Abstract: A heterodyne receiver structure comprises a frequency conversion block arranged to convert an incoming analog radio frequency (RF) signal to an analog intermediate frequency (IF) signal; a filter block arranged to filter said analog IF signal; and an analog-to-digital (AD) converter block arranged to convert said filtered analog IF signal to a digital signal, wherein the AD converter block (309) is arranged to convert the filtered analog IF signal to the digital signal by using a sampling frequency (fs) which is at least N times a maximum bandwidth of the filtered analog IF signal, wherein the frequency spectrum from zero to the sampling frequency is divided into N frequency zones of equal width, wherein N is an even positive number higher than two; the frequency conversion block (304) is arranged to convert the incoming analog RF signal to the analog IF signal such that the analog IF signal is located in any of the N/2-1 frequency zones having lowest frequency; and the filter block (306-308) is arranged to l

Abstract: A heterodyne receiver structure comprises a frequency conversion block arranged to convert an incoming analogue radio frequency (RF) signal to an analogue intermediate frequency (IF) signal; a filter block arranged to filter said analogue IF signal; and an analogue-to-digital (AD) converter block arranged to convert said filtered analogue IF signal to a digital signal, wherein the AD converter block (309) is arranged to convert the filtered analogue IF signal to the digital signal by using a sampling frequency (fs) which is at least N times a maximum bandwidth of the filtered analogue IF signal, wherein the frequency spectrum from zero to the sampling frequency is divided into N frequency zones of equal width, wherein N is an even positive number higher than two; the frequency conversion block (304) is arranged to convert the incoming analogue RF signal to the analogue IF signal such that the analogue IF signal is located in any of the N/2-1 frequency zones having lowest frequency; and the filter block (306-3

Abstract: The present solution relates to a method in a base station (110) for generating radio frequency. The base station (110) comprises a base station unit (125) connected to a tower mounted amplifier (122) via a feeder (127). A signal from the base station unit (125) is received, via a serial interface over the feeder (127), in the tower mounted amplifier (122). A frequency reference signal is extracted from the received signal. The extracted frequency reference signal is provided to a radio frequency synthesizer (210). The radio frequency synthesizer (210) is comprised in the tower mounted amplifier (122). A radio frequency is generated in the radio frequency synthesizer (210) using the extracted reference signal.

Abstract: A variable bandwidth receiver uses allocated bandwidth more efficiently and ensures that blocking signals do not overload receiver components. The receiver includes multiple branches for receiving a first bandwidth signal. Each receiver branch has a filter for passing signals in a frequency band corresponding to a second bandwidth less that the first bandwidth and an analog-to-digital converter for converting the baseband signal into a digital signal. A controller digitally combines the digital signals from two or more of the receiver branches to produce a received signal having a bandwidth substantially wider than the first bandwidth. Because combining is done after analog-to-digital conversion in the digital domain, the controller can combine the digital signals from two or more of the receiver branches having adjacent corresponding frequency bands without the normal guard band separating them.

Abstract: Radio transmissions to multiple radio terminals are improved using scheduled backoff of a multi-signal power amplifier. A radio channel quality associated with each of the radio terminals is determined. First signals for first radio terminals associated with a better channel quality are amplified by a power amplifier during a first time period resulting in a first composite output signal. Second signals for second radio terminals associated with a lower channel quality are amplified by the power amplifier during a second time period resulting in a second composite output signal. Transmission during the first time period occurs at a first power level, e.g., mean power, that is associated with a lower probability of clipping the first composite output signal. During the second time period, the second composite signal is transmitted at a second power level, e.g., mean power, higher than the first power level which improves reception at the second terminals.

Abstract: The present invention relates to a method and arrangement for enhancing efficiency of transmission using Single Channel-Frequency Division Multiple Access (SC-FDMA). The method comprises the step of: applying a Discrete Fourier Transformation (DFT) of time signal providing No samples in a first resulting signal, inserting N1 pilot tones in said resulting signal providing No+N1 tones, Interpolating said signal provided with No+N1 tones to a required size, N, by insertion of zero bins in a middle section of said DFT providing a modified signal, applying Inversed Fast Fourier Transform (IFFT) on said modified signal, and performing a cyclic prefix insertion before transmitting the modified signal. Thus, similar equalising techniques as for OFDM are possible for efficacy signal reception.

Abstract: A solution is disclosed for achieving a functional complex base-band adaptive digital nonlinear device model providing RF-power amplifier distortion (i.e. linearization or pre-distortion) minimizing distortion characterization including memory effects. The present inventive solution is based on real device non-linear performance observations and the physical cause for the distortion is compensated in the application. This also means that a pre-distorter digital circuit is derived to have the inverse functionality of the digital device model. The model and the digital pre-distortion circuit are designed in such way, that function blocks are connected in cascade. Each function block is then designed to handle a certain type of distortion performance and can be optimized individually. The model gives possibilities to describe and evaluate different device properties.

Abstract: Radio transmissions to multiple radio terminals are improved using scheduled backoff of a multi-signal power amplifier. A radio channel quality associated with each of the radio terminals is determined. First signals for first radio terminals associated with a better channel quality are amplified by a power amplifier during a first time period resulting in a first composite output signal. Second signals for second radio terminals associated with a lower channel quality are amplified by the power amplifier during a second time period resulting in a second composite output signal. Transmission during the first time period occurs at a first power level, e.g., mean power, that is associated with a lower probability of clipping the first composite output signal. During the second time period, the second composite signal is transmitted at a second power level, e.g., mean power, higher than the first power level which improves reception at the second terminals.

Abstract: In the present invention a completely different approach for modeling of non-linear devices or processes is used. A cascade of blocks each depending on a non-linearity parameter are utilized both in non-linear modeling and a pre-distorter design. The new non-linear model description can be used for characterization of a non-linear system or for linearizing a non-linear system. Application to a Communications System Multi-carrier Amplifier is shown as an application example. Also for other application areas of the new mathematical method is feasible echo-canceling, non-linear communications channels etc. Parameter extractions and tables for the new model do not give multiple dimensional mathematical solutions for parameter extractions as in prior art.

Abstract: The present invention relates to radio transmission of bursts in for example a TDMA cellular radio system. The burst starts with a ramping up period, ends with a corresponding ramping down ramping down period and with the pay-load information therebetween. The ramp form is created in a ramp generator (13) which gives a multiplication value to multiply the digital information to be transmitted in multipliers (15, 16). The multiplied values are converted into analogue form and amplified before being transferred to the antenna (21). Output power and temperature of the transmitting equipment are measured (22, 23) and used to update the output power levels during the next burst.

Abstract: In the present invention a completely different approach for modeling of non-linear devices or processes is used. A cascade of blocks each depending on a non-linearity parameter are utilized both in non-linear modeling and a pre-distorter design. The new non-linear model description can be used for characterization of a non-linear system or for linearizing a non-linear system. Application to a Communications System Multi-carrier Amplifier is shown as an application example. Also for other application areas of the new mathematical method is feasible echo-canceling, non-linear communications channels etc. Parameter extractions and tables for the new model do not give multiple dimensional mathematical solutions for parameter extractions as in prior art.

Abstract: A solution is disclosed for achieving a functional complex base-band adaptive digital nonlinear device model providing RF-power amplifier distortion (i.e. linearization or pre-distortion) minimizing distortion characterization including memory effects. The present inventive solution is based on real device non-linear performance observations and the physical cause for the distortion is compensated in the application. This also means that a pre-distorter digital circuit is denved to have the inverse functionality of the digital device model. The model and the digital pre-distortion circuit are designed in such way, that function blocks are connected in cascade. Each function block is then designed to handle a certain type of distortion performance and can be optimized individually. The model gives possibilities to describe and evaluate different device properties.

Abstract: The present invention relates to radio transmission of bursts in for example a TDMA cellular radio system. The burst starts with a ramping up period, ends with a corresponding ramping down ramping down period and with the pay-load information therebetween. The ramp form is created in a ramp generator (13) which gives a multiplication value to multiply the digital information to be transmitted in multipliers (15, 16). The multiplied values are converted into analogue form and amplified before being transferred to the antenna (21). Output power and temperature of the transmitting equipment are measured (22, 23) and used to update the output power levels during the next burst.

Abstract: A transmitter subsystem is disclosed whereby the output frequency spectrum of a DDS device, for use in the transmitter subsystem, is frequency multiplied to achieve greater frequency coverage at the RF bands. In one embodiment of the present invention, a DDS device is structured in such a way that the DDS output signal spectra can be multiplied directly for direct conversion to RF or IF bands. As such, the requirements placed on the DACs in the DDS device are lessened, because the DACs require much lower sampling frequencies than those used in the existing technology. Also, the requirements placed on the implemented bandpass filters used for image rejection in the applied upconverters are lessened, because of the larger frequency difference created between the desired output and the image frequency band. In a second embodiment of the present invention, a DDS device is also structured in such a way that multiplication of the baseband spectra can be accomplished at the IF.