摘要:
A wireless telecommunication apparatus comprising—a baseband for the purpose of generating and receiving base-band signals; —a RF transceiver for the purpose of transmitting and receiving a RF signals, —at least one centralized clock derived from at least one central oscillator; —at least one individual element located within said apparatus and having a EMI coupling with said RF transceiver, and which clocking is likely to generate spurs being modulated with the Tx carrier of said RF transceiver; Characterized in that it further includes: —a least one controllable clocking system for said at least one individual element; —a general control unit (UCM) for the purpose of performing a contextual analysis of the current mode of operation of said wireless telecommunications and, in response to said contextual analysis, for determining a clocking frequency which results in modulated Tx clock spurs out of the receive bands.
摘要:
Process for controlling the switching of the data rate at a digital interface exchanging data and control messages between a Radio Frequency (RF) circuit and a digital circuit, comprising the steps of: setting by default the data rate to a low speed (LS) rate having a density presenting a first lobe being inferior to the frequency band considered in said RF circuit so as to prevent desensitization of the LNAs by the noise produced by said digital interface; storing the data and control messages message into a FIFO and monitoring the level of said FIFO; whenever the level of said FIFO reaches a predetermined threshold value, then controlling said interface to switch to a second high speed (HS) rate in order to flush said FIFO. In one embodiment, the LS frequency is set to a value of 832 MHz, thus preventing simultaneously desensitization of the GSM band and also the GPS band.
摘要:
A signal processing unit is described relates to a communication system by radio waves with frequency modulation comprising a signal processing unit, a transmission stage for transmitting a transmission signal in response to a modulated control signal and in response to a first frequency reference signal, a modulator connected between the processing unit and the transmission stage for forming the modulated control signal in response to an output signal of the processing device and in response to a second frequency reference signal and means for providing the first frequency signal to the transmission stage and for providing the second frequency reference signal to the modulator wherein the first and second frequency reference signal are derived from a signal oscillator.
摘要:
A monolithic RF amplifier circuit (10) suitable for use in the 0.8-2 GHz frequency range comprises, on-chip (12'), a gateable oscillator (24) running at about 2-5 times the amplifier input frequency or higher, coupled to a rectifier (30) and a low pass filter (34) for producing a DC signal which is fed via a bias/gain control circuit (46) to a bias/gain inputs (56, 58) of one or more amplification stages (60, 62) (e.g. GaAs FET) to provide bias therefore to ensure safe operation, and a priority control circuit (42) responsive to the bias. The priority control circuit (42) operates a power switch (18) that couples the amplification stages (60,62) to a power supply, only when bias is present on their bias/gain inputs (56,58) This protects the amplification stages (60,62) against overcurrent operation. A separate external port (68) to the bias/gain control circuit (46) adjusts the magnitude of the bias to permit amplifier gain and power output to be adjusted. By gating the oscillator ON and OFF, high speed burst mode operation of the amplifier is achieved.
摘要:
A radio transceiver including—an antenna (201) switch having a control lead (226); —a RF and front end circuit (202) coupled to said antenna switch and operating in at least one 2G mode and at least one 3G mode; —a RF transceiver (209) coupled to said RF front end and operating in at least a first 2G and a second 3G mode; —a baseband (210) communicating with a set of peripherals and external devices; The radio transceiver is characterized by the fact that it includes: —control means (221) for controlling said antenna switch (201) in a isolated mode; —an programmable adaptive filter controlled by said control means for the purpose of introducing at least one notch for eliminating one corresponding spur. The radio transceiver preferably includes means (215) for performing, under control of said control means (221) a FFT computation for the purpose of elaborating a representation, in the time domain, of the different spurs and/or jammers spoiling the received signal when in isolated mode.
摘要:
The present invention relates to a receiver for processing a received signal (SEQ), said receiver being multimode. The invention is characterized in that it comprises; a) a single RF chip for processing the received signal (SEQ) in any mode, said chip comprising a spreading section (SPREAD SEC) for spreading and downconverting to baseband a received signal (SEQ), and a channel filtering section (CH SEC) for DC offsets rejection on a received signal (SEQ), and b) a single baseband chip (BB) comprising despreading means (DSPR) for despreading a spread signal (SEQ).
摘要:
A method for dynamically clocking one component located into a Wireless telecommunication apparatus comprising a RF transceiver subject to desensizitation by said component EMI, characterized in that it involves the steps of performing an adaptive control on the clock rate of said component so as to locate a wideband noise PSD null just to the left or to the right, in the frequency domain, of the RF transceiver wanted carrier frequency (fw) Particularly, the control is performed by means of the control of programmable frequency dividers, and under the control of a general control unit (UCM) for the purpose of performing a contextual analysis of the current mode of operation of said wireless telecommunications and, in response to said contextual analysis, for determining the fine tuning of the clock rate to be applied to said component.
摘要:
A radio transceiver including—an antenna (201) switch having a control lead (226); —a RF and front end circuit (202) coupled to said antenna switch and operating in at least one 2G mode and at least one 3G mode; —a RF transceiver (209) coupled to said RF front end and operating in at least a first 2G and a second 3G mode; —a baseband (210) communicating with a set of peripherals and external devices; The radio transceiver is characterized by the fact that it includes: —control means (221) for controlling said antenna switch (201) in a isolated mode; —an programmable adaptive filter controlled by said control means for the purpose of introducing at least one notch for eliminating one corresponding spur. The radio transceiver preferably includes means (215) for performing, under control of said control means (221) a FFT computation for the purpose of elaborating a representation, in the time domain, of the different spurs and/or jammers spoiling the received signal when in isolated mode.
摘要:
A communication receiver implements receive space diversity to combine or select signals received from a same source on at least two spatially separated antennas in which the signals may vary in their fading characteristics at a given time. The receiver includes a RF processing module for down-converting and multiplexing the signals and a baseband processing module for converting the signals into digital signals, generating code sequences, producing despreaded and demultiplexed in-phase signals, and retrieving data initially contained within the received signals.