摘要:
The present invention relates to methods and apparatuses as well as a measurement report signal for reporting measurements on ranging signals (RS1-RS4) received by a mobile station from satellites (SV1-SV4) or calculating a position based on such measurements, wherein each of said ranging signal comprises a stream (201) of data bits (202) spread by a spreading code (203). After synchronizing (501) to data bit edges in the stream of data bits on a ranging signal, a position in time modulo the data bit length for said stream of data bits with respect to a selected point in time is measured (502). The measured position in time could be used by the apparatus performing the measurements on the received ranging signals for calculating (504) the position of the mobile station. Alternatively the apparatus could transmit (503) a wireless signal including data representing said measured position in time, allowing the mobile station position to be determined in another apparatus (101).
摘要:
Reliable and efficient search windows are provided by allowing the adaptation of the code search window to be dependent on inaccuracy measures of relations between a cellular frame time and a satellite reference time. This inaccuracy is calculated in a positioning node (21) of the cellular communications system (1), preferably by filtering of measurements received from user equipments. Linear trend Kalman filtering followed by post processing of estimation errors is presently preferred. In order to ensure non-ambiguous interpretation of the received time stamps of received satellite signals (55) provided by user equipments (10), a pseudo propagation delay is computed in both the user equipment (10) and the positioning node (21) based on GPS acquisition assistance data. The GPS time stamp is then defined referring to the determined pseudo propagation delay. In a preferred embodiment, the pseudo propagation delay is assured to be situated within a pre-determined time interval.
摘要:
A method for noise rise estimation in a wireless communication system comprises measuring (210) of received total wideband power of an antenna a plurality of times. An estimate of a noise floor measure is computed (212) based on at least a number of the measured received total wideband powers of the antenna. Interference whitening of a received signal is performed (214) per user for a multitude of users. A useful signal power per user after the interference whitening, preferably Frequency Domain Equalization, is determined (216). A noise rise measure per user is calculated (220), based at least on the useful signal power per user and the noise floor measure. The calculation in turn comprises compensation of the noise rise measure per user for the effects of the interference whitening. An arrangement for noise rise estimation is adapted for such a method. A radio base station comprises such an arrangement.
摘要:
A method for equalizing a received radio signal in a WCDMA system, comprises receiving (210), in a radio receiver, of a digital radio signal spread by scrambling codes. A channel estimation is performed (230) on the received digital radio signal for a plurality of channels. The received digital radio signal is in an equalizer equalized (240) into an equalized digital radio signal. This equalizing is performed by combining a plurality of part signals, deduced from the digital radio signal, with a respective delay and a respective combining weight. The equalizing (240) comprises provision of the combining weights based on a signal impairment matrix having elements compensated for systematic colouring caused by said scrambling codes.
摘要:
A method for uplink channel estimation comprises providing (210) of a channel state model in a channel estimator. An up-link radio signal of a present time slot is obtained (220) in the channel estimator as well as a series of transmit power control commands (230) issued for controlling a transmit power of the uplink radio signal. A delay between the time a transmit power control command is issued and the time that the transmit power control command is applied is estimated (232) based on measurements of the particular received uplink radio signal. Channel states are adapted (234) based on a transmit power control command compatible with the estimated delay. After the adaptation, channel states of the present time slot are estimated (240) in the channel estimator, by tracking the demodulated uplink radio signal with the channel state model. A channel estimator performing such method is also described.
摘要:
In a method of providing real time difference determination for a mobile terminal in a telecommunication system, comprising a plurality of eNodeBs in communication with a core network, each eNodeB having a plurality of associated cells, each cell potentially servicing one or more mobile terminals, determining S1O a first timing advance value representative of a first geographical distance measure between the mobile terminal and a first serving eNodeB prior to a handover to a second serving eNode B, determining S20 a second timing advance value representative of a second geographical distance measure between the mobile terminal and the second eNodeB after the handover. Subsequently, determining S30 a time of arrival measure between the mobile terminal and at least two eNodeBs, and signaling S40 representations of the determined first and second geographical distance measures and the determined time of arrival measures for said mobile terminal to at least said second eNodeB, together with a respective unique identification parameter of the at least two eNodeBs, wherein determination of real time differences is enabled based on at least the signaled representations.
摘要:
The position of a mobile device served in a cell of a serving node of a wireless communication network is estimated by estimating an angle-of-arrival (AoA) between the mobile device and the serving node based on a precoding matrix indicator (PMI) determined for the serving node in a downlink direction or for the mobile device in an uplink direction. Also estimated is the AoA between the mobile device and a non-serving neighbor node of the wireless communication network based on a PMI determined for the neighbor node in the downlink direction or for the mobile device in the uplink direction. The downlink and/or uplink AoA estimation can be further enhanced by employing interference cancellation in the mobile device and in the radio node, respectively. The position of the mobile device is estimated based on the estimated AoAs.
摘要:
A wireless device (24) receives a reference signal over a radio channel (21). The reference signal may be Positioning Reference Signals (PRS) and/or Common Referencing Signals (CRS), and may be transmitted from a transmitter (22). The wireless device (24) comprises a correlator (100); a reference signal detector (102); a threshold selector (106); and a reference signal analyzer (108). The correlator (100) use a signal received from the radio channel (21) and a replica of the reference signal to provide a correlator output value. The reference signal detector (102) compares the correlator output value with a threshold value to detect presence of a reference signal, and to estimate an arrival time of the reference signal. The threshold selector (106) adapts the threshold value to at least an estimate of a relative amount of noise and interference power in the received signal.
摘要:
GPS and A-GPS based positioning methods can be used to determine UE locations to enable location based services to be provided. However, if a UE does not have such receivers or the wireless network is not able to provide assistance, these methods will not be applicable. An alternative is to use OTDOA measurements using positioning reference signals transmitted by cells of the network. By optimizing the set of cells transmitting their positioning reference signals on different positioning occasions and properly configuring the muting patterns, interference can be minimized and the UE location can be readily determined.
摘要:
Method and apparatus are provided for processing a received signal for making a symbol estimate of a symbol included in a signal transmitted in a Multiple-Input-Multiple-Output (MIMO) system. In an example mode, the method comprises (1) providing at least a sub-set of precoding matrices which are candidates for use in transmission of an interfering signal in a MIMO system; (2) using the received signal and plural candidates of the subset to determine corresponding plural covariance matrices, each of the plural covariance matrices being formed using a corresponding candidate precoding matrix; (3) determining which of the candidates is a trace minimizing candidate which is associated with one of the plural covariance matrices that has a minimum trace value; (4) forming a weighting matrix using the trace minimizing candidate; and (5) using the weighting matrix to make the symbol estimation.