CN1242649A - Method and apparatus to reduce transmitter overload in transmit scanning receiver - Google Patents
Method and apparatus to reduce transmitter overload in transmit scanning receiver Download PDFInfo
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- CN1242649A CN1242649A CN 99106474 CN99106474A CN1242649A CN 1242649 A CN1242649 A CN 1242649A CN 99106474 CN99106474 CN 99106474 CN 99106474 A CN99106474 A CN 99106474A CN 1242649 A CN1242649 A CN 1242649A
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Abstract
Provided is a communication system which reduce transmitter overload in a transmit scanning receiver by reducing transmitter signals which are emitted from a overload transmitter and received by a transmit scanning receiver. Before a transmition, a sample of transmitter signal to be emitted is obtained from a transmitter. After the transmitter signal is emitted and then received by a transmit scanning receiver, the sample is used to reduce transmitter signals in a transmit scanning receiver. Therefor, the sample is delayed, adjusted and combined with transmitter signal. Furthermore, it is achieved to involve continuous cancellation levels of parallel coupling path to provide more depression on transmitter signals in transmit scanning path.
Description
The present invention relates to communication, relate in particular to the method and apparatus of the transmitter overload that lowers transmit scanning receiver.
Transmit scanning receiver for transmitter is generally operational on the tranmitting frequency of this transmitter and near the transmitter other.Transmit scanning receiver scanning just is being operated near other transmitters of tranmitting frequency.By near the tranmitting frequency of transmitter scanning, transmit scanning receiver can be used in to its transmitter and finds out the tranmitting frequency of not used by other transmitters.Because transmit scanning receiver generally is in close proximity to transmitter, so may hinder the ability that transmit scanning receiver scans this tranmitting frequency from the transmission of this transmitter.For example, generally comprise the front end of transmit scanning receiver of initialize signal processing unit of transmit scanning receiver owing to may transship from the higher relatively amplitude or the power level of transmitter transmission.In the transmit scanning receiver of overload, these transmission from transmitter cause in the transmit scanning receiver front end and produce spurious signal, therefore make transmit scanning receiver can not scan other tranmitting frequency effectively.In order to prevent the transmit scanning receiver overload, existing system requirement transmitter when transmit scanning receiver scans stops emission.Yet, when transmit scanning receiver scans, require transmitter to stop emission and can cause service disruption.For example, when the transmitter that is sending transmission with particular transmit frequency when this frequency runs into an interference signal, transmitter may be attempted to jump to and is used for sending transmission on another transmitted frequency.But if transmitter must stop emission to allow acceptable tranmitting frequency of transmit scanning receiver scanning, then service disruption may take place.
Therefore, need the transmitter overload that a system can lower transmit scanning receiver.
The present invention is by lowering from the emission of overload transmitter and transmitter overload lowered transmit scanning receiver by the transmitter signal that transmit scanning receiver receives.Before transmission, obtain the sample of a transmitter signal that will be launched from transmitter.After transmitter signal was launched and is launched the scanning radio reception, this sample was used to lower the transmitter signal at transmit scanning receiver.For this reason, this sample is delayed, is conditioned and makes up with transmitter signal.In certain embodiments, before transmission, obtain a part of transmitter signal and be placed on the coupling path from the transmission path of transmitter.Transmitter signal on the coupling path be conditioned and be injected on the emission scan path of transmit scanning receiver with by the transmitter emission and be launched the transmitter signal combination that scanning radio receives.Delay unit in coupling path be used to regulate delay on the coupling path with correspondence by the transmitter emission and be launched the delay of the transmitter signal experience that scanning radio receives subsequently.Amplitude on the coupling path and phase regulator amplitude and phase adjusted at the transmitter signal on the coupling path to lower the transmitter signal on the emission scan path.In order to improve the attenuating of transmitter signal on the emission scan path, can carry out the measurement of transmitter signal on the emission scan path at least, and this measurement can be used to regulate the phase place of transmitter signal on the coupling path and/or amplitude to lower the level of transmitter signal on the emission scan path.In addition, can realize comprising the continuous cancellation stage in Parallel coupled path to be provided at the more inhibition of transmitter signal on the emission scan path.
According to following detailed and with reference to accompanying drawing, it is more obvious that other aspects of the present invention and advantage can become, wherein:
Fig. 1 illustrates the general block diagram of system embodiment that a principle according to the present invention is used to lower the transmitter overload of transmit scanning receiver; And
Fig. 2 illustrates an embodiment more specifically who lowers system according to the transmitter overload of Fig. 1 of principle of the present invention.
The explanation embodiment that lowers the method and apparatus of transmitter overload in the transmit scanning receiver according to principle of the present invention is described below.The cancellation stage 10a that transmits shown in Fig. 1 is included in the coupling path 11 between the emission scan RX path 16 of transmit scanning receiver 17 of the transmission path 12 of transmitter 13 and receiver 18.In this example, more detailed for the front end that the transmitter and receiver parts 13 that are used for base station 14 shown in the present and 18 are described than the remainder of base station 14.For the purpose of discussing, transmitter 13 and receiver 18 simply illustrate as square frame, but should be appreciated that transmitter 13 and receiver 18 can comprise a plurality of radio stations of transmitting and receiving signal and can be according to the structure of base station 14 with different configuration arrangements.Transmitter 13 and receiver 18 are described to comprise the various piece of base station 14 front ends.For example, transmission path 12 is described to the part of transmitter 13, and the emission scan path is described to the part of transmit scanning receiver.In addition, the transmit scanning receiver 17 that illustrates is as one in the receiver 18, and should be appreciated that according to using transmit scanning receiver and can adopt special-purpose radio station or realize in existing receiver circuit.
In this embodiment, coupler 20 is coupled or the coupling path 11 of the sample of the transmitter signal on the transmission path 12 to cancellation stage 10a is provided.In this specific embodiment, coupler 20 is brought into low-loss (approximately 0.5dB) on the transmission path 12, but may bring the loss of 10-20dB into be coupled on the coupling path 11 transmitter signal.Delay 24 in the coupling path 11 postpone on coupling path 11 transmitter signal with from transmission path 12 emissions and in the emission scan path delay of the 16 transmitter signals experience that receive consistent.In Fig. 1, postpone 24 reflected by through emission filter 26, by 30 the wireless transmission from antenna 28 to antenna, through emission scan filter 32 to the delay of the transmitter signal experience in emission scan path 16 and poor by the relative delay the delay of transmitter signal experience on the coupling path 11.The delay of the transmitter signal on the coupling path 11 does not need accurately to be matched with the delay by the transmitter signal experience that is transmitted into the emission scan path.Yet, as will be understood by those skilled in the art that should be mated by the delay of two groups of transmitter signal experience, the appropriate section of transmitter signal can make up with transmitter signal on attenuating or the inhibition emission scan path 16 with a kind of mode like this.For example postponing difference may be about picosecond magnitude.Each grade 10n can provide the counteracting of about same amount, 20-30dB for example, but when transmitter signal very little as-during 80dBm, offset and become very little.
Phase place and amplitude that phase place and amplitude regulator 34 regulated the transmitter signal on the coupling paths 11, and coupler 36 from coupling path 11 inject transmitter signals to emission scan path 16 to lower or to suppress transmitter signal on the emission scan path 16.By suitably regulating the phase place and/or the amplitude of the transmitter signal of coupling, the transmitter signal of coupling will be with the combination of the transmitter signal on a kind of mode and the emission scan path 16 to lower the transmitter signal from emission scan path 16.According to specific application and specific design, this scheme can lower the 3dB-50dB (generally being 10-40dB) of transmitter signal on the emission scan path 16.The attenuation major part of the transmitter signal on the emission scan path 16 depends at transmitter signal on the emission scan path 16 with in the phase place of the appropriate section of transmitter signal on the coupling path 11 and the difference between the amplitude.In order to increase attenuation, the amplitude difference between the transmitter signal on emission scan path 16 and the coupling path 11 should be zero, and the phase difference between them should be 180 °.2dB amplitude difference between the transmitter signal that use receives and the transmitter signal of coupling and 175-185 ° phase difference can obtain the effective counteracting of transmitter signal.In order further to improve the counteracting of the transmitter signal on the emission scan path 16, can use continuous cancellation stage 10n that the inhibition of the transmitter signal on the emission scan path 16 is provided in addition.By suppressing the overload transmitter signal on the emission scan path 16, transmitter 13 can be launched transmitter signal continuously, simultaneously transmit scanning receiver 17 scanning tranmitting frequencies.
In order in different embodiment, to improve the attenuating of the overload transmitter signal on the emission scan path 16, control circuit 38 can before the cancellation stage 10a-n and/or measure the amplitude of overload transmitter signal and/or phase place afterwards and regulate the amplitude of the transmitter signal on the coupling path 11 and/or phase place to improve the counteracting of transmitter signal on the emission scan path 16.Control circuit 38 also can be measured the phase place of the transmitter signal on the coupling path 11 and/or phase place that amplitude is regulated transmitter signal on the coupling path 11 and/or amplitude to improve the counteracting of transmitter signal on the emission scan path 16.Control circuit 38 by attempting to regulate the transmitter signal on the coupling path 11 phase place and/or amplitude with the counteracting of transmitter signal on the emission scan path 16 that reaches phase difference 180 ° of the amplitude of transmitter signal on the emission scan path 16 and/or acquisition and transmitter signals and provide improvement.
Control circuit 38 shown in Figure 1 has some inputs, they can be used in measurement in the phase place that transmits on the coupling path 11 and/or amplitude, offsetting before in the phase place and/or the amplitude of overload transmitter signal on the emission scan path 16, offsetting after phase place and/or the amplitude or their combination of signal on emission scan RX path 16.The transmitter overload embodiment that lowers system can comprise control circuit in accordance with the principles of the present invention, in these parameters of this circuit measuring any one, the combination of different parameter or these or different parameters with the amplitude of regulating transmitter signal on the coupling path 11 and/or phase place to improve the inhibition of overload transmitter signal.Like this, can use feedback and/or feed-forward information to regulate the amplitude of transmitter signal of coupling and/or phase place and further lower by using control circuit because the overload of the transmit scanning receiver that causes from the transmitter signal of the transceiver of same base.
Control circuit 38 can use one, some or all of these input parameters as the input to question blank, and this table provides suitable phase place and/or the gain for transmitter signal on the coupling path 11.On the other hand, control circuit 38 can use input parameter to determine required phase place and/or amplitude or be used for the phase place and/or the amplitude adjusted of transmitter signal on the coupling path 11.For example, the amplitude of the transmitter signal on coupling path 11 and emission scan path 16 and/or phase place can be measured and compare to control circuit 38 so that amplitude and/or phase information to be provided.In addition, the amplitude that transmits that can measure simply on the emission scan path 16 of control circuit 11 arrives adjuster 34 to adjuster 34 and/or measurand transmitter phase difference between signals so that phase information to be provided so that amplitude information to be provided.In another approach, before offsetting, measure the amplitude of the transmitter signal on the emission scan path 16 to be provided at the amplitude adjusted of the transmitter signal on the coupling path 11.
In additive method, the power level of control circuit 11 monitoring transmitter signal on the emission scan path 16 after offsetting, and response is the attenuating in the power level of overload transmitter signal on the emission scan path 16 after offsetting, and systematically changes phase place and/or amplitude adjusted.The difference configuration and the variation of control circuit 38 are possible.In addition, use the continuous cancellation stage 10n of control circuit may further suppress to transship transmitter signal, and different cancellation stage can be measured different parameters and have different configurations.
Among the embodiment of Fig. 1, cancellation stage 10a-n is coupling between the emission scan path 16 of the transmission path 12 of transmitter 13 of same base 14 and receiver 18.Base station 14 comprises antenna 28 and 30 so that antenna diversity to be provided, and emission scan 16 is coupled to antenna 30 as shown.The present invention can use with base station, transceiver or emittor/receiver equipment, and transmit scanning receiver uses the antenna of a special use or shares one or more antennas here.As one of ordinary skill will be appreciated, the present invention can use together with different configurations, and the transmitter signal from particular transmitter is suppressed in the receiver path by obtained the sample of a transmitter signal before transmission here.
In this embodiment, radio frequency (RF) signal is received by antenna 28 and 30.At the signal that receives on the antenna 28 through the RX filter 42 of duplexer 44 and the low noise amplifier 48 on first RX path 46 and the remainder of receiver circuit 18.According to the position (current location is the emission scan pattern) of switch 50 in this specific embodiment, the signal that receives at antenna 30 passes through the emission filter 32 of duplexer 56 to emission scan path 16.Emission filter 32 allows transmitter band by emission scan path 16.On emission scan path 16, grade 10a-n that is cancelled as discussed above suppresses from the transmitter signal of transmitter 13.Then, comprise from the transmitter signal of the inhibition of transmitter 13 with from the transmitter signal of the transmitter signal of other transmitter (not shown) and be provided to low noise amplifier 52.This point at this specific embodiment, transmitter signal (transmitter signal of overload) from transmitter 13 should be suppressed, and is main as the transmitter signal from other base station (not shown) and the remainder that is sent to receiver 18 is used for the channel usage analysis from the transmitter signal of other transmitter (not shown).
On the other hand, in this specific embodiment, if switch 50 is connected to second RX path 54, then base station 40 is in the diversity receiver pattern and in the emission scan pattern, and the signal that receives at antenna 30 is through the receiving filter 57 of duplexer 56 and to the second receiver path 54.Low noise amplifier 58 in second RX path 54 amplifies the signal that receives and the remainder of this signal to receiver 18 is provided.
Fig. 2 illustrates the more specifically embodiment of the cancellation stage 10a of a Fig. 1.In this specific embodiment, control circuit 38 (Fig. 1) comprises S meter (RSSI) 60 and 62, phase detectors 64 and the controller 66 of reception.RSSI 60 and 62 provide and the proportional signal of power level of the transmitter signal measured to controller 66.RSSI 60 is coupled out a part of transmitter signal on the emission scan path 16 by using coupler 36, in intensity or the power level of measuring the transmitter signal on the emission scan path 16 before the cancellation stage 10a.RSSI 62 is coupled out a part of transmitter signal on the path 16 by using coupler 37, measures the intensity of the transmitter signal on the emission scan path 16 after cancellation stage 10a.In this specific embodiment, after adjuster 34, measure transmitter signal on the coupling path 11 (also can before adjuster 34 measurand transmitter signal), and before offsetting and measure transmitter signal on the emission scan path 16 afterwards.The coupling pattern of transmitter signal on transmitter signal on the phase detectors 64 reception emission scan paths 16 and the coupling path 11, and measure the phase difference between the transmitter signal on transmit on the coupling path 11 machine signal and the emission scan path 16.Phase detectors 64 provide phase information (it can be different from simple phase difference) to controller 66.Response is from RSSI 60 and 62 and the input of phase detectors 64, controller 66 provide amplitude and phase adjusted information to adjuster 34 with the amplitude that is adjusted in transmitter signal on the coupling path 11 and/or phase place to improve the inhibition of the overload transmitter signal on emission scan path 16.
In certain embodiments, controller 66 parts make and offset the output that occurs in coupler 36 according to providing amplitude information to be used to be adjusted in the amplitude of the transmitter signal on the coupling path 11 to adjuster 34 in the amplitude of transmitter signal on the emission scan path 16 before offsetting.Controller 66 is attempted to lower on the coupling path 11 amplitude difference between the transmitter signal on the transmitter signal and emission scan path 16.The amplitude difference of 2dB is acceptable between them.Controller 66 parts according to provide from the phase information of phase detectors 64 phase information to adjuster 34 to regulate the phase place of the transmitter signal on the coupling path 11, attempt to obtain on the transmitter signal of overload on the emission scan path 16 and the coupling path 11 180 ° phase difference between the transmitter signal.Owing to obtain between the transmitter signal 180 ° phase difference, on the emission scan path, provide the counteracting of improved overload transmitter signal in 180 ° of summations of the transmitter signal of the output of coupler 36.Yet according to specific configuration, not requiring between two kinds of patterns that transmit has 180 ° of phase differences, and for example 175-185 ° phase difference is acceptable.
Different controlling schemes also may obtain to offset.For example, the phase place of the transmitter signal of the overload on emission scan path 16 and/or amplitude can compare the starting point of offsetting as obtaining with the phase place and the amplitude of the transmitter signal that is coupled.After cancellation stage 10a, the measurement of the amplitude of the transmitter signal of overload or power level can be used for the phase place and/or the amplitude adjusted of the transmitter signal of accurate tuning coupling on emission scan path 16.In using the system of a plurality of cancellation stage 10n, RSSI 62 can be arranged in transmit scanning receiver 19 with provide this amplitude information to one of cancellation stage 10a-n, all or some.
Except the foregoing description, the another kind of the bucking-out system that transmits in accordance with the principles of the present invention configuration is possible, and its omits and/or adds upper-part and/or use the modification or the part of described bucking-out system.For example, transmitter signal has been described as being coupled to the emission scan path to lower transmitter signal there from the transmission path coupling of transmitter 13 and from coupling path.The situation that term coupling comprises be transmitter signal on transmission path by or separately from the transmission path sampling, and transmitter signal is from transmission path sampling and/or reproduced and inject, add or be combined to the emission scan path on coupling path.In certain embodiments, the transmitter signal of overload and the amplitude of the transmitter signal of coupling can be measured and relatively so that the amplitude adjusted of coupling transmitter signal to be provided, and amplitude can be used to provide phase adjusted information to the level of adjuster 34 with the transmitter signal that is reduced in the overload after the counteracting after the counteracting of the transmitter signal of overload.On the other hand, in a relative simple embodiment, the amplitude of the transmitter signal of the overload after offsetting only is the input of controller 66, the phase place and/or the amplitude of the transmitter signal of coupling regulated on this controller system ground, attempts to reduce the amplitude of transmitter signal on the emission scan path 16.
In addition, used the various configurations of different parts to describe cancellation stage 10a-n, but the benefit of this invention as one of ordinary skill will be appreciated should be appreciated that transmit scanning receiver bucking-out system and its part can use the arrangement realization of application-specific integrated circuit (ASIC), software-driven treatment circuit, firmware or other discreet components.Like this, though have control corresponding and measuring circuit in each cancellation stage shown in the embodiment of explanation, the control circuit and the measuring circuit that are used for cancellation stage 10a-n can be the parts of receiver circuit 18.Equally, shown in each cancellation stage have identical control circuit 38 (Fig. 1), but each cancellation stage can differently be controlled, and for example regulates the phase place and/or the amplitude of the transmitter signal of coupling by measuring different signals.In addition, control circuit can realize in having the circuit of feedback control loop, and this feedback control loop iteration is carried out phase place and/or amplitude adjusted so that improved counteracting to be provided.Above-described only is the explanation that the principle of the invention is used.One of ordinary skill in the art will readily recognize that can make for the present invention these and various other modification and need not strictly observe the Demonstration Application of explanation and the description here, and do not deviate from the spirit and scope of the present invention.
Claims (11)
1. a method of operating communication system is used to lower the transmitter signal of launching and be launched the scanning radio reception from transmitter, and described method feature is step:
Obtain the transmitter signal that will be launched from the transmission path of described transmitter; And
The transmitter signal that uses described acquisition is to lower on the emission scan path of transmit scanning receiver from described transmitter emission and the described transmitter signal that received by described transmit scanning receiver.
2. the method for claim 1 is characterized in that described acquisition step comprises:
The described transmitter signal that will be launched from the coupling of described transmission path is to coupling path.
3. method as claimed in claim 2 is characterized in that step:
Postpone the delay that the described transmitter signal on the described coupling path is experienced from described transmission path to described emission scan path by the described transmitter signal from described transmitter emission with reflection.
4. method as claimed in claim 2 is characterized in that step:
Be adjusted in the amplitude of the described transmitter signal on the described coupling path.
5. method as claimed in claim 4 is characterized in that step:
Measurement from the power level of the described transmitter signal of described transmitter emission to regulate the amplitude of described described transmitter signal on coupling path.
6. method as claimed in claim 2 is characterized in that step:
Be adjusted in the phase place of the described transmitter signal on the described coupling path.
7. method as claimed in claim 2 is characterized in that described use step comprises:
Be coupled described transmitter signal on the described coupling path to the described emission scan path to suppress from the described transmitter signal of described transmitter emission.
8. communication system, comprise that one has the transmitter of the transmission path that transmits transmitter signal and comprises a transmit scanning receiver with transmission from the emission scan path of the transmitter signal of described transmitter emission, described system comprises a cancellation stage, it is characterized in that:
First coupler is coupled to the described transmission path of described transmitter, and its coupling is from the transmitter signal of the described transmission path path to coupling;
A delay unit, be connected on the path of described coupling transmitter signal with the described coupling on the path that postpones described coupling with reflection by the delay that described transmitter signal was experienced that is transmitted into described emission scan path from described transmission path;
Phase place and amplitude regulator are connected on the described coupling path so that to phase place and the amplitude of small part according to the transmitter signal of the described coupling of described transmitter signal level adjustment on described emission scan path; And
Second coupler, the transmitter signal of the described coupling on the described emission scan of coupling path on the path of described coupling is to lower the described transmitter signal of launching from described transmitter on described emission scan path.
9. system as claimed in claim 8 is characterized in that continuous cancellation stage is coupling between described transmission path and the described emission scan path concurrently.
10. system as claimed in claim 8, the amplitude that it is characterized in that described phase place and the described transmitter signal of decay regulator response on the path of measuring and adjusting in described coupling of the described transmitter signal of launching from described transmitter on the described emission scan path, and after an output of described second coupler was lowered, response was in the measurement of the described transmitter signal on the described coupling path with in the described phase place of the described transmitter signal of measuring and adjusting on described coupling path of the above transmitter signal of described emission scan path at described transmitter signal.
11. system as claimed in claim 8 is characterized in that described transmitter and described transmit scanning receiver are in same base station.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99106474 CN1242649A (en) | 1998-05-13 | 1999-05-12 | Method and apparatus to reduce transmitter overload in transmit scanning receiver |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US076,951 | 1998-05-13 | ||
| CN 99106474 CN1242649A (en) | 1998-05-13 | 1999-05-12 | Method and apparatus to reduce transmitter overload in transmit scanning receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1242649A true CN1242649A (en) | 2000-01-26 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99106474 Pending CN1242649A (en) | 1998-05-13 | 1999-05-12 | Method and apparatus to reduce transmitter overload in transmit scanning receiver |
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| Country | Link |
|---|---|
| CN (1) | CN1242649A (en) |
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1999
- 1999-05-12 CN CN 99106474 patent/CN1242649A/en active Pending
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