Abstract: The present invention provides a method for a multi-path detection analysis and selectivity of CDMA signals using spread spectrum receivers using a correlation technique. The invention is based on determining by the spread spectrum receiver whether a distortion of a received radio frequency signal, caused by a multi-path component of said received signal, meets a predetermined condition using a pre-selected correlation analysis of said received signal. This invention is generally applicable to global navigation satellite system (GNSS) receivers and it is particularly useful in GNSS receivers, such as GPS (global positioning system) and Galileo receivers. The important goal of this invention is to provide a simple method for identifying signals that are corrupted by multi-path effects, and can be excluded from position calculation in the GNSS receivers.

Abstract: The invention relates to determining a correct code phase of a received, code modulated carrier signal using a correlation portion, a frequency compensation portion, a coherent memory and a non-coherent memory. In order to compensate for a code Doppler effect and/or a carrier Doppler drift effect, a mapping portion maps correlation values either to the coherent memory or to the non-coherent memory. Alternatively, the mapping portion maps correlation values stored in the coherent memory or in the non-coherent memory to new positions. The mapping depends on a frequency compensation applied by the frequency compensation portion and elapsed integration time, and/or on a drift of a frequency offset in correlation values output by said correlation portion.

Abstract: A method for validating detected code modulated signals transmitted by beacons of a positioning system and received by a receiver comprises as a first step performing measurements for the detected beacon signals. Then, at least one of the detected beacon signals is selected as a calibration signal. In a next step, at least one allowed range for results of measurements for detected beacon signals other than the calibration signal are determined based on measurements for the detected calibration signal and on an available reference position of the receiver. Finally, each detection of a beacon signal for which results of performed measurements are outside of an allowed range is rejected. The invention relates equally to a corresponding receiver, to an electronic device comprising such a receiver, to a device cooperating with such a receiver and to a corresponding positioning system.

Abstract: A method for supporting a determination of the correlation between at least one received code modulated signal and at least one available replica code is shown. In order to reduce the total memory size required for such correlations, the method comprises storing signal samples of the at least one received code modulated signal with a first rate in a memory. The stored signal samples are then read with a second rate from the memory for determining a correlation between the read signal samples and samples of the at least one available replica code, wherein the second rate is higher than said first rate. The disclosure relates equally to a corresponding electronic device, to a chip for such an electronic device, to a system comprising such an electronic device and to a corresponding software product.

Abstract: To reduce the complexity of the correlation in a correlation based tracking of a code modulated signal received at a receiver, received samples and available replica samples are aligned to each other and the positions of the samples in the received signal and in the replica code sequences are grouped, each group comprising all positions at which the composition of the values of the samples of all of the replica code sequences is similar. The values of the received samples which are associated to a respective group are combined separately for each group to obtain a respective intermediate result. Then, a correlation value is determined for each replica code sequence by combining the intermediate results obtained for all groups separately for each replica code sequence, taking into account the values of the samples of the replica sequences in the respective group.

Abstract: The invention relates to the reception of code-modulated signals by a receiver. In order to prevent an incorrect synchronization between a received code-modulated signal and an available replica code, partial correlations are performed between a respective subset of samples of the replica code and samples of the received code-modulated signal associated to the respective subset of samples of the replica code at a specific alignment between the received code-modulated signal and the replica code. The results of the partial correlations are then compared to each other, and it may be decided based on this comparison whether the replica code corresponds to a code employed for code-modulating the received code-modulated signal.

Abstract: The present invention provides a method for a flexible multimode operation of spread spectrum receivers, e.g., global navigation satellite system (GNSS) receivers, using a shared circuitry hardware configuration of the receiver for processing of different types of code division multiple access (CDMA) signals. According to said method the receiver utilizes shared channel circuitry to receive signals of different CDMA types providing a flexible multimode operation. The present invention provides a way to select the received signal type for each channel by replacing the dedicated channels with multimode channels suitable to multiple types of receiver signals. The multimode receiver is more flexible to operate in varying reception conditions. By utilizing shared channel circuitry the hardware size is kept small.

Abstract: A ranging receiver (10) including a cellular module (11), for providing time according to a positioning system to enable synchronizing a wireless system to the positioning system. The ranging receiver (10) includes both the cellular module (11) and a main module (12) that provides ranging receiver functionality. When the cellular module (11) receives a time-stamped frame from the wireless system, it sends a trigger signal over a special hardware path to the main module (12), which then relates the time of trigger receipt to time according to the positioning system by calculating a position-velocity-time (PVT) solution, using a local clock (18) to get the difference in time between receipt of the trigger and the instant to which the PVT solution applies, and then communicates to the cellular module (11) when it received the trigger, according to positioning system time.

Abstract: The invention relates to a method for acquiring a receiver (1) into a code modulated spread spectrum signal received by the receiver (1). In the method at least one replica code (r) is used which corresponds to a code used with the modulation having a pre-determined number of chips, and an examination phase is performed, in which a frequency shift of the signal within a selected frequency area is examined, and a code phase of the code used with the modulation is examined. In the method the frequency shift examination is divided into a first estimation phase and a second estimation phase, wherein in the first estimation phase the selected frequency area is divided into a first set of frequencies, and in the second estimation phase a second set of frequencies is examined nearby each frequency of the first set of frequencies.

Abstract: A method, corresponding apparatus, and corresponding system for acquiring a received spread spectrum signal, the received signal having a carrier component at a carrier frequency, a code component having a code period, and a data component, the acquiring including matching the phase of a replica of the code component to the phase of the received code component and also determining any shift in the carrier frequency away from a transmitted carrier frequency, the method including the steps of: performing a first acquisition of the received signal so as to provide an approximately estimated carrier frequency and a phase of the replica and also so as to provide a code-wiped and an approximately carrier-wiped signal; and performing a second acquisition of the approximately carrier-wiped signal, the second acquisition including a substep of data wipe-off involving a squaring or similar operation on a signal derived from the approximately carrier-wiped signal; thereby providing a correction to the approximately esti

Abstract: The invention relates to an apparatus supporting an acquisition of a received code modulated signal by determining the correlation between the received code modulated signal and an available replica code sequence at different code phases. It is proposed that the apparatus comprises a first acquisition engine for selecting code phases which are good candidates for being the code phase at which a received code modulated signal and an available replica code sequence have the highest correlation. The apparatus further comprises a second acquisition engine for performing a refined comparison between a received code modulated signal and an available replica code sequence for each code phase selected by the first acquisition engine. The invention relates equally to a corresponding method and to a system comprising such an apparatus and a network.

Abstract: A method for positioning a wireless communication device includes storing position data relating to one or a plurality of reference areas to at least one data base. It is examined which of said reference areas is located in the vicinity of the wireless communication device, and at least position data about the reference area located in the vicinity of the wireless communication device is retrieved for the wireless communication device. In order to perform the positioning, the method further includes selecting the reference area located in the vicinity of the wireless communication device as the default position of the wireless communication device.

Abstract: The invention relates to a method for estimating the position of a receiver receiving code modulated signals from at least one beacon. The method comprises delimiting a region containing the receiver position based on a code modulated signal received at the receiver from at least one beacon and on available information including at least an initial information on the receiver position. The method further comprises estimating the receiver position as a position within the delimited region which minimizes an error criterion. The invention relates equally to such a receiver, to a system comprising such a receiver and to a corresponding software program product enabling an estimation of the position of a receiver.

Abstract: The present invention relates to a method for determining the position of an electronic device using satellites in a positioning system. In the method, satellite orbit data and a default position for the electronic device are determined. In the method, at least the following steps are taken: a determination step for determining a first time data estimate by using the default position, a computing step for computing an estimate of the code phase of the satellite signal on the basis of the time data estimate, the default position and the satellite orbit data, and a searching step, in which a code-modulated signal transmitted by satellites of a positioning system is received for searching the signal of at least one satellite and for acquiring the signal by using the estimate of the code phase. The invention also relates to a system, in which the method is applied, as well as to an electronic device.

Abstract: The invention relates to a method for attenuating interferences in a positioning receiver, wherein a signal transmitted by the satellites of a positioning system is received, and the received signal is amplified. In the positioning receiver a noise level of the received signal is determined, the existence of interferences is established on the basis of changes of the determined noise level, and the amplification is controlled on the basis of the noise level of the signal received otherwise than during interference. The invention also relates to an electronic device, wherein the method is applied, as well as to a program, with which the method can be implemented in connection with the positioning receiver.

Abstract: A method and apparatus for conserving power in a positioning system receiver using ranging signals to determine a state of motion of the receiver, the method including: a step (32) of performing at least a predetermined number of solutions of the state of motion of the receiver using a filter solution based on a variable mix of models of the motion of the receiver, and of providing the model mix used in each solution; and a step (35) of adopting a partial duty cycle indicating a percentage of time selected receiver components are powered on, based on the mix of models used in successive solutions. Typically, the receiver includes a radiofrequency (RF) front end module and a baseband processor module and the selected components that are powered on and off to save power typically include the RF front end module and the baseband processor module.

Abstract: A ranging receiver (10) including a cellular module (11), for providing time according to a positioning system to enable synchronizing a wireless system to the positioning system. The ranging receiver (10) includes both the cellular module (11) and a main module (12) that provides ranging receiver functionality. When the cellular module (11) receives a time-stamped frame from the wireless system, it sends a trigger signal over a special hardware path to the main module (12), which then relates the time of trigger receipt to time according to the positioning system by calculating a position-velocity-time (PVT) solution, using a local clock (18) to get the difference in time between receipt of the trigger and the instant to which the PVT solution applies, and then communicates to the cellular module (11) when it received the trigger, according to positioning system time.

Abstract: A method for validating detected code modulated signals transmitted by beacons of a positioning system and received by a receiver comprises as a first step performing measurements for the detected beacon signals. Then, at least one of the detected beacon signals is selected as a calibration signal. In a next step, at least one allowed range for results of measurements for detected beacon signals other than said calibration signal are determined based on measurements for the detected calibration signal and on an available reference position of the receiver. Finally, each detection of a beacon signal for which results of performed measurements are outside of an allowed range is rejected. The invention relates equally to a corresponding receiver, to an electronic device comprising such a receiver, to a device cooperating with such a receiver and to a corresponding positioning system.

Abstract: The invention relates to a method for positioning a receiver receiving code modulated signals transmitted by satellites and formed by an individual code for each satellite. In order to provide a reliable reference position for the receiver, it is proposed that in a first step, a reference position for said receiver is calculated based on frequency measurements of said code modulated signals. This reference position can then be employed in a second step for determining the accurate position of the receiver. The invention equally relates to such a receiver, to positioning means, to a computing server and to a positioning system comprising means for realizing the proposed method.

Abstract: The invention relates to a method for determining the time of transmission of a signal part of a code modulated signal transmitted by a beacon of a positioning system and received by a receiver of the positioning system. In order to enable such a determination in weak signal conditions, it is proposed that measured subcomponents of the time of transmission of at least two signal parts are compared with corresponding predicted subcomponents in a way resulting in a combined difference for all signal parts. The comparison is performed for a plurality of assumed errors in the predicted subcomponent. The accurate time of transmission of a signal part is then determined based on the determined error value which results in the smallest combined difference. The invention relates equally to a corresponding receiver and to a corresponding positioning system.