MXPA97006076A - Autoverification transceiver - Google Patents

Abstract

The present invention relates to an integrated radiofrequency transceiver comprising an adversity of receivers and transmitters capable of performing a self-verification operation to determine whether the reception and transmission paths operate properly. The diversity receiver includes two receiver paths, a first path to receive radio communications having a permitted bandpass, and a second receiver path to receive radio signals from other radio port channels in use to help build its own proximity list

Description

AUTOVERIFICATION TRANSCEIVER FIELD OF THE INVENTION The present invention relates generally to the field of radio frequency transceivers and more particularly to a radio frequency transducer incorporating self-verification capabilities.

BACKGROUND OF THE INVENTION An application for the use of radio frequency (RF) transceivers is to transmit and receive RF signals for radio stations used in wireless communication systems. Currently, those radiofrequency transceivers adapted for radio ports used within a wireless communication system are not integrated units with respect to the operation of certain important functions. For example, vital functions, such as self-verification of the transceiver, are effected by several other external physical components. In addition, these other external components can be used to measure those radio channels in use by other nearby radio ports to assist in the construction of REF lists: 24706 near a radio port. This dependence on the external components used in connection with the current transceivers leads to higher design costs due to the increased complexity of an interface between the transceiver and the external components and the inclusion of the external components themselves. Such a design can also increase the chances of failure of the radio port leading to higher maintenance costs. Accordingly, there is a need for a fully integrated transceiver unit that performs the vital functions of the transceiver such as self-verification and measurement of the active radio channels of other radio transceivers internally without relying on external components.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, there is described an integrated radio frequency transceiver comprising a diversity receiver and transmitter capable of performing a self-verification operation to determine whether the trajectories of the receiver and the transmitter are operating properly. The diversity receiver includes two receiver paths, a first path to receive radio communications having a permitted bandpass, and a second receiver path to receive radio signals from other radio frequency transceivers. The transmitter includes a quadrature modulator adapted to receive signals from the local oscillator of a frequency synthesizer and an intermediate frequency synthesizer to generate appropriate transmission frequencies. The transmission path of the transmitter is duplexed via the bandpass filter with the second receiving path. A frequency synthesizer also provides a local oscillator signal for a mixing process in the first receiver path. The first receiver path, which includes two parallel bandpass paths for receiving two frequency ranges, also receives a local oscillator signal from the frequency synthesizer to mix it with an incoming signal. For self-verification purposes, the transmitter is adapted to transmit a test signal which is routed by an internal switch to each of the receiver paths. An exact reception of the test signal indicates that the trajectories of the transmitter and the receiver operate properly. The second alternative receiver path allows the radio frequency transceiver to detect radio signals from other radio frequency transceivers in the wireless communication system to maintain a list of active radio frequency transceivers.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present invention can be obtained from the consideration of the following overall description of the drawings in which: Figure 1 is a schematic block diagram showing an exemplary embodiment of a smart radio port in accordance to personal invention; and Figure 2 is a schematic block diagram of an exemplary embodiment of an integrated transceiver module according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figure 1 therein is shown a schematic block diagram of a module 10 of Intelligent Radio Port Unit (IRP) 10 according to the present invention. As shown, the IRP unit includes a transceiver module 12 which is coupled to a digital control module 14. As would be understood by one skilled in the art, in the embodiment shown the transceiver module 12 is a single board transceiver which is part of the Intelligent Radio Port Unit (IRP) 10. The main function of the transceiver module 10 is to transmit and receive digitally modulated radio frequency (RF) control signals and information signals to and from mobile wireless communication devices. As will be explained, the transceiver has an integrated test or verification circuit to verify itself in response to the signals generated from the digital control module 14. In addition, the transceiver 12 is capable of detecting the radio frequency interference signatures of other ports Smart radio (IRP) that is, sniff, to therefore build a close list of those nearby radio ports. Referring to Figure 2, transceiver 12 is shown as an RF circuit module starting from an intelligent radio port of a wireless communication system. In a preferred embodiment, the transceiver transmits at 869 to 894 MHz and may receive either in the 824 to 849 MHz band or in the 869 to 894 MHz band, however as may be understood by one skilled in the art, other bands can also be used. The operating capabilities of the transceiver allow the device to operate in the following functional modes: transmitter, diversity receiver, synthesizer, self-test and sniffing modes, modes each of which will be discussed in more detail here. As discussed herein, the present disclosure deals only with the aspect of the processing of the radiofrequency signal of the invention, such as that performed by the transceiver 12. The digital control portion of the transceiver is provided by the digital control module (shown in FIG. Figure 1), which is adapted to the interface with the transceiver module 12, as could be understood by a person skilled in the art. All signals except the two RF signals are interconnected directly to the board of the digital control module. Referring still to Figure 2, the transmitting portion of the transceiver of the present invention includes a quadrature modulator 20 which operates for example at 5.0 volts and produces a power output of approximately -3 dBm (decibels below 1 milliwatt). Quadrature modulation, ie the modulation of two carrier components separated 90 degrees in phase by separate modulation functions, is well known to those skilled in the art. In the context of the present invention, such modulation signals are known as IrN and QIN signals for transmission operations and I0?; T / Hout and Qout / Qlout signals for reception operations. The quadrature modulator 20 of the present invention includes an integrated energy controller wherein the energy produced can be attenuated by approximately 50 dB. An input compatible with the complementary transistor transistor / metal oxide semiconductor (CMOS / TTL) semiconductor allows the device to move to the low power mode when less than 10 microswitches of the power supply are consumed. The quadrature modulator of the present invention can be found, for example, in a single-chip integrated circuit package model No. W2011 of AT &T Corp. In the embodiment shown in Figure 2, the quadrature modulator 20 is a direct conversion modulator with an integrated displacement mixer which prevents an external voltage controlled oscillator (vVCO) from being carried downwards by a large transmission signal. The transmitter requires local oscillator signals (LO) low level to eliminate the use of an amplifier on synthesizers. The transmitter receives a LO signal at 82.2 MHz, via a 3-way splitter 22, from an intermediate frequency (IF) 24 synthesizer. The transmitter also receives another LO signal at 745-770 MHz or 787-811 MHz from a digital synthesizer. agile frequency 26, 28 based on the transmission frequency, thus allowing outputs in the upper sideband to produce the desired frequency. As can be seen, the LO signals of the agile synthesizer 26, 28 arrive via the resistive dividers 30, 32, a fixed attenuator 34, and the SPDT switch 36 and a low pass filter 38. The use of frequency synthesizers, which provide Multiple frequency outputs are well known to those skilled in the art. As can be understood, the agile frequency synthesizers 26, 28 used here, can be programmed and controlled by a processor, for example, a microprocessor (not shown), to obtain the desired signals. In a preferred embodiment of the present invention, the output of the quadrature modulator 20 is the input to the first stage of an amplifier 40 which increases the output signal by a given amount, for example 18 dB. The output of this amplifier 40 enters a final power amplifier stage which adds another 7dB of gain to this signal. The output of the amplifier 40 then enters a directional coupler of -15dB 42 to verify the power output to the antenna 44. Saying that after traveling through a bandpass filter (BPF) duplexer 46 and the SPDT switch 48, the processed power signal Ir? j / Q; N is directed out of the antenna 44 to be radiated. The SPDT switch 48 directs the RF energy to the antenna 44 or other receiver paths for series connection tests as will be described. The smart radio ports used with the integrated transceiver of the present invention 12 require that the transmit power be reduced in steps of 4 dB of the maximum nominal transmit power that the transceiver can transmit. To achieve a flat characteristic independent of the scattered gain in the amplifier stages, a leveling circuit is used, including the power detector 50, external to the amplifier 40. The output of the transmitter is adjusted by changing the control voltage to a control input gain of the transmitter. A pulse width modulation (PWM) signal from a microcontroller within the power detector, the low pass is filtered to produce such a CD control signal. The transmitter can then be calibrated using an external power meter to find a corresponding PWM number for each power level. A problem, however, is that with small variations in the gain or load impedance, the power output can also fluctuate. Also if antenna 44 is accidentally removed with the unit in operation, inverted power can damage the unit. To solve this problem, the power feedback circuit fed into the directional coupler of -15 dB 42 is adapted to detect the inverted power and rectify it. This signal is, in effect, added to the output of the CD control signal of the microcontroller. Accordingly, the circuit will establish that such output of the detector diode in the directional coupler 42 will be equal to the reference level. The reference level is then derived directly from the microcontroller and is set according to the required output power. As might be understood, care must be taken to recognize that for the purposes of self-verification the transmitter transmits at 824-896 MHz, but the input to the bandpass filter (BPF) 46 duplexer accepts frequencies of only 869-894 MHz, which causes a signal loss that could be as high as 60 dB. Therefore, for each calibration of the trancepting unit, the exact signal that arrives at the receiver must be found. As well, the channel used to make the self-verification should preferably be the channel not used by the mobile wireless communication devices. With respect to the diversity reception function of the tranceptor 12, it should be understood that the receiver is to receive digitally modulated RF control and information signals from mobile wireless communication devices and release baseband signals to a uni ", d processor. baseband The receiver handles the signals from -15dBm to -102dBm or 87 dBm of the dynamic range.

The receiver employs a double heterodyne method in which each of the channels receives, i.e. two mixing processes, one in the mixer 51, 52 and another in the IF subsystems of the receiver 53, 54, respectively. Two intermediate frequencies are used, one at 82.2 MHz for the agile frequency synthesizers 26, 28 and the IF 24 synthesizer, and the other at 455 kHz. The intermediate frequencies of the agile frequency synthesizers follow the path through the resistive dividers 30, 32 to the switch 21, to the amplifier 23, to the divider 25 to the amplifiers 27, 29 of either the mixer 51 or the mixer 52, respectively. The local oscillator source for the 455 kHz frequency is derived from a crystal oscillator 56 at 1.82 MHz, which is the frequency divided by four in the frequency divider 58 before entering the IF subsystems of the receiver. The diversity receiver consists of two identical receivers, a first RXO receiver and a second RX1 receiver. Both RXO and RX1 include RF amplification circuits. downward conversion, IF bandpass filtering, IF amplification, gain control, demodulation and baseband. As can be seen, both RXO and RX1 receptors include similar components. The path of the RXO, specifically, includes the ante 50, BPF or LNA 63 to the BPF 65 or BPF 62 to LNA 64 to the BPF 66, the switch SPDT 68, MIXER 52, Filter IF 7'6 to the Subsystem of IF of the Receiver 53 in conjunction with the IF filter? 3, to provide signals I, -ut and Qout. The trajectory of the PX1, specifically, includes the antenna 44, SPDF switch 43, BPF 46 duplexer, LNA 74, BPF 76, Mixer 52, IF filter 78 to the IF Subsystem of the Receiver 54 in conjunction with the IF filter 79, for provide the signals Il t and QIOUT- With respect to the RXO receiver, the RF amplification circuit includes a 4-way switch 80, which can connect the received signal to the bandpass filter of the reception path (BPF), it is say 869-894 (MHz) or 824-849 (MHz), respectively. The switch 80 can also send a self-test signal from the transmitter to the bandpass filter of 869-894 MHz 61. Those signals, amplified by the low noise amplifier (LNA) 64 which has a typical characteristic noise of about 3dB, and the LNA 63 which has a characteristic noise of approximately 2.5 dB, are sent to the mixer 51 by the SPDT switch 68. The LNA 64 has a ldB compression point of 21 dBm to direct the level band signals B high without saturating the amplifier, as could be understood by one skilled in the art.

The downstream converter circuit of the RXO receiver includes a dually balanced mixer 51, which cancels the incoming received signals from the RF amplifier circuit with an agile LO frequency to produce the first IF at 82.2 MHz. A second mixer in the IF 53 subsystem combines the first IF at 82.2 MHz with a LO frequency of 82.2 MHz from the IF synthesizer 24 to produce a third IF at 455 kHz. Finally, this 455 kHz signal is mixed with a fixed 455 kHz LO to produce the Iout and Qout signals. The IF bandpass filter 70 of the RXO receiver provides the channel separation function for the receiver. In the mode shown, the 3 dB bandwidth of the filter is 30 kHz. As would be understood by one skilled in the art, the filter 70 passes the tuned channel and rejects all other channels. A first IF filter 70 is a surface acoustic wave filter of 82.2 MHz and requires equalizing the input / output at 50 ohms. The other IF 73 bandpass filter is at 455 kHz with a 3 dB bandwidth of 28 kHz and 20 kHz respectively. This filter 73 is preferably a ceramic filter with no low group delay response, the nominal impedance being 1000 ohms to 1500 ohms. The receiver IF subsystem 53 is a power IF system for operation at IF frequencies as high as 500 MHz and the second IF frequencies as high as 22 MHz. Subsystem 53, preferably includes the mixer, IF amplifiers, I and Q demodulators, a closed-phase quadrature oscillator, an automatic gain control (AGC) detector, and a deflection system with external downward power, wherein in a Preferred subsystem is a single AS607 IC microcircuit from Analog Devices, Inc. The IF subsystem includes a low noise high intercept input mixer that is of the double balanced Gilbert Cell type and operates linearly for RF inputs that encompass -102 to -15 dBm. The mixing section also includes a local oscillator preapple, which decreases the operation to -16 dBm. The one-sided IF output can directly drive a bandpass filter with an impedance of 200 ohm or greater. A gain control input can serve as either a manual gain input or an output signal indicating the strength of the radio signal based on the automatic gain control voltage (RSSI). The path of the diversity receiver RX1 is similar to the reception path of the RXO, except for the two-way switch SPDT 48 which can initiate the signal transmitted to the antenna 44 or to the path of the RXO receiver for a self-verification. The BPF-based duplexer 46 provides isolation between the transmission and reception paths. As shown in Fio ra 1, the sintetizadcr functional group of the transceiver of the present invention 12 consists of a single IF 24 synthesizer that provides an LO source of 82.2 MHz, a fixed 1.82 MHz crystal oscillator 56 which is divided by four to produce the 455 kHz signal and two agile synthesizers of frequency 26 and 28. The three synthesizers 24, 26 and 28 are programmed and controlled by a microprocessor (not shown), so that the outputs of the synthesizers of frequencies are coherently linked at a reference frequency of 15 MHz. The microcircuit used for the closed phase circuit (PLL) operation is preferably an LMX 2332 from National Semiconductor Corp., which has dual synthesizers that include prescalers. Each microcircuit is used. to generate an RF signal and a local IF oscillator. Since the tranceptor has to transmit to two different bands and receive two different bands. The number of PLLs required will be at least four if a direct superconversion transmitter is used. In the embodiment shown, a relay transmitter was used so that only two RF LOs were required. As discussed, the transceiver 12 of the present invention can operate in a self-verification mode, in which the receiver essentially self-verifies with the command of a central processing unit on the digital control module to find any components with faults in the transmission or reception trajectory. The transmitter transmits a verification signal, for example a specially encoded message, of 824-849 MHz which is sent by the SPDT switch 84 to both RXO and RX1 receivers. A detection by the processing unit of a successful reception of the verification signal in a separate port of digital control module for each receiver indicates that the transmission and reception paths operate properly in the transceiver 10. Although the filter of the duplexer 46 in the transmission output is 869-894 MHz, the filter will still pass the test signal with approximately 60 dB of attenuation, sufficient for verification purposes. Another unique feature of the present invention is that the transmission signal is heterodynically generated to receive the local oscillator with the IF signal of 82.2 MHz, which in turn eliminates the use of two synthesizers. The transceiver of the present invention may also operate in a sniff mode to detect radio interference signatures and other radio-intelligent ports (IRP). The SPDT switch 48 operates to send or route RF transmissions received from other IRPs to the alternate reception path RXI. Based on this signal received in the control module, each IRP keeps a list of active IRPs in the surroundings that are stored in the memory in the control module. Since the signals of the other IRPs are not very large a low noise amplifier 74 used in this path may have a low compression point of 1 dB, therefore, an appropriate low noise amplifier was used. From the foregoing, it should be understood that the embodiments described, with respect to the drawings, are merely exemplary and that one skilled in the art could make variations and modifications to the embodiments shown without departing from the spirit and scope of the invention. It is intended that all such variations and modifications be included within the scope of the invention as defined in the appended claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (20)

1. An integrated radiofrequency tranceptor apparatus adapted for use with a radio port used to communicate with a wireless communication system, characterized in that it comprises: an operable transmitter for transmitting radio frequencies within a given frequency band; and a diversity receiver having first and second receiver paths to receive radio frequencies within a given frequency band, the transmitter operates to transmit a self-verification signal to receive on at least one of the first and second receiver paths in response to the self-verification command, wherein a receiver of the self-verification signal of at least one receiver path verifies the proper operation of the transmitter and at least one path of the receiver.

2. The apparatus according to claim 1, characterized in that it also includes a digital control module coupled to the transmitter and the receiver, the digital control module operates to generate the self-verification command and to receive the self-verification signal.

3. The apparatus according to claim 1, characterized in that at least two receiver paths include a first receiver path to receive communication signals intended to be for the radio port and a second receiver path to receive communication signals transmitted from the tranceptores of other radio ports, so that a close list of the other radio ports can be maintained based on the reception of communication signals from other radio ports.

4. The apparatus according to claim 3, characterized in that the transmitter and the second path of the receiver are coupled to a bandpass filter duplexer and combination switch, wherein the duplexer and the combination of the switch allow the communication signals are transmitted and received on a single transmission / reception channel.

5. The apparatus according to claim 1, characterized in that the diversity receiver further includes: a frequency synthesizer; and a heterodyne mixer coupled to the frequency synthesizer, wherein the frequency synthesizer operates to supply a local oscillator signal to the heterodinc mixer to generate the radio frequencies in the diversity receiver.

6. The apparatus according to claim 5, characterized in that the transmitter further includes a quadrature modulator, and wherein the frequency synthesizer further operates to supply a local oscillator signal to the quadrature modulator to generate radio frequencies in the transmitter. .

7. The apparatus according to claim 6, characterized in that the transmitter further includes an intermediate frequency synthesizer which operates to supply a local oscillator signal to the quadrature modulator to generate the radio frequencies in the transmitter.

8. The apparatus according to claim 7, characterized in that the diversity receiver further includes an intermediate frequency receiver subsystem, the intermediate frequency synthesizer further operates to supply a local oscillator signal to the intermediate frequency receiver subsystem in the diversity receiver.

9. The apparatus according to claim 1, characterized in that the transmitter further includes a quadrature modulator to modulate the communication signals generated by the tranceptor, the transmitter further includes a directional coupler and power detector coupled to the quadrature modulator to provide a circuit power leveler for the signals transmitted from the tranceptor, the power leveling circuit operates to produce a characteristic flat transmission for the transmitted signals regardless of the fuzzy gain of the associated amplifier stages.

10. The apparatus according to claim 9, characterized in that the power detector produces a pulse width modulation (PWM) control signal to be input to a gain control input of the transmitter, whereby the gain control input adjusts the output of the transmitter in response to the control signal.

11. The apparatus according to claim 9, characterized in that the directional coupler is coupled to detect the inverted power signal input thereof and rectifies the inverted power input signal, wherein the rectified inverted power input signal is added to the PWM control signal.

12. The apparatus according to claim 1, characterized in that the first receiver path includes a first and second sub-paths, wherein the first sub-path includes one or more bandpass filters for receiving radio frequency signals in a first predetermined passband and the second sub-path includes one or more bandpass filters for receiving radio frequency signals in a second predetermined passband.

13. The apparatus according to claim 12, characterized in that the first passband is in the range of 824-849 MHz and the second passband is in the range of 869-984 MHz.

14. The apparatus according to claim 1, characterized in that it further includes an intermediate frequency receiver subsystem in the diversity receiver to provide a second heterodyne mixing process of the second stage for generating radio frequency within the given frequency band.

15. The apparatus according to claim 14, characterized in that the intermediate frequency receiving subsystem is used in at least two diversity receiver receiver paths, a first path to receive radio communications directed to the radio port and an alternative receiver path to detect radio signals transmitted by other radiofrequency transceivers.

16. The apparatus according to claim 2, characterized in that the self-verification signal for the first and second receiver paths is received in a corresponding port separated from the digital control module.

17. An integrated radiofrequency tranceptor apparatus adapted for use with a radio port used to communicate within a wireless communication system, characterized in that it comprises: a transmitter that operates to transmit radio frequencies within a given frequency band; and a diversity receiver for receiving raaio frequencies within a given frequency band, the transmitter operates to transmit a self-paging signal to receive a first receiving path in response to a self-verification command, wherein the reception of the Verification signal verifies the captured operation of the transmitter and the receiving path.

18. The apparatus according to claim 17, characterized in that it also includes a digital control module coupled to the transmitter and the receiver, the digital control module operates to generate the self-verification command and to receive the self-verification signal.

19. The apparatus according to claim 17, characterized in that the diversity receiver includes a second receiving path, wherein the first receiving path is for receiving the communication signals intended to be for the radio port and the second receiving path is for receive the communication signals transmitted from the transceivers of other radio ports, so that a proximity list of the other radio ports can be maintained er. based on the reception of the communication signals for the other radio ports.

20. The apparatus according to claim 18, characterized in that the self-verification signal can be generated for the second receiving path, wherein the verification signal for each receiving path is received in a separate port of the digital control module.