Abstract: Each of a plurality of transmitters, which are distributed at fixed locations of a site, regularly transmits radio signals. A mesh node performs measurements on radio signals transmitted by at least one transmitter and transmits messages including results of the measurements. The mesh node belongs to a plurality of mesh nodes, each configured to monitor at least one environmental parameter at the site. A gateway node receives messages transmitted by the mesh node directly and/or via at least one other mesh node of the plurality of mesh nodes, wherein each of the plurality of mesh nodes is configured to receive messages from other mesh nodes of the plurality of mesh nodes and to forward received messages. The gateway node transmits received messages to a server that is configured to monitor mesh nodes at the site based on results of measurements.

Abstract: Each of a plurality of transmitters, which are distributed at fixed locations of a site, regularly transmits radio signals. A mesh node performs measurements on radio signals transmitted by at least one transmitter and transmits messages including results of the measurements. The mesh node belongs to a plurality of mesh nodes, each configured to monitor at least one environmental parameter at the site. A gateway node receives messages transmitted by the mesh node directly and/or via at least one other mesh node of the plurality of mesh nodes, wherein each of the plurality of mesh nodes is configured to receive messages from other mesh nodes of the plurality of mesh nodes and to forward received messages. The gateway node transmits received messages to a server that is configured to monitor mesh nodes at the site based on results of measurements.

Abstract: Each of a plurality of transmitters, which are distributed at fixed locations of a site, regularly transmits radio signals. A mesh node performs measurements on radio signals transmitted by at least one transmitter and transmits messages including results of the measurements. The mesh node belongs to a plurality of mesh nodes, each configured to monitor at least one environmental parameter at the site. A gateway node receives messages transmitted by the mesh node directly and/or via at least one other mesh node of the plurality of mesh nodes, wherein each of the plurality of mesh nodes is configured to receive messages from other mesh nodes of the plurality of mesh nodes and to forward received messages. The gateway node transmits received messages to a server that is configured to monitor mesh nodes at the site based on results of measurements.

Abstract: The invention relates to a direct conversion receiver and a method in a direct conversion receiver for processing received radio signals that are modulated and centered at a carrier frequency, the modulation extending a sideband above and below the carrier frequency. The method comprises the steps of mixing a local oscillator frequency signal with said received radio signals for generating baseband frequency signals; filtering out generated disturbing direct current (DC) components of said baseband signals centered at the zero frequency; setting said local oscillator frequency signal equal to or about the carrier frequency plus an offset frequency, said offset frequency being equal to the difference between the carrier frequency and a null frequency, said null frequency centered at a notch of said sideband; and centering said notch at the zero frequency of said baseband signals through mixing. The invention relates particularly to suppression of DC offsets generated in the receivers.

Abstract: The invention relates to a direct conversion receiver and a method in a direct conversion receiver for processing received radio signals that are modulated and centered at a carrier frequency, the modulation extending a sideband above and below the carrier frequency. The method comprises the steps of mixing a local oscillator frequency signal with said received radio signals for generating baseband frequency signals; filtering out generated disturbing direct current (DC) components of said baseband signals centered at the zero frequency; setting said local oscillator frequency signal equal to or about the carrier frequency plus an offset frequency, said offset frequency being equal to the difference between the carrier frequency and a null frequency, said null frequency centered at a notch of said sideband; and centering said notch at the zero frequency of said baseband signals through mixing. The invention relates particularly to suppression of DC offsets generated in the receivers.

Abstract: The invention relates to a method for implementing a transceiver, in which method radio-frequency signals are transmitted and received with a transceiver for communicating information. A radio-frequency signal received at a receiving stage is subjected to at least a first filtering step, in which a desired receiving signal is separated from the signal with a filter. A signal to be transmitted at a transmission stage is subjected to at least a second filtering step, in which a desired transmission signal is separated from the signal with a filter, to be transmitted. In the method, the same filter is used at least partly in said first and second filtering steps.

Abstract: A method and a device for reducing cycle slips resulting from frequency hops in a wireless communication device. In the method, a first signal pulse is received, which first signal pulse is either said reference signal pulse or said signal pulse to be compared, a second signal pulse is received, which second signal pulse is from another source than said first signal pulse, a control voltage is generated for controlling a voltage controlled oscillator in response to a phase difference between said first received and said second received signal pulses. At a time instant between the reception of said first and said second signal pulses, a constant voltage is added to said control voltage on receiving additionally one signal pulse, which is the same type as said first signal pulse. After receiving said second signal pulse, said constant voltage is removed from said control voltage on receiving at least one signal pulse, which is the same type as said second signal pulse.

Abstract: The invention relates to a method for tuning an adjustable oscillator, in which oscillator at least one resonance circuit is used. The frequency of the oscillator is adjusted by changing the resonance frequency of the at least one resonance circuit by means of a control signal for which a minimum value and a maximum value are selected. In the method at least one target value is selected for the control signal, the frequency of the adjustable oscillator is adjusted to substantially correspond to the target value and the value of the control signal and the target value are compared. When the value of the control signal is substantially different from the target value, a tuning signal is produced to change the resonance frequency of the at least one resonance circuit.

Abstract: A method and a device for reducing cycle slips resulting from frequency hops in a wireless communication device. In the method, a first signal pulse is received, which first signal pulse is either said reference signal pulse or said signal pulse to be compared, a second signal pulse is received, which second signal pulse is from another source than said first signal pulse, a control voltage is generated for controlling a voltage controlled oscillator in response to a phase difference between said first received and said second received signal pulses. At a time instant between the reception of said first and said second signal pulses, a constant voltage is added to said control voltage on receiving additionally one signal pulse, which is the same type as said first signal pulse. After receiving said second signal pulse, said constant voltage is removed from said control voltage on receiving at least one signal pulse, which is the same type as said second signal pulse.

Abstract: The invention relates to a direct conversion receiver and a method in a direct conversion receiver for processing received radio signals that are modulated and centered at a carrier frequency, the modulation extending a sideband above and below the carrier frequency. The method comprises the steps of mixing a local oscillator frequency signal with said received radio signals for generating baseband frequency signals; filtering out generated disturbing direct current (DC) components of said baseband signals centered at the zero frequency; setting said local oscillator frequency signal equal to or about the carrier frequency plus an offset frequency, said offset frequency being equal to the difference between the carrier frequency and a null frequency, said null frequency centered at a notch of said sideband; and centering said notch at the zero frequency of said baseband signals through mixing. The invention relates particularly to suppression of DC offsets generated in the receivers.

Abstract: The invention relates to a method for tuning an adjustable oscillator, in which oscillator at least one resonance circuit is used. The frequency of the oscillator is adjusted by changing the resonance frequency of said at least one resonance circuit by means of a control signal for which a minimum value and a maximum value are selected. In the method at least one target value is selected for the control signal, the frequency of the adjustable oscillator is adjusted to substantially correspond to said target value and said value of the control signal and the target value are compared. When the value of the control signal is substantially different from the target value, a tuning signal is produced to change the resonance frequency of said at least one resonance circuit.

Abstract: A synthesizer arrangement for generating signals simultaneously, the arrangement comprising as an input a frequency reference signal generated with stable crystal oscillator means. The arrangement comprises first synthesizer means arranged to independently generate a first signal from the frequency reference signal, and as their input a first control signal controlling the generation, on the basis of which the first signal is modified independently, and second synthesizer means arranged to independently generate a second signal from the frequency reference signal, and as their input a second control signal controlling the generation, on the basis of which the second signal is modified independently.

Abstract: The invention relates to a method for implementing a transceiver, in which method radio-frequency signals are transmitted and received with a transceiver for communicating information. A radio-frequency signal received at a receiving stage is subjected to at least a first filtering step, in which a desired receiving signal is separated from the signal with a filter. A signal to be transmitted at a transmission stage is subjected to at least a second filtering step, in which a desired transmission signal is separated from the signal with a filter, to be transmitted. In the method, the same filter is used at least partly in said first and second filtering steps.