Abstract: A radio link transmission method that comprises transmitting data on a plurality of radio channels. The method allocates a portion of the capacity of each radio channel for transmission of identical data on the plurality of radio channels. The remaining capacity of each radio channel is allocated for transmission of unique data, which is different for each radio channel. The method further transmits the identical data on each radio channel of the plurality of radio channels, and transmits the unique data in the respective radio channels of the plurality of radio channels.

Abstract: A method and system for measuring the concentration of a gas component in a measuring gas a provided. The wavelength of a light source is modulated with a modulation signal at a modulation frequency, while the wavelength is swept over an interaction feature of a sample. The intensity of the light source is further modulated at a wavelength outside the interaction feature with a burst signal, where an N-th harmonic of the burst frequency coincides with an M-th harmonic of the modulation frequency. The light is passed to the sample and thereafter to a detector. The detector output is demodulated at the M-th harmonic, and the demodulated detector output is normalized by calculating the ratio between a demodulated detector output portion derived from the light modulated with the modulation signal and another demodulated detector output portion derived from the light modulated with the burst signal.

Abstract: In a wavelength modulation spectroscopy method and system the wavelength of a light source is modulated with a frequency f0. The light of the light source is passed to a sample for interacting and thereafter detected and demodulated at a higher harmonic Nf0. To suppress non-linearities in the modulation of the wavelength of the light source a portion of the light (15) of the light source (14) is passed to a monitor detector (17). The monitor detector output is demodulated at said higher harmonic Nf0, and the modulation of the light source (14) is predistorted at said higher harmonic Nf0 in dependence on said demodulated monitor detector output.

Abstract: In a wavelength modulation spectroscopy method and system the light of a tunable light source is modulated with a frequency f0, while the wavelength is swept over an interaction feature of a sample to be measured. The light of the light source is passed to a sample for interacting and thereafter detected and demodulated at a higher harmonic Nf0. To suppress effects of fluctuations of the optical transmission of the system on the measurement, originating from varying dust loads, high temperature, gas turbulence etc. in the measurement path (3), a burst signal in form of an envelope modulated pilot tone is added to the modulation of the light (1) of the light source (2) synchronously with the wavelength sweeps at a wavelength outside the interaction feature of the sample. The injected burst signal is at the detection frequency Nf0, where N?2, and is detected together with the measured spectrum from the sample and act as absorption normal, which the spectrum can be calibrated against.

Abstract: In a wavelength modulation spectroscopy method and system the light of a tunable light source is modulated with a frequency f0, while the wavelength is swept over an interaction feature of a sample to be measured. The light of the light source is passed to a sample for interacting and thereafter detected and demodulated at a higher harmonic Nf0. To suppress effects of fluctuations of the optical transmission of the system on the measurement, originating from varying dust loads, high temperature, gas turbulence etc. in the measurement path (3), a burst signal in form of an envelope modulated pilot tone is added to the modulation of the light (1) of the light source (2) synchronously with the wavelength sweeps at a wavelength outside the interaction feature of the sample. The injected burst signal is at the detection frequency Nf0, where N?2, and is detected together with the measured spectrum from the sample and act as absorption normal, which the spectrum can be calibrated against.

Abstract: In a wavelength modulation spectroscopy method and system the wavelength of a light source is modulated with a frequency f0. The light of the light source is passed to a sample for interacting and thereafter detected and demodulated at a higher harmonic Nf0.