time t	s 0	s 1
Time t+T	-s 1 *	s 0 *

Table 2

Then the symbol of the received signal at two reception antenna places is listed in table 3:

	Rx antenna 0	Rx antenna 1
			Time t	r 0	r 2
Time t+T	r 1	r 3

Table 3

In the dual antenna receiver system, will be worth r _0...3Make up and recover the original s that sent ₀, s ₁Value.The combination of antennas that the present invention can be used to select to have Optimal Signals is used for the space-time receiver.For this reason, will be from the synchronizing signal r of an oscillator ₀, r ₁With r from second oscillator ₂, r ₃Make up, with the s that obtains estimating ₀, s ₁Signal.This combined treatment is abideed by S.Alamouti at IEEE Journalon Select Areas in Communications, in October, 1998, pp.1451-1458, the technology of describing in " A SimpleTransmit Diversity Technique for Wireless Communications " is incorporated it into here by reference.

Adopt the error vector magnitude measured value to come to create numerical value for the quality of selected oscillator combination.May array combination repeat this processing to other, and select highest quality combination (lowest total error vector magnitude).

In order to improve the consistency of mixing array aerial signal, for example can utilize relevant result of the time domain of each signal or the phase-detection/correcting circuit in the frequency domain, calculate relative feed delay.Timing or the phase place that can use delay circuit before the DFT or the phase rotation circuit after the DFT before signal is made up, to arrange them.For example, if antenna system comprises four aerial arrays, similar with illustrative array in above Fig. 2 and 5, then can select one or more antennas of signal " by force " to come to be the receiver feed, because comparing with omnidirectional antenna, directional antenna has more gain, so system gain increases.

In an example, utilize synchronizing signal in frequency domain, to carry out channel estimating.Measurement is carried out timing/phase place adjustment to input signal based on phase error.With signal transformation is frequency domain, to the portions of bandwidth of each antenna record decline.Select and make up (in frequency domain) antenna oscillator based on the ability that antenna oscillator replenishes each other.Fade measurement process comprises the amplitude of measuring the signal in each frequency (frequency bin) and the vector of storing the value that comprises each oscillator.Subsequently, by two candidates' vector is sued for peace, and to obtain with the vector calculation variance, come the comparison combination of antennas.Under the situation of 4x4 array, select the combination of two minimum oscillators of variance.This has obtained two streams of two combined elements.

For four layered transducer elements (representing in four oscillators each), carry out following comparison with A...D:

Min (var (A+B), var (A+C), var (A+D), var (B+C), var (B+D), var (C+D)) formula 3

Wherein " min " is minimum value function, and " var " is that variance is calculated:

${\mathrm{\σ}}^2=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{(x_i-\stackrel{\‾}{x})}^2$ Formula 4

In another example, can select any amount in the array (comprising all antennas) to wish antenna, their phase place or timings are separately adjusted, be used for being fed to the signal of receiver with establishment.For example, utilize the example of above four aerial arrays, if signal is by the emission of first antenna in the array and receives that then it has first phase shift in the path that depends in part on this signal arrival antenna at least.If second antenna of array receives the signal that is sent, and this signal chosen with this signal and arrived the different path of first antenna, and then the signal that receives at second antenna has second phase shift that is different from first phase shift usually.If omnidirectional antenna is used in this embodiment, the different phase shifts of the multipath signal that then receives will cause decline.Use antenna system described herein, the phase place of the signal that receives at the different antennae place or adjustment regularly can obtain better quality and reduce or eliminate the signal that will be fed to receiver of decline.

In one embodiment, can use timing/phasing.In an example, composite signal arranged reduce the decline that causes by phase mismatch.Can calculate thick correction of timing according to the position of relevant peaks in the time domain; Can in frequency domain, carry out phase-detection/correction.These two kinds of calculating can be carried out on synchronizing signal.

Return the example of Fig. 5, this antenna system comprises four antennas 502～508 and two radio modules 512 and 520.Can use the antenna and the radio module of varying number in other embodiments.In addition, data-interface 514 can receive base band data and be converted into the packet that will send to another system's (not shown).Equally, data-interface 514 can receive packet and be converted into the base band data that will send to radio module 512 and 520 from another system.In addition, data-interface 514 can also be configured to or transmit base band data, intermediate frequency (IF) signal or RF signal from another system.

In other embodiments, can provide other forms of signal to the receiver in another system.For example, if wish to provide " former " RF signal, then aerial signal 550 and 552 can be sent to other system from antenna switch matrix 510 from sky alignment receiver.This example has illustrated the example that has transmitted two former RF signals to another system.In other examples, can provide the former RF signal of any desired number to another system.In addition, if wish to provide base band data, then can provide baseband signal 560 and 562 to this another system from sky another system of alignment of selecting.In the example of Fig. 5, provide baseband signal to another system from two radio modules 510 and 520, in having other examples of additional radio modules, can provide additional baseband signals to another system.In another example,, can provide " former " frequency- region signal 570 and 572 to another system aerial signal being transformed from the time domain to frequency domain (for example in radio module 510 and 520) afterwards.By similar fashion, can also be from the former RF signal of the transmitter receipt another system, baseband signal or former frequency-region signal, and be used for from selected antenna 502～508 radiation signals.

In an example, at working stage, first antenna can be communicated by letter with first radio module 510, and second antenna can be communicated by letter with second radio module 520.Aerial signal can be by radio module 510 and 520 demodulation, and base band data can be sent to data-interface 514 (in two aerial signals of this combination), from data-interface 514 output composite signals.The composite signal of data-interface 514 outputs can be base band data, intermediate frequency (IF) signal or RF signal.

Antenna system with the antenna system 500 among Fig. 5 for example replaces conventional antenna, can improve the performance of existing system.For example, if existing system uses omnidirectional antenna, then can compare the improved multiaerial system of performance with omnidirectional antenna and replace omnidirectional antenna with selecting to provide.With reference to Fig. 5, the interface between antenna system 500 and the existing system can be at the difference of signal flow.For example, can be between antenna system 500 and the existing system at data-interface 514 and transmit data.In addition, can also radio module 512 and 520 and existing system between transmit base band data.Equally, can between antenna switch matrix 510 and existing system, transmit the RF signal.

Fig. 6 has been the illustration flow chart of the sky line options in the multi-antenna array.Flow process starts from frame 600.Flow process proceeds to frame 602 subsequently, determines whether that wishing to walk around automatic selection handles.Handle if wish to walk around automatic selection, then flow process proceeds to frame 604, manually selects antenna.Flow process proceeds to frame 606 and stops.

Return frame 602, if wish to select automatically antenna, then flow process proceeds to frame 608, selects first antenna.Flow process proceeds to frame 610 subsequently, determines the feature of the signal that received by selected antenna.Flow process proceeds to frame 614, determines whether to have estimated all expectation antennas.If all expectation antennas are not sorted, then flow process proceeds to frame 616, selects another antenna, and flow process proceeds to frame 610.Return frame 614, if sorted all expectation antennas, then flow process proceeds to frame 618, the feature of various combination of antennas is made up, and these combinations are estimated and sorted.Flow process proceeds to frame 620 subsequently, in response to ordering, selects the preferred compositions of antenna oscillator for working stage.Flow process proceeds to frame 606 subsequently and stops.

Following illustration explanation use another example of the advantage of frequency domain combination.Table 4 illustration the example collection of value of the bin magnitudes that samples from four antenna A～D of expression.

Bin magnitudes

A	50	55	48	60	72	60	50	40	30	20	25	27
													B	30	20	25	27	28	29	35	35	40	51	52	60
C	60	70	66	65	48	47	46	50	30	20	25	27
													D	30	20	25	27	28	29	35	35	40	51	52	35

Table 4

Table 5 shows the value that the performance of various combination of antennas is measured in explanation.In this embodiment, the value of combination is to determine by the bin magnitudes summation of the combination of two antennas is asked average to amplitude then.For example, the combination of antenna A and B is (50+30)/2=40 in first frequency.Also can adopt the other technologies of combination bin magnitudes.

A+B	40	37.5	36.5	43.5	50	44.5	42.5	37.5	35	35.5	38.5	43.5
													A+C	55	62.5	57	62.5	60	53.5	48	45	30	20	25	27
A+D	40	37.5	36.5	43.5	50	44.5	42.5	37.5	35	35.5	38.5	31
													B+C	45	45	45.5	46	38	38	40.5	42.5	35	35.5	38.5	43.5
B+D	30	20	25	27	28	29	35	35	40	51	52	47.5
													C+D	45	45	45.5	46	38	38	40.5	42.5	35	35.5	38.5	31

Table 5

For example, thus can use various statistical techniques to estimate to make up the ordering of determining various combinations.Following table 6 illustrations the example case study of illustrative combination in the table 5.

	Var	Min	Max	Avg
					A+B	36.6	35	58.5	46.2
A+C	134	20	62.5	46.2
					A+D	96.3	31	71	46.2
B+C	74.4	35	72	46.2
					B+D	134	20	62.5	46.2
C+D	72.3	31	62.5	46.2

Table 6

Fig. 7 is a picture group of representing relative " performance " of each antenna of listing in the table 5 with graphics mode.As shown in Figure 7, drawn the bin magnitudes of antenna A702, antenna B704, antenna C706 and antenna D708.

Fig. 8 is a picture group of representing relative " performance " of various combination of antennas with graphics mode.As shown in Figure 8, there is the combination 810 of combination 808, antenna B and D of combination 806, antenna B and C of combination 804, antenna A and D of combination 802, antenna A and the C of antenna A and B, and the figure of the combination 812 of antenna C and D.Figure by controlling chart 8 combination 802 of antenna A and B as can be seen is the most smooth responses on all frequencies.In addition, the combination 802 of antenna A and B is all more smooth than antenna A 702 independent among Fig. 7 or B 704.This example has illustrated in the mode of figure how combination of antennas can have the individual antenna that makes up with formation and compare more excellent performance characteristic.

Multiple declaration enforcement of the present invention has been described.Yet those skilled in the art can see, other enforcements also can be arranged and fall within the scope of the invention.For example, though above declarative description determine that by control module which antenna in the aerial array is used for the specific example of radio communication, these aspects can be undertaken and fallen in herein the scope by the other types controller.

Therefore, the present invention is not limited only to above-mentioned those enforcements.Those skilled in the art expect can often being implemented as electronic hardware, software, firmware or aforementioned combination in conjunction with the various illustrative modules of above-mentioned figure description and method step and the enforcement of disclosure here easily.For this interchangeability of hardware and software clearly is described, more than generally be functional various illustrative modules and the method step described with regard to them.With so functional hardware that is embodied as still is that software depends on application-specific and the design constraint that applies on whole system.Those skilled in the art can implement described functional to each application-specific by variation pattern, but such enforcement decision should be interpreted as causing breaking away from the scope of the invention.In addition, the function combinations in module or the step is for convenience of description.Without departing from the invention, specific function can be moved to another from a module or step.

And, various illustrative modules of describing in conjunction with the enforcement that discloses here and method step can be by general processor, digital signal processor (" DSP "), application-specific integrated circuit (ASIC) (" ASIC "), field programmable gate array (" FPGA ") or other programmable logic devices, discrete gate or transistor logic, the discrete hardware components that is designed to carry out function described herein, or its any combination realizes or carries out.General processor can be a microprocessor, but alternatively, processor can be any processor, controller, microcontroller or state machine.Also processor can be embodied as the combination of calculation element, for example, the combination of DSP and microprocessor, a plurality of microprocessor, combine one or more microprocessors of DSP core or any other such configuration.

In addition, the method for describing in conjunction with the enforcement that discloses here or the step of algorithm can directly pass through hardware, by the software module of processor execution, or the combination of the two is implemented.Software module can reside in RAM memory, flash memory, ROM memory, eprom memory, eeprom memory, register, hard disk, removable dish, CD-ROM or any other form storage medium of (comprising network storage medium).Exemplary storage medium can be connected to processor, thereby processor can write storage medium from read information and with information.Alternatively, storage medium can with the processor one.Processor and storage medium also can reside in the ASIC.

It is in order to make any those skilled in the art can both carry out or use the present invention that the above description of disclosed enforcement is provided.Those skilled in the art expect the various modifications to these enforcements easily, and under the situation that does not break away from the spirit and scope of the present invention, general rule described herein can be applied to other enforcements.Therefore, be to be understood that the description and the figure expression example enforcement of the present invention that present here, therefore represent the extensively theme of imagination of the present invention.Therefore the present invention's execution mode of being not intended to be limited to represent here, but give the widest range consistent with appended claim.

The title that the application requires on December 12nd, 2005 to submit to is the U.S. Provisional Patent Application 60/749401 of " Design ofa System andMethod for Switchable Antenna Selection Based on an OptimizedConfiguration "; And the title with submitting on February 17th, 2006 that on January 27th, 2006 submitted to all be the U.S. Provisional Patent Application 60/763196 of " Design of a Self-InstallableSystem and Method for Switchable Antenna Selection Based on a QualityRanking of OFDM and OFDMA Signals " and the priority of U.S. Provisional Patent Application 60/774428, here by reference with their full content introducing.

Claims (43)

1, a kind of antenna system, this antenna system comprises:

A plurality of antennas;

Switching matrix, it links to each other with these a plurality of antennas, and is suitable for selected antenna is couple to a plurality of switching outputs;

Radio module, it links to each other with the first switching output, and is suitable for received RF signal;

Measurement module, it links to each other with this radio module, and is suitable for measuring the feature of the radiofrequency signal that this radio module receives; And

Control module, it is suitable for switching output and controlling selecting in these a plurality of antennas which to be couple to first, wherein in the choice phase, this control module will be couple to first with will expecting antenna selectivity and switches output and receive the feature that records of the radiofrequency signal that received by selected antenna, this control module continues to select and receive measured value from these a plurality of antennas of desired amt, this control module makes up the measured value from combination of antennas then, and determines the expectation combination of antennas used in working stage.

2, antenna system according to claim 1, wherein this control module is selected antenna one at a time in the choice phase, and comes these antenna is sorted based on the feature that records.

3, antenna system according to claim 1, wherein said combination of antennas comprises the measured value from least two antennas.

4, antenna system according to claim 1, this antenna system also comprises:

Second switches output; With

Second radio module, it links to each other with the second switching output, wherein this control module selects to be couple to communicatedly an antenna of this radio module, with second antenna that will be couple to second radio module communicatedly, wherein the characteristics of radio signals that second radio module is received sends to this measurement module.

5, antenna system according to claim 4 is wherein carried out the measurement of radio signal that this radio module and second radio module are received simultaneously.

6, a kind of method of from a plurality of antennas, selecting the antenna collection, this method may further comprise the steps:

Select an antenna in the aerial array;

The characteristics of radio signals that measurement receives at this antenna place;

Expectation number of antennas in this array is repeated to select and measure;

The measurement set of expectation antenna is combined into a plurality of measurement in a closed series values;

Based on these measurement in a closed series values combination of antennas is sorted; And

The expectation combination of antennas that selection will be used at the duration of work of radio system.

7, method according to claim 6, wherein signal receiver is an orthogonal frequency-division multiplex singal.

8, method according to claim 6, the step of wherein measuring characteristics of radio signals comprise the synchronizing signal measured in this signal degree of correlation to known synchronization signal.

9, method according to claim 6, the step of wherein measuring characteristics of radio signals comprises that the signal to receiving from two or more antennas makes up, and measures synchronizing signal in the composite signal then to the degree of correlation of known synchronization signal.

10, method according to claim 6, the step of wherein measuring characteristics of radio signals comprises the error vector measurement.

11, method according to claim 6, the step of wherein measuring characteristics of radio signals comprises the measurement signal to noise ratio.

12, method according to claim 6, the step of wherein measuring characteristics of radio signals comprise measuring carries the letter ratio.

13, method according to claim 6, the step of wherein measuring characteristics of radio signals comprises the signal fadeout measurement.

14, method according to claim 6, this method is further comprising the steps of:

Determine the phase place of the signal that receives from the antenna of desired amt; And

Adjust the phase place of the signal of selected antenna collection.

15, method according to claim 6, this method is further comprising the steps of:

Determine the timing of the signal that receives from the antenna of desired amt; And

Adjust the timing of the signal of selected antenna collection.

16, a kind of antenna system, this antenna system comprises:

Aerial array;

Switching matrix, it links to each other with this aerial array, and is suitable for selected antenna is couple to a plurality of switching outputs;

Radio module, it links to each other with the first switching output, and is suitable for received RF signal;

Measurement module, it links to each other with this radio module, and is suitable for measuring the feature of the radiofrequency signal that this radio module receives; And

Control module, it is suitable for this switching matrix is controlled to be couple to the first switching output with will expecting antenna selectivity, and receive the feature that records of the radiofrequency signal that receives by selected antenna, this control module continues to select and receive measured value from a plurality of antennas of desired amt, measurement set with these a plurality of antennas is combined into a plurality of measurement in a closed series values then, and provides independently communication stream from selected combination of antennas to receiver based on these measurement in a closed series values.

17, antenna system according to claim 16, wherein this radiofrequency signal is an orthogonal frequency-division multiplex singal.

18, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprise the synchronizing signal measured in this signal degree of correlation to known synchronization signal.

19, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprises that synchronizing signal is to the degree of correlation of known synchronization signal in the measuring-signal.

20, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprises the error vector measurement.

21, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprises the measurement signal to noise ratio.

22, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprise measuring carries the letter ratio.

23, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprises the signal fadeout measurement.

24, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprises the phase place of measuring this radio signal.

25, antenna system according to claim 16, the step of wherein measuring characteristics of radio signals comprises the timing of measuring this radio signal.

26, a kind of method of from aerial array, selecting the antenna collection, this method may further comprise the steps:

Select the antenna in the aerial array;

The characteristics of radio signals that measurement receives at selected antenna place;

Expectation number of antennas in this array is repeated to select and measure;

The measurement set of selected antenna is combined into a plurality of measurement in a closed series values;

Based on these measurement in a closed series values combination of antennas is sorted; And

Select combination of antennas, therefore the independent communication stream that is combined to receiver from described is provided.

27, method according to claim 26, wherein signal receiver is an orthogonal frequency-division multiplex singal.

28, method according to claim 26, the step of wherein measuring characteristics of radio signals comprise the synchronizing signal measured in this signal degree of correlation to known synchronization signal.

29, method according to claim 26, the step of wherein measuring characteristics of radio signals comprises that the signal to receiving from two or more antennas makes up, and measures synchronizing signal in the composite signal then to the degree of correlation of known synchronization signal.

30, method according to claim 26, the step of wherein measuring characteristics of radio signals comprises the error vector measurement.

31, method according to claim 26, the step of wherein measuring characteristics of radio signals comprises the measurement signal to noise ratio.

32, method according to claim 26, the step of wherein measuring characteristics of radio signals comprise measuring carries the letter ratio.

33, method according to claim 26, the step of wherein measuring characteristics of radio signals comprises the signal fadeout measurement.

34, method according to claim 26, this method is further comprising the steps of:

Determine the phase place of the signal that receives from the antenna of desired amt; And

Adjust the phase place of the signal of selected antenna collection.

35, method according to claim 26, this method is further comprising the steps of:

Determine the timing of the signal that receives from the antenna of desired amt; And

Adjust the timing of the signal of selected antenna collection.

36, a kind of antenna system, this antenna system comprises:

Aerial array;

Switching matrix, it links to each other with this aerial array, and is suitable for selected antenna is couple to a plurality of switching outputs;

Radio module, it links to each other with the first switching output, and is suitable for received RF signal;

Measurement module, it links to each other with this radio module, and is suitable for measuring the feature of the radiofrequency signal that this radio module receives; And

Control module, it is suitable for this switching matrix is controlled to be couple to the first switching output with will expecting antenna selectivity, and receive the feature that records of the radiofrequency signal that receives by selected antenna, this control module continues to select and receive measured value from these a plurality of antennas of desired amt, measurement set with these a plurality of antennas is combined into a plurality of measurement in a closed series values then, and provides independent communication stream based on these measurement in a closed series values from selected day alignment receiver.

37, antenna system according to claim 36, wherein said independent communication stream is baseband signal.

38, antenna system according to claim 36, wherein said independent communication stream is the RF signal.

39, antenna system according to claim 36, wherein said independent communication stream is frequency-region signal.

40, a kind of method of from aerial array, selecting the antenna collection, this method may further comprise the steps:

Select the antenna in the aerial array;

The characteristics of radio signals that measurement receives at selected antenna place;

Antenna to the desired amt in this array repeats to select and measure;

The measurement set of selected antenna is combined into a plurality of measurement in a closed series values;

Based on these measurement in a closed series values combination of antennas is sorted; And

Select combination of antennas, therefore provide independent communication stream to receiver.

41, according to the described method of claim 40, the step that wherein provides independent communication to flow comprises provides baseband signal.

42, according to the described method of claim 40, the step that wherein provides independent communication to flow comprises provides RF signal.

43, according to the described method of claim 40, the step that wherein provides independent communication to flow comprises provides frequency-region signal.

Images