KR100830566B1 - Reception of signals in a device comprising a transmitter - Google Patents

Abstract

The invention relates to an apparatus (1) comprising a communication system transmitter (30) for transmitting a signal over an air interface in a first frequency band. The apparatus further includes a receiver 10 for receiving signals over the air interface in the second frequency band. The GPS receiver 10 includes an attenuator 13 for attenuating signals received by the receiver 10. The apparatus also sets the attenuation applied to the signals received by the receiver 10 by the attenuator 13 to a higher value when the communication system transmitter 30 transmits the signals at a power level exceeding a specified value. And a controller 50 for setting the attenuation applied to the signals received by the receiver 10 by the attenuator 13 to a lower value when the communication system transmitter 30 does not transmit a signal. . The invention also relates to a corresponding method.

Description

Reception of signals in a device comprising a transmitter

The present invention relates to an apparatus comprising a communication system transmitter for transmitting signals over an air interface in a first frequency band and a receiver for receiving signals at an air interface in a second frequency band. The invention also relates to a method for improving the performance of a receiver coupled to a single device comprising a communication system transmitter.

Communication system transmitters for transmitting signals over the air interface are known, for example, Global System for Mobile communication (GSM), US Time Division Multiple Access or IS-136 (US-TDMA), Code Division Multiple Access (CDMA) Or there are devices that enable the operation of devices operating with a communication network as a wideband CDMA (WCDMA) communication device. Furthermore, a receiver operating in a frequency band different from such a communication system is, for example, such as a global positioning system (GPS) included in a GPS system. Communication system transmitters operating in the first frequency band and receivers operating in the second frequency band may also be implemented in a single device, such as a mobile phone.

However, the receiver may not operate well during the time that the communication system transmitter implemented in the same device operates. In particular, when the communication system transmitter in the first frequency band generates wideband noise in the second frequency band, this wideband noise degrades the receiver's ability to receive signals in the second frequency band.

For example, in a GSM system, several GPS satellites orbiting around the earth transmit signals that are received and evaluated by the GPS receiver. All GPS satellites use 1575.42 MHz and 1227.60 MHz, respectively, with the same carrier frequencies L1 and L2. These carrier frequencies L1 and L2 are illustrated in FIG. 1. After a phase shift of 90 degrees, the sinusoidal L1 carrier signal is BPSK modulated by each satellite using a different coarse acquisition (C / A) known to the receiver. Therefore, channels for different transmissions are obtained by different satellites. The C / A code spreads the spectrum over a bandwidth of 1.023 MHz, which is a pseudorandom noise sequence repeated every 1023 chips, with each epoch of the code being 1 ms. The term chip is used to distinguish bits of a modulation code from data bits. As such, the L1 carrier signal is BPSK modulated by a P-code after 3 dB attenuation, and the L2 carrier signal is attenuated by the same precision code before attenuating 6 dB and then BPSK modulated. do. Prior to transmission, the two differently modulated portions of the L1 carrier signal are summed again. The current L2 carrier signal only carries a P-code. P-codes are much longer than C / A codes. The chip rate of the P-code is 10.23 MHz, which repeats every seven days. P-codes are also called P (Y) -codes because they are currently encrypted and encrypted. Decryption keys for using P (Y) -code are classified and civil users cannot access the decryption key. Therefore, only L1 carrier C / A code is available for general GPS receivers.

Before the C / A-code and P (Y) -code are modulated with the L1 and L2 signals, the navigation data bits have a bitrate of 50 bits / second and use modulo-2 addition with a modulo-2 addition. / A-code and P (Y) -code are added. The navigation information making up the data sequence can be evaluated, for example, to determine the location of an individual receiver. The L1 signal received at the receiver is further modulated because of the Doppler effect and possibly other higher order dynamic stresses.

The reception bandwidth of the GPS receiver receiving the modulated satellite signals is related to the reception code. For example, if GPS is based on the L1 carrier C / A-code, the signal requires a frequency band of 1575.42 MHz +/- 5 MHz. If a receiver capable of using P-codes is used, the reception band of the GPS receiver is wider, possibly corresponding to a frequency band of 1575.42 MHz +/- 24 MHz. Since the actual GPS reception bandwidth used is more relevant to the actual device, the previously mentioned bandwidths are provided for illustrative purposes. Thus, the mentioned GPS bandwidth will be used as described below only in an illustrative sense.

The GPS standard is currently being modernized. One of the main elements of modernization includes two new navigation signals, which are used for civil use in addition to the L1-C / A-code at 1575.42 MHz, the existing civil service broadcast. May be provided.

The first of these novel signals is a C / A-code located at 1227.60 MHz, i.e., this signal is modulated onto the L2 carrier frequency and may be commonly used in applications where stability is not very important. The novel civician signal in L2 is called "L2CS", which is a ranging code equivalent to 1.023 Mcps (number of megachips per second) with time division multiplexing of two half rate codes. characterized by a ranging code. The L2CS signal will be BPSK modulated onto the L2 carrier along the P (Y) -code. This C / A-code will be available with the launch of the first GPS block IIF satellite, which will be serviced in 2003.

The second of these new signals will use L5, the third carrier frequency located at 1176.45 MHz. The L5 signal carrier frequency is modulated by a C / A-code, which is more specifically modulated by a CL code of 767,250 chips and a CM code of 10,230 chips. The L5 signal will provide a ranging code of 10.23 Mcps, which is expected to improve the cross correlation property. The L5 signal will be based on the message. This signal consists of an I (In-phase) channel carrying 10-symbols of Neumann / Hoffmann encoding and a Q (Quadrature (orthogonal phase) channel carrying 20-symbols of Neumann / Hoffmann encoding). Will include. I and Q channels are orthogonally modulated on the L5 carrier. The L5 signal enters a globally protected frequency band for aeronautical radionavigation and will therefore be protected for life critical applications. In addition, this causes no interference to existing systems. Therefore, without the need to modify existing systems, adding L5 signals could transform GPS into a more robust radio navigation service for many navigation applications, as well as for all ground-based users. will be. Ground-based users include maritime, maritime, railroad, land surface, and navigational users. The new L5 signal will be available in GPS block IIF satellites scheduled for launch in 2005.

At the current GPS satellite replenishment rate, all three civil signals L1-C / A, L2-C / A, and L5 will be available for the first time around 2010, Perhaps by 2013 it will be fully operational.

If no measurement is made, the signal-to-noise ratio (SNR) of the GPS signal received by the GPS receiver is determined by a single slot transmission (TX) transmission for transmission by a GSM transmitter mounted on the same device. It is estimated that the degradation is about 2 dB if using the) mode and about 3 dB if the GSM transmitter mounted on the same device uses the dual slot transmission (TX) mode for transmission.

A system widely referred to as the Personal Communication System (PCS), such as the GSM1900, a specific communication system that operates in the 1900 band, and a system widely referred to as the Digital Communication System (DCS), such as the GSM1800, operating in the 1800 band A particular communication system will generate broadband noise in the GPS L1 band of 1575.42 MHz +/- 5 MHz when GPS with C / A-code is used. If new L2 and L5 frequency GPS signals are used, GPS signals using lower frequencies, such as GSM900 and GSM800, will cause the same broadband noise problem as L1 GPS signals are used for GSM1800.

The same problem can also occur if a Galileo receiver is used instead of a GPS receiver. Galileo is a European satellite positioning system whose commercial operation is expected to begin in 2008. Galileo contains 30 satellites, which are distributed in three circular orbits to cover the entire surface of the earth. Satellites can also be supported by a worldwide network of ground stations. Galileo is expected to provide 10 navigation signals operating in right hand circular polarization (RHCP), whose frequency ranges are 1164-1215 MHz when using carrier signals E5a and E5b, and the carrier signal E6 It is 1215-1300 MHz when used and 1559-1592 MHz when the carrier signals E2-L1-E1 are used. Similar to the GPS case, the carrier frequencies of E5a, E5b, E6 and E2-L1-E1 will be modulated using several PRN codes and data to spread the spectrum. Therefore, GSM transmitters will generate the same wideband interference in the frequency bands employed by Galileo.

Obviously, other combinations of communication system transmitter and receiver implemented within a single device also face the same problem.

In US Pat. No. 6,107,960, a configuration is proposed where control signals are transmitted from the communication transceiver to the satellite positioning system receiver when the communication transceiver transmits data at a high power level over the communication link. The control signal causes the satellite positioning system signals from the satellites to be blocked by the receiving circuits of the satellite positioning system receiver or disregarded by the processing circuits of the satellite positioning system receiver. Be sure to

In devices using GPS receivers and GSM transceivers, if GPS signals are interrupted or ignored while the GSM transceiver is transmitting at a high power level, the result is that, in the case of single slot GSM, GPS information is theoretically lost by 0.577 ms for 4.616 ms. Obtained, which corresponds to a GPS sensitivity loss of 0.6 dB. In the case of dual slot GSM, this disturbance or disregard resulted in the loss of GPS information by 1.154 ms for 4.616 ms, which corresponds to a GPS sensitivity loss of 1.2 dB.

There has been further proposed a method for improving the signal-to-noise ratio (SNR) of received satellite signals by adding an external notch-filter to the transmission path of a communication system transmitter. The notch-filter arranged after the power amplifier of the transmission path attenuates the pass band frequency range for passing only the frequency bands required by the communication system and the frequencies required by the satellite positioning system. To have a stop band frequency range.

For PCS and DCS, the passband frequency range of the notch-filter should be 1710 MHz to 1910 MHz, and the cutoff band frequency range should be 1558.42 MHz to 1580.43 MHz when GPS is used as the satellite positioning system. In order to improve the signal-to-noise ratio (SNR) of the received GPS signals to a useful level, a very large attenuation must be made in the cutoff band. However, applying high attenuation also increases the insertion loss of the notch-filter in the pass band of the filter. If such insertion loss occurs after the power amplifier, a larger output power must be consumed by the power amplifier, which increases the current consumption.

If the signal-to-noise ratio (SNR) of the GPS is improved to the desired level, corresponding to a degradation of 0.5 dB, it has been measured that the antenna isolation required for single slot GSM corresponds to about 10 dB. In the GSM1800 transmit path, an external GPS band attenuator of 30dB must be added to achieve the same level of 0.5dB degradation. In dual slot GSM, the desired attenuation is higher.

The insertion loss of a GPS notch-filter with GPS band attenuation of 30 dB will be between 0.7 dB and 1.0 dB. An insertion loss of 0.7 dB to 1.0 dB increases the power amplifier's current consumption by about 20% compared to the absence of insertion loss.

Therefore, the solution using the notch-filter has disadvantages because of the need for additional elements and the 20% increase in current consumption of the power amplifier. Therefore, there is too much cost to improve the GPS signal-to-noise ratio (SNR) by only 1.5 dB.

It is an object of the present invention to provide an alternative to existing solutions for improving the performance of a receiver while a communication system transmitter mounted on the same device as the receiver performs a transmission operation.

On the other hand, two devices are proposed that include a communication system transmitter for transmitting signals over an air interface in a first frequency band. The communication system transmitter may include a variable amplifier for amplifying signals to be transmitted by the communication system transmitter at varying power levels. The proposed apparatus also includes a receiver for receiving signals in the second frequency band. The receiver includes an attenuator for attenuating the signals received by the receiver. The proposed apparatus also provides a higher value for the attenuation applied to the signals received by the receiver by the attenuator when the communication system transmitter transmits signals at a power level exceeding a specified value. And a controller configured to set attenuation applied to signals received by the receiver by the attenuator to a lower value when the communication system transmitter does not transmit a signal. . The proposed attenuation is set by the controller to be only one attenuation or additional attenuation applied to the signal by the receiver.

On the other hand, a method for improving the performance of a receiver is proposed. The receiver is coupled to a single device comprising a communication system transmitter for transmitting signals over the air interface in the first frequency band and a receiver for receiving signals over the air interface in the second frequency band. The proposed method attenuates the signals received by the receiver by the attenuator to a higher value when the communication system transmitter transmits signals at a power level exceeding a specified value, If not transmitting, attenuating the signals received by the receiver to a lower value.

It should be noted that, unless specifically stated otherwise, the term receiver refers to a receiver such as a receiver operating in a different frequency band than the communication system transmitter.

The present invention starts with the consideration that it is preferable for the performance of the receiver to receive a signal at a particularly low signal-to-noise ratio (SNR) for a short time interval rather than to receive the signal at all. For example, in the case of GPS, if there is no signal present in the GPS receiver, the receiver emulates that there is a very high attenuation fading around. The GPS receiver's performance on fading signals is a matter of mounting the device. The implementation determines how tracking and other algorithms work in the presence of very low GPS signal levels. Therefore, while the communication system transmitter of the apparatus transmits at a high power level, it is proposed to attenuate the incoming signal by applying a high attenuation to the signals received by the receiver to a level suitable for subsequent processing. On the other hand, if the communication system transmitter of the device does not transmit any signals or the signals being transmitted have a low power level, then the attenuation does not apply to the signals received by the receiver or a low attenuation applies, This is because the wideband noise level is low enough to evaluate the signals received by the receiver in this case.

It is an advantage of the present invention that the present invention presents an alternative to existing solutions.

In addition, an advantage of the present invention is that it is easy to mount. The proposed attenuation can be obtained by an external attenuator in the receiver chain of the receiver, or by the integrated Automatic Gain Control (AGC) function of the receiver chain of the receiver. For example, in a GPS receiver, this automatic gain control (AGC) function is already built in.

It is also an advantage of the present invention that it does not cause an increase in the current consumption in the power amplifier of the communication system transmitter.

It is also an advantage of the invention that the performance is better than the approach provided by US Pat. No. 6,107,960 as described above, since the approach according to the invention can be adapted to the individual operating conditions. In some cases, the signal arriving at the device may be so strong that it may have a sufficiently high signal-to-noise ratio (SNR) in spite of the generated wideband noise and may also be larger so that it can be evaluated within the receiver despite the applied attenuation. have. Therefore, in certain cases, the receiving operation by the receiver can be maintained while the transmitting operation by the communication system transmitter is performed, which causes attenuation of the signal received by the receiver, which operation is described in US Patent No. 6,107,960. It is not possible if the signal reception is completely blocked as provided by or if the received signal is simply ignored.

Preferred embodiments of the invention will be apparent from the dependent claims.

Attenuators can be implemented in a variety of ways, that is, they can be implemented as a single unit or distributed over several units.

For example, the attenuator may comprise a variable gain amplifier, which may be used exclusively for extra attenuation according to the present invention or in addition to automatic gain control in the prior art. Such a variable gain attenuator is preferably arranged after the first amplifier of the receiver chain of the receiver. If additional insertion loss occurs before the first amplifier, the sensitivity of the receiver is degraded, which is undesirable.

Further, the attenuator may be implemented by a low noise amplifier (LNA) of the receiver, for example, by using a gain step function of the low noise amplifier (LNA). This gain step function is used in cellular mobile phones to keep the receiver operating in linear mode when high level input signals are received.

Furthermore, the attenuator may comprise elements for reducing or blocking one or more operating voltages of the receiver element, for example performing such an operation on a low noise amplifier (LNA) or an operating voltage of the amplifier. . If no operating voltage is provided for certain receiver elements, very high attenuation can be obtained. However, it should be noted that if the first elements in the receiver chain of the receiver do not have a high gain, the noise value of the entire receiver may be rather high, which is not a desirable phenomenon.

The attenuator may also be an element capable of detuning an antenna coupled to a receiver for receiving a signal in a second frequency band.

In addition, the attenuator may include a variable amplifier of the receiver. The attenuation of the received signals can then be altered by changing at least some of the amplification factors of the amplification applied to the signals received by the variable amplifier.

The attenuator may apply the attenuation set to the received signal at the radio frequency. Alternatively or in addition, the attenuator may apply a set attenuation to the intermediate frequency signal, which is output by a converter element that converts the received radio frequency signal into an intermediate frequency signal. Further alternatively or in addition, the attenuator can apply a set attenuation on the baseband signal, which is provided by converting the intermediate frequency signal into a baseband signal.

In addition, the controller may be implemented in various ways, that is, implemented as a single unit, or may be distributed in several units.

The control unit may be located in a communication system section of a device that includes a communication system transmitter, or may be included in a receiver section of a device that includes a receiver. The control may also be located at least partially outside of both of these sections and / or distributed in both sections. The control unit may include, for example, at least a portion of the processor provided within the communication system section and at least a portion of the processor provided within the receiver section. For this purpose, the processors may be physically coupled, or the controller may determine appropriate attenuation by combining information from both processors. For example, such information may include the power level of all transmitted and received signals. If the receiver includes an AGC element, the control unit may also combine the information provided by the AGC element and the information provided from the communication system. The AGC element may indicate, for example, attenuation that is typically applied to signals received by the receiver. The control unit may also be mounted within the AGC element.

Furthermore, the attenuation applied from the attenuator can be controlled in various ways by the control element.

In a first possible embodiment of the present invention, the attenuation applied to the signals received by the present invention may have only one of two predetermined values. The first value, which is a low value, is used when the communication system transmitter does not transmit or uses an amplification factor lower than the predetermined value for transmission, and the second value, which is higher, is used when the communication system transmitter transmits at a power level above the predetermined value.

However, in the second preferred embodiment of the present invention, the attenuation of the signals received by the receiver is adapted to the individual transmission noise level. In particular, the higher the amplification applied to the signals to be transmitted by the communication system transmitter, the greater the attenuation applied to the signals received by the receiver. Therefore, it is possible to optimize exploitation of the received signals.

In the case of strong signals in the second frequency band reaching the device and in the case of rather small signals transmitted by the communication system transmitter, the signal-to-noise ratio (SNR) of the signal received by the receiver will still be high. In the case of a weak signal in the second frequency band reaching the device and in the case of a rather small signal received by the receiver, the signal-to-noise ratio (SNR) of the signal received by the receiver will be very low. The rather low attenuation applied to the received signals corresponding to the low amplification applied to the transmitted signals allows the receiver to process the received signal nevertheless with a high signal-to-noise ratio (SNR), because this signal The whole has a power level that is large enough to evaluate. However, a received signal with a low signal-to-noise ratio (SNR) cannot be processed at the receiver because this signal has a power level too low to be evaluated as a whole.

In the second embodiment of the present invention, the adjustment of the attenuation may be performed by predetermined steps or on a continuous scale. In particular, if an individual number of possible output power levels is used, for example if five possible output power levels are used, then a different attenuation value may be associated for each of these levels. Furthermore, as a certain low value, the increase in attenuation starting from zero, for example, can only be initiated at a certain minimum amplification factor. Below this minimum amplification factor, the resulting wideband noise may be considered to have no significant effect on the signal-to-noise ratio (SNR) of the signals received by the receiver.

The controller may control the attenuator as an analog signal or a digital signal. In the case of performing control with a digital signal, the attenuation is preferably determined by the value of a control word.

The control may be based on the power level of the signals transmitted by the communication system transmitter and / or based on the power level of the signals received by the receiver and / or based on the power level of the signals received by the additional communication system receiver of the apparatus. To determine the desired attenuation. The power level of the signals received by the receiver and the power level of the signals received by the communication system receiver of the apparatus may include an indication of the power level at which the signals are transmitted by the communication system transmitter, and thus the signal And an indicator for the amplification factor currently employed by the communication system transmitter for transmitting the signals. Therefore, the power level of the signals transmitted by the communication system transmitter exceeds a certain value and / or the power level of the signals received by the receiver exceeds a certain value and / or the power of the signals received by the communication system receiver. If the level is below a certain value, a high attenuation can be selected. Further, if the power level of the signals transmitted by the communication system transmitter increases and / or the power level of the signals received by the receiver increases and / or the power level of the signals received by the communication system receiver decreases, Attenuation may be increased. The combination of signals may be performed by combining analog signals or digital signal information.

The invention can be employed in any apparatus including a communication system transmitter for transmitting signals in a first frequency band and a receiver for receiving signals in a second frequency band.

For example, the communication system transmitter may be part of a GSM transceiver, part of a WCDMA-GSM transceiver, part of a US-TDMA, or part of a CDMA transceiver, but is not limited thereto. In particular, the present invention has an advantage when used in communication systems utilizing varying power levels.

For example, the receiver may be a satellite positioning system receiver such as a GPS receiver or a Galileo receiver, but may be any type of receiver in the same way.

Other objects and features of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.

1 illustrates modulation of a GPS carrier frequency.

2 is a conceptual block diagram of a mobile telephone in which an embodiment of the present invention is mounted.

2 is a conceptual block diagram of a mobile telephone 1 in which an embodiment of the present invention is mounted. Only the components of the mobile telephone 1 related to the present invention are described.

The mobile phone 1 supports the GPS location tracking function and the mobile communication function through the GSM network.

The mobile phone 1 includes a GPS receiver 10 to support the GPS location tracking function. The GPS receiver 10 includes a band pass filter (BPF) 11, a low noise amplifier (LNA) 12, a variable gain attenuator 13 as an attenuator, and a radio frequency (RF) back end and a digital signal processor interconnected in series. (DSP) processing block 14. Radio frequency (RF) back end and digital signal processor (DSP) processing block 14 includes mixers. The radio frequency (RF) back end and digital signal processor (DSP) processing block 14 optionally includes a controlling access to the variable gain attenuator 13, which is indicated by the first diagonal line. The mobile phone 1 further comprises a GPS antenna 15 connected to the band pass filter BPF 11 of the GPS receiver 10.

Low noise amplifier (LNA) 12, variable gain attenuator 13, and radio frequency (RF) back end and digital signal processor (DSP) processing block 14 are integrated within a single ASIC 16 in the provided embodiment. This ASIC 16 is represented by the dashed line in FIG. 2.

For example, only variable gain attenuator 13 and radio frequency (RF) back end and digital signal processor (DSP) processing block 14 or low noise amplifier (LNA, 12) and radio frequency (RF) back end and digital signal processor Only the (DSP) processing block 14 may be integrated into a single ASIC 16.

In order to support the mobile communication function, the mobile telephone 1 includes a GSM transceiver 20 that includes a GSM transmitter 30 and a GSM receiver 40.

The GSM transmitter 30 includes a transmitter block 31 including a mixer connected in series with each other, a variable power amplifier 32 and an additional amplifier 33. When a super heterodyne transmitter is used, the gain control of the variable power amplifier 32 may be distributed to several intermediate frequencies in the transmitter block 31 including the mixers.

The transmitter block 31 including the mixers, the variable power amplifier 32, and the additional amplifier 33 are integrated into a single ASIC 34 in the embodiment provided by the present invention. This ASIC 34 is shown in dashed lines in FIG. 2. Or, for example, only the transmitter block 31 and the variable power amplifier 32 including mixers may be integrated into a single ASIC 34.

The GSM receiver 40 includes a receiver block 43 comprising a first amplifier 41, a variable power amplifier 42, and mixers connected in series with each other.

Receiver block 43 comprising first amplifier 41, variable power amplifier 42, and mixers is integrated into a single ASIC 44 in an embodiment according to the present invention. Such an ASIC is indicated by a dotted line in FIG. Or, for example, only the receiver block 43 including the variable power amplifier 42 and the mixers may be integrated in a single ASIC.

The mobile phone 1 further comprises a GSM antenna 25 which is connected to the antenna switch 21, which is connected to an additional amplifier 33 and a first amplifier 41.

In addition, the mobile phone 1 comprises an automatic gain control (AGC) element 50, the automatic gain control (AGC) element 50 having control access to the variable gain attenuator 13 of the GPS receiver 10, GSM Control access to the variable power amplifier 32 of the transmitter 30 and control access to the variable power amplifier 42 of the GSM receiver 40. Or, an automatic gain control (AGC) element 50 is also connected to a radio frequency (RF) back end and a digital signal processor (DSP) processing block 14, which is indicated by a second oblique line in FIG.

Note that the input connection of the automatic gain control (AGC) element 50 is not shown. In particular, this input may be received by a transmitter block 31 comprising mixers, may be received at a receiver block 43 comprising mixers, and / or a radio frequency (RF) backend and digital signal processor ( DSP) may be received at the processing block 14.

The radio frequency (RF) received through the GPS antenna 15 is band pass filtered by the band pass filter BPF 11, amplified by the low noise amplifier LNA 12, and the variable gain attenuator 13) and processed in a radio frequency (RF) back end and digital signal processor (DSP) processing block 14 in a conventional manner. Processing operations within the radio frequency (RF) backend and digital signal processor (DSP) processing block 14 may include, for example, down-converting a radio frequency (RF) signal to baseband, the corresponding signal; Determining and tracking a C / A-code in a signal adopted by the GPS satellite transmitting the signal, decoding navigation information present in the tracked signal, and determining a current location of the mobile phone 1. Performing a position operation.

As a concept of mobile communication, a radio frequency (RF) signal received by the GSM receiver 40 through the GSM antenna 25 and having a carrier frequency corresponding to, for example, 1800 MHz, is transmitted from the GSM receiver 40 in a conventional manner. Is processed. The processing operation includes a first amplification step by the first amplifier 41, an amplification step performed by the variable power amplifier 42 with the currently set amplification factor, and down-conversion inside the receiver block 43 including mixers. (down-conversion) step is included.

In the concept of mobile communication, the signal transmitted by the GSM transmitter 30 is processed in the GSM transmitter 30 for transmission in a conventional manner. This processing operation is an up-conversion operation in a transmitter block 31 comprising mixers provided with the corresponding signal, for example an up-conversion operation to a carrier frequency of 1800 MHz, currently set by the variable power amplifier 32. An amplification operation performed with the amplification factor, and an additional amplification operation performed by the additional amplifier 33. The signal output by the additional amplifier 33 is then transmitted by the GSM antenna 25, causing wideband noise in the GPS band corresponding to 1575.42 MHz +/- 5 MHz. The broadband noise overlaps with all satellite signals arriving at the GPS antenna 15, and therefore the GPS antenna 15 receives a composite radio frequency (RF) signal.

The adjustment of the individual attenuation applied to the radio frequency (RF) signals received by the variable gain attenuator 13 of the GPS receiver 10 is described in detail below.

In the first state, the GSM transmitter 30 transmits no signal. In this first state, the automatic gain control (AGC) element 50 does not provide any automatic gain control (AGC) signal to the variable power amplifier 32 or variable gain attenuator 13. In this case, the attenuation applied by the variable gain attenuator 13 is set to a predetermined low value, for example to a value of zero.

In the second state, the GSM transmitter 30 transmits signals via the GSM antenna 25 as described above. The amplification factor adopted by the variable power amplifier 32 of the GSM transmitter 30 is an automatic gain control (AGC) element (AGC) using an automatic gain control (AGC) signal in a known manner in accordance with the current requirements. 50), for example, current channel conditions.

Like other communication systems, DECT is based on the concept that receive and transmit operations occur at the same frequency but in a synchronized manner in a sequence (ie, use different time slots). Such communication systems are called time division duplex (TDD) systems. If the transmit and receive operations use the same frequency, the signal level of the received signals is a good estimate of the required power level of the signals to be transmitted.

Therefore, as in US-TDMA, CDMA and W-CDMA, in GSM the received signal level and the transmitted signal level are related to each other. If the signal level of the received signal is high, a low transmission power level is used. If the signal level of the received signal is low, a high transmission power level is used. The automatic gain control (AGC) element 50 monitors both the received signal level and the transmitted signal level and sets the amplification factors of the variable power amplifier 32 and the variable power amplifier 42 as required.

Therefore, the information about the power level of the received GSM signal level is used in the automatic gain control (AGC) element 50 to also control the satellite positioning system.

When the amplification factor of the variable power amplifier 32 is set to a low value by the automatic gain control (AGC) signal of the automatic gain control (AGC) element 50, the GSM transmitter 30 transmits signals at a low power level. do. The automatic gain control (AGC) element 50 applies the same automatic gain control (AGC) signal to the variable gain attenuator 13 and therefore sets the attenuation of the variable gain attenuator 13 to a low value. Therefore, for all radio frequency (RF) signals received via the GPS antenna 15, low attenuation is applied.

If the power level of the signals transmitted via the GSM antenna 25 is low, the power level of the broadband noise reaching the GPS antenna 15 is also low. Therefore, even if the power level of the satellite signal reaching the GPS antenna 15 is rather high, the resulting signal-to-noise ratio (SNR) of the resulting composite radio frequency (RF) signal is still high enough to be able to perform a reliable evaluation. Since low attenuation is performed on the complex radio frequency (RF) signal received by the variable gain attenuator 13, the radio frequency (RF) provided to the radio frequency (RF) back end and the digital signal processor (DSP) processing block 14. The signal has a high power level sufficient to allow evaluation. Thus, no error due to too much noise is present in the result of the evaluation. On the other hand, if the power level of the satellite signal reaching the GPS antenna 15 is rather low, even low broadband noise causes the signal-to-noise ratio (SNR) of the composite radio frequency (RF) signal to be somewhat low. In this case, even if low attenuation is applied to the complex radio frequency (RF) signal received by the variable gain attenuator 13, it prevents the evaluation in the radio frequency (RF) back end and the digital signal processor (DSP) processing block 14. An error due to too much noise and therefore too much noise is present in the evaluation result.

When the amplification factor is set to a high value by the automatic gain control (AGC) signal of the automatic gain control (AGC) element 50, the GSM transmitter 30 transmits signals at a high power level. The automatic gain control (AGC) element 50 applies the same automatic gain control (AGC) signal to the variable gain attenuator 13 and therefore sets the attenuation of the variable gain attenuator 13 to a high value. Therefore, high attenuation is applied to all radio frequency (RF) signals received via the GPS antenna 15.

If the power level of the signals transmitted via the GSM antenna 25 is high, the power level of the broadband noise reaching the GPS antenna 15 is also high. Therefore, even if the power level of the satellite signal reaching the GPS antenna 15 is rather high, the resulting signal-to-noise ratio (SNR) of the resulting composite radio frequency (RF) signal is too low to perform a reliable evaluation. Since high attenuation is performed on the complex radio frequency (RF) signal received by the variable gain attenuator 13, the radio frequency (RF) backend and the radio frequency (RF) delivered to the digital signal processor (DSP) processing block 14 ) Signal has a power level that is too low to enable evaluation. Thus, no error due to too much noise is present in the result of the evaluation.

Since the same automatic gain control (AGC) signal is applied to the variable gain attenuator 13 and the variable power amplifier 32, as the amplification gain increases, it attenuates and increases, so that the GSM transmitter 30 always transmits to the GSM transmitter 30. Thereby to optimize and adapt to the wideband noise of the transmitted signals and the current combination of arriving satellite signals.

It should be noted that the variable gain attenuator 13 may be controlled in a conventional manner within the low range of possible gain values. For example, it may be controlled depending on the strength of the currently received radio frequency (RF) signal. Further control may be performed by a signal transmitted via a first indicated optional connection from the radio frequency (RF) back end of the GPS receiver 10 and the DSP in the digital signal processor (DSP) processing block 14. This may increase or decrease the attenuation in a manner independent of the setting of the automatic gain control (AGC) element 50. Alternatively, the signals from the automatic gain control (AGC) element 50 and the radio frequency (RF) back end and digital signal processor (DSP) processing block 14 may be combined in a suitable manner to obtain appropriate attenuation. This combination of information for the attenuation values may include the radio frequency (RF) backend and digital signal processor (DSP) from the automatic gain control (AGC) element 50 via a select connection in which automatic gain control (AGC) information is second indicated. If passed to processing block 14, it may be performed at a radio frequency (RF) back end and a digital signal processor (DSP) processing block 14. The information reached may be digital word or analog signal values. Alternatively, the automatic gain control (AGC) element 50 may also be responsible for further control. In the latter case, the automatic gain control (AGC) signal provided by the automatic gain control (AGC) element 50 to the variable power amplifier 32 of the GSM transmitter 30 is a variable gain attenuator of the GPS receiver 10. Prior to the provision of 13), adjustments are made to the requirements of additional control.

Furthermore, the attenuation applied to the satellite signals received by the present invention is not necessarily applied by the variable gain attenuator 13 or necessarily by the variable gain attenuator 13.

In another embodiment, the attenuator may be mounted after the mixers in the radio frequency (RF) back end and digital signal processor (DSP) processing block 14.

Attenuation may be spread over several blocks, for example variable gain attenuator 13 and / or low noise amplifier (LNA) 12 and / or intermediate frequency amplifiers and / or radio frequency (RF) backend and digital signal. The baseband amplifiers in the processor (DSP) processing block 14 may be distributed.

If a super heterodyne structure is used for the GPS receiver 10, the radio frequency (RF) back end and digital signal processor (DSP) processing block 14 may include several mixers and intermediate frequency filters, with variable gain. The gain control function that controls the gain of the attenuator 13 and / or the gain of the attenuator in the radio frequency (RF) back end and digital signal processor (DSP) processing block 14 may be distributed over several frequencies.

It should be noted that the above-described embodiments constitute only one of many possible embodiments of the present invention.

The invention is applicable to an apparatus comprising a communication system transmitter for transmitting signals over an air interface in a first frequency band and a receiver for receiving signals at an air interface in a second frequency band.

The invention may also be applied to improve the performance of a receiver coupled to a single device including a communication system transmitter.

Claims (35)

A communication system transmitter for transmitting a signal over a radio interface in a first frequency band; A receiver for receiving signals via an air interface in a second frequency band, the receiver comprising an attenuation element for attenuating the signals received by the receiver and The attenuation applied to signals received by the receiver by the attenuator to a higher value when the communication system transmitter transmits signals at a power level exceeding a specified value, the communication system A control unit for setting attenuation applied to signals received by the receiver by the attenuator to a lower value when the transmitter does not transmit a signal, wherein the higher value is: And when the attenuation is set to the higher value, the apparatus is to be high enough to prevent evaluation of the attenuated received signals. The method of claim 1, The communication system transmitter includes a variable amplifier for amplifying signals to be transmitted by the communication system transmitter, and the control unit includes: The attenuation applied to the signals received by the receiver by the attenuator increases as the amplification factor of amplification to be applied to the signals to be transmitted by the variable amplifier by the communication system transmitter increases. Apparatus for improving the performance of a receiver, characterized in that the setting to a value. The apparatus of claim 1 or 2, wherein the apparatus comprises: A communication system section comprising said communication system transmitter and A receiver section comprising said receiver for receiving signals in a second frequency band, And the control unit is located in at least one of the communication system section and the receiver section. The method of claim 3, wherein the control unit, At least a portion of a processor provided within the communication system section and And at least a portion of a processor provided within the receiver section. The method according to claim 1 or 2, The receiver for receiving signals in the second frequency band further includes an automatic gain control element, wherein the control unit includes: Combining information from the automatic gain control element with information from a communication system section including the communication system transmitter to determine attenuation to be established. The method of claim 1 or 2, wherein the control unit, Determine attenuation to be set based on at least one of a power level of signals transmitted by the communication system transmitter and a power level of signals received by the receiver receiving signals in the second frequency band. Device to improve performance. The apparatus of claim 1 or 2, wherein the apparatus comprises: And a communication system receiver for receiving signals in the first frequency band, wherein the control unit comprises: And determine the attenuation to be set based on the power level of the signals received by the communication system receiver. The method of claim 7, wherein the control unit, And determine attenuation to be set further based on power levels of signals received by the receiver receiving a signal in the second frequency band. The method according to claim 1 or 2, The attenuator includes a variable gain attenuator, the variable gain attenuator, Modifying the attenuation applied to the received signal by the variable gain attenuator, thereby applying at least a portion of the set attenuation to the signal received by the receiver. The receiver of claim 9, wherein the receiver for receiving signals in the second frequency band comprises: An amplifier for amplifying signals received through the antenna of the device and Further comprising a processing unit for processing the signals amplified by the amplifier, And the variable gain attenuator is implemented between the amplifier and the processing unit. The method according to claim 1 or 2, And said attenuator is integrated in an integrated circuit with at least one other element of said receiver for receiving signals in said second frequency band. The method according to claim 1 or 2, The attenuator is implemented in a dedicated integrated circuit, And said dedicated integrated circuit is located outside of other elements of said receiver for receiving signals in said second frequency band. The method according to claim 1 or 2, The attenuator includes a variable amplifier, the variable amplifier, Applying at least a part of the set attenuation to the signal received by the receiver by changing the amplification factor of the amplification applied to the received signal by the variable amplifier. The method according to claim 1 or 2, And an antenna coupled to the receiver for receiving signals in the second frequency band, wherein the attenuator comprises: And detuning the antenna to apply at least a portion of the set attenuation to a signal received by the receiver. The attenuator of claim 1 or 2, For at least one element of the receiver comprising reducing the supplied operating voltage, thereby applying at least part of the set attenuation to a signal received by the receiver receiving signals in the second frequency band. A device for improving the performance of a receiver. The receiver of claim 1 or 2, wherein the receiver for receiving signals in the second frequency band comprises: A first conversion element for converting the received radio frequency signal into an intermediate frequency signal and A second conversion element for converting the intermediate frequency signal output from the first conversion element into a baseband signal, The attenuator, And apply the set attenuation to a signal received by the receiver at at least one of a radio frequency, an intermediate frequency, and a baseband frequency. The method according to claim 1 or 2, And means for evaluating said attenuated received signals only if said attenuated received signals have a sufficiently high power level. An apparatus comprising a communication system transmitter for transmitting a signal over a radio interface in a first frequency band and a receiver for receiving signals over the air interface in a second frequency band, the apparatus comprising: The receiver comprises an attenuation element for attenuating signals received by the receiver, When the communication system transmitter transmits signals at a power level exceeding a specified value, the attenuation applied to the signals received by the receiver by the attenuator is set to a higher value, and the communication system transmitter And a control unit for setting the attenuation applied to the signals received by the receiver by the attenuator to a lower value when the signal does not transmit, The higher value is a value high enough to prevent evaluation of the attenuated received signals when the attenuation is set to the higher value. As a method for improving the performance of a receiver, The receiver is combined into a single device with a communication system transmitter for transmitting signals over the air interface in a first frequency band, the receiver receiving signals over the air interface in a second frequency band, Attenuating the signal received by the receiver with a higher attenuation when the communication system transmitter transmits signals at a power level exceeding a specified value, and If there is no signal transmitted by the communication system transmitter, attenuating the signal received by the receiver with lower attenuation, The higher value is a value high enough to prevent evaluation of the attenuated received signals when the attenuation is set to the higher value. The method of claim 19, The communication system transmitter amplifies signals to be transmitted with a variable amplification factor, The signals received by the receiver for receiving signals in the second frequency band are attenuated by attenuation that increases as the amplification factor used by the communication system transmitter for amplifying the signals to transmit increases. How to improve performance. The method according to claim 19 or 20, in order to determine the attenuation to be used, Information provided by an automatic gain control for the receiver and information provided by a communication system section including the communication system transmitter are combined. The attenuation to be used according to claim 19 or 20, Improve the performance of a receiver based on at least one of a power level of signals transmitted by the communication system transmitter and a power level of signals received by the receiver receiving signals in the second frequency band. How to make it. The attenuation to be used according to claim 19 or 20, And is determined based on the power level of the signals received in the first frequency band by the communication system receiver of the device. The attenuation to be used according to claim 23, wherein And further determined based on power levels of signals received by the receiver receiving a signal in the second frequency band. The method of claim 19 or 20, And the signals received by the receiver for receiving signals in the second frequency band are attenuated by attenuation applied by a variable gain attenuator. The method of claim 19 or 20, Signals received by the receiver for receiving signals in the second frequency band, Attenuated by reducing amplification applied to signals received by the receiver. The method of claim 19 or 20, Signals received by the receiver for receiving signals in the second frequency band, And attenuated by detuning the antenna for transmitting signals to the receiver. The method of claim 19 or 20, The signals received by the receiver for receiving signals in the second frequency band are Attenuating by reducing the operating voltage supplied for at least one element of the receiver. The method of claim 19 or 20, Signals received by the receiver for receiving signals in the second frequency band, Attenuating at least one of radio frequency, intermediate frequency, and baseband frequency. The method of claim 19 or 20, Evaluating the attenuated received signals only if the attenuated received signals have a sufficiently high power level. The method of claim 18, The communication system transmitter includes a variable amplifier for amplifying signals to be transmitted by the communication system transmitter, and the control unit includes: The attenuation applied to the signals received by the receiver by the attenuator increases as the amplification factor of amplification to be applied to the signals to be transmitted by the variable amplifier by the communication system transmitter increases. Device set to a value. 32. The method of claim 18 or 31, The receiver for receiving signals in the second frequency band further includes an automatic gain control element, wherein the control unit includes: Combining information from the automatic gain control element with information from a communication system section including the communication system transmitter to determine attenuation to be established. The method of claim 18 or 31, wherein the control unit, Determine an attenuation to be set based on at least one of a power level of signals transmitted by the communication system transmitter and a power level of signals received by the receiver receiving signals in the second frequency band. . 32. The apparatus of claim 18 or 31, wherein the device is And a communication system receiver for receiving signals in the first frequency band, wherein the control unit comprises: And determine the attenuation to be set based on the power level of the signals received by the communication system receiver. 32. The method of claim 18 or 31, And means for evaluating said attenuated received signals only if said attenuated received signals have a sufficiently high power level.

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