Abstract: A base station (1) in a radio communication system is provided with an antenna array 2, 3 for communication with a plurality of mobile stations (4, 5). The transmissions of the base station (1) are optimised by adjusting the phase between the signals transmitted by each antenna (2, 3) so that the product of the propagation channel estimates is maximised. The invention has particular application to CDMA-TDD modes of operation where it has been shown to perform favourably in comparison with known transmit diversity techniques. A further advantage is that it does not require added complexity in the channel estimation at each mobile station (4, 5).

Abstract: Reception points arranged inside an observation region are divided into groups for a plurality of reception points, and a hierarchical structure in which a reception point group having a large scale involves a smaller scale of plural reception point groups is structured in advance. In accordance with determination criteria defined in advance, the reception point groups involving the reception points which need reception determination processing with a ray are successively screened from the reception point groups having a large scale to a smaller scale of reception point groups, and the final reception determination of a ray and the reception points is applied only to the reception points involved in the screened reception point groups.

Abstract: The Doppler spreads of the received signals in a MIMO, SIMO or MISO mobile communication system are estimated from the derivatives of the path transfer function envelopes for the received signals. The estimated Doppler spreads is used to estimate the speed of the mobile station.

Abstract: A system, method, apparatus, means, and computer program code for improving accuracy of radio timing measurements. According to embodiments of the present invention, a terminal may obtain a measurement of each of a plurality of radio transmission sources at a distinct instance in time. In addition, a radio timing measurement for a common radio source is obtained for each of the distinct instants in time. The result will be a pair of radio timing measurements for each distinct instance in time containing smaller adjustment errors than radio timing measurements for all radio sources obtained for one common instant in time. The pairs of radio timing measurements can be used to more accurately support applications in which the geographic position of the terminal is obtained.

Abstract: A system, apparatus, and method for determining the distance between two objects using an indirect propagation delay measurement is disclosed. A frequency hopping scheme (such as the Bluetooth™ technology) is used to measure the relative phase offset of the received signal between the various frequencies. For a given distance between the objects, the phase offset vs. frequency curve is a straight line with the slope dependent upon the measured distance. After the phase of the received signals is detected, the data is plotted on a curve and the slope is calculated. A wireless slave device remains phase locked with another device in a half-duplex communication mode by employing a low-drift phase locked loop employing a voltage controlled crystal oscillator. The phase locked loop further employs a mechanism that provides immunity from transitory phase slip at a time when the loop is opened.

Abstract: A tuned wave phased array includes a plurality of spaced transmitter elements, a signal generator that produces an activation signal for activating the transmitter elements to transmit a guided wave in an associated medium and a delay circuit for sequentially delaying the activation of at least one of the transmitter elements for creating constructive interference of a selected mode of the wave propagating in the medium, thereby boosting the selected mode of the wave.

Abstract: A method utilizing statistical interpolation techniques to analyze and simulate the spatial variability and continuity of radio frequency data collected from a wireless cellular system. The method is used for cellular system planning and management. After installation and setup of cellular base stations, further analysis and refinement of RF data is implemented to determine signal coverage of the tower, location of RF holes in system, reuse of frequencies, and overlapping RF signals between two or more towers causing interference. The method analyzes raw RF power data that is collected by drive testing a sample of roads in a cellular system. A geostatistical model of the RF propagation at a cellular system is determined through kriging. The RF path loss trend estimation is extracted from each the raw data and modeled to describe data variability across the entire cellular system ares. An estimated path loss signal map is then prepared for any area of interest within a cellular system.

Abstract: An apparatus, system and method for measuring timing of a signal transmitted from a wireless base station antenna. The apparatus and system include a wireless base station antenna that transmits a first signal, and a transmission timing measurement apparatus having a first antenna and a second antenna that receives an accurate time value and the first signal, and that outputs an offset of the first signal from the accurate time value. The method includes receiving an accurate time, receiving the reception time transmitted from the wireless base station antenna, receiving the reception time value and the accurate time value, and comparing of the reception time value and the accurate time value.

Abstract: In a signal transmission system made up of a transmission section, a receive section and an optical fiber installed between the transmission section and the receive section, a harmonic producing circuit and a harmonic phase shifting circuit are provided on the downstream side of an FM modulator. The harmonic producing circuit superimposes a harmonic of an FM signal on the FM signal, and the harmonic phase shifting circuit shifts the phase of the harmonic. This arrangement compensates a group delay deviation occurring in system components when an AM signal or QAM signal is modulated into an FM signal or PM signal in a modulator and then transmitted to be demodulated in a demodulator, thereby improving transmission quantity.

Abstract: A method for testing the function of a mobile station includes starting the generation and transmission of uplink data to a testing apparatus in response to a downlink message of a certain protocol layer received from the testing apparatus. The transmission is controlled by a test procedure determined for the protocol layer in the mobile station, where the test procedure is activated by the message. The mobile station is intended to operate in a packet switched communication network based on a cellular network where the mobile station includes means for receiving downlink data from the testing apparatus, means for transmitting uplink data to the testing apparatus, and protocol means for generating and processing data.

Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.

Abstract: A system and method for dynamically calibrating a base station in a wireless communication system, is presented herein. In accordance with an embodiment of the invention, the system includes a base station for transmitting, receiving, and processing communication signals and a wireless communication device for communicating with the base station. The wireless communication device is configured to determine its location (e.g., using GPS information), to detect the arrival time of a first signal transmitted from the base station, and to calculate a line-of-sight (LOS) delay corresponding to the LOS distance between the wireless communication device and the base station. The LOS distance calculation is based on the base station location information and the wireless communication device location information.

Abstract: A method of determining the location of a user equipment includes determining a round trip time for downlink from at least three nodes to a user equipment, determining the transmission timing delay at the user equipment for the round trip time of each of the three nodes, and determining a distance from each of the at least three nodes using the round trip time and the transmission timing delay.

Abstract: The invention relates to a method for estimating time of arrival of radio signals in particular as used for location determination. A known method of determining the location of a subscriber unit (401) calculates a number of ranges based on the distance from base stations (403,405,407) with known location. The ranges are calculated from time of arrival estimates of the signals from the different base stations but a significant source of error is the multipath signal components typical in for example cellular mobile communication systems. According to the invention, the effect of multipath is mitigated by selecting a subset of signals based on a time of arrival estimate of each of the signals. An averaged time of arrival estimate with improved accuracy is then determined from the selected subset. A typical use of the invention is for location determination in a cellular mobile communication system.

Abstract: A method and system for estimating the location of a mobile station in a telecommunications network having a reference base station and a plurality of neighboring base stations. At the beginning of the E-OTD measurement, the mobile station may be provided with the expected OTD values in the reference base station site, possibly instead of RTD values of the neighboring base stations, to make it possible for the mobile station to calculate the uncertainty in the measured OTD due to its unknown location. Alternatively, the network provides the mobile station the expected OTD values in its current location, and the estimated uncertainty of those values. When the uncertainty is greater than a predetermined value, the mobile station makes E-OTD measurements based on the SCH burst. Otherwise, the mobile station makes measurements based on normal/dummy bursts, and/or aligns the time window for taking samples from signals received from neighboring base stations.

Abstract: A method is disclosed for operating a wireless TDMA communications system. The method includes steps of monitoring a propagation delay of a mobile station; and when the propagation delay exceeds a predetermined limit, changing by a time slot unit a value of one or both of Tta1 and Ttb1, wherein Tta1 is a minimum number of time slots allowed between the end of a last, previous receive time slot and a first, next transmit time slot, when a channel measurement is to be performed in between, and wherein Ttb1 is a minimum number of time slots allowed between the end of a last, previous receive time slot and a first, next transmit time slot.

Abstract: An optimized method for the transmission of multimedia contents between a multimedia content transmitter and a multimedia content receiver in a mobile radio network transmitting a multimedia content description vector from the transmitter to the receiver, calculating a pertinence score of the content from the description vector and as a function of a user profile associated with a user of the receiver, and recovering, at the explicit request of the receiver, a block or blocks of the content not received by the receiver, with a priority depending on the pertinence score associated with the content to which the missing block(s) belong(s).

Abstract: This invention pertains in general to a method of synchronizing remote stations in a communications system and, more particularly, to a method for measuring delay between two remote stations in a communications system. A method of measuring delay between a first station and a second station in different localities in a communications system that includes transmitting a first signal from the first station to the second station and simultaneously resetting a counting clock in the first station, receiving a delayed first signal at the second station, transmitting the delayed first signal to the first station, receiving a further delayed first signal at the first station and simultaneously stopping the counting clock, calculating the number of counts elapsed in the counting clock between the resetting and the stopping of the counting clock, wherein each count of the counting clock equals the period of the counting clock, and multiplying the number of counts with the period of the counting clock.

Abstract: A computing system (36) provides a network designer with a mechanism for adaptively predicting the propagation of a radio wave (22) along radials (24) emanating from a base station (26) in a wireless communication environment (20). The computing system (36) includes executable code in the form of a propagation prediction process (58, 130). The propagation prediction process (58, 130) selects segments (78) of a selected one of the radials (24) on a per segment basis and ascertains a propagation environment (28, 30, 32, 34) through which the selected segment (78) traverses. The process (58, 130) chooses, in response to a switching parameter (88, 90, 92), a propagation model (62, 64, 66, 68) from a collection of propagation models (60) that is best suited for predicting the propagation of the radio wave (22) at the selected segment (78).

Abstract: The invention provides a method of determining an adaptive channel estimation by providing a channel estimate, determining at least one channel condition, and determining an adapted channel estimate as a function of the channel estimate and the channel condition.

Abstract: A periodical signal is transmitted from a cellular base station. A memory circuit having a capacity of the signal for one cycle is provided. Newly received information is added to information previously accumulated in the memory circuit, and the resultant information is again accumulated in the memory circuit, thereby enabling the received information to be stored in the memory circuit having the capacity for only one cycle of the signal. Conventionally, a large amount of memory has been required to perform coherent adding for a long time period, whereas the present invention can reduce the circuit scale and the amount of memory, and also reduce the number of times of operations required for the long-period coherent adding, when a mobile station is located using a cellular communication system.

Abstract: An integrated wireless-global positioning system determines the location of a wireless terminal from satellite measurements and wireless network measurements. The accuracy of the location identified is dependent upon the quality of the measurement from the wireless network which, unfortunately, can contain measurement errors such as biases. Biases are caused by time delays which occur during the processing and transmission of signals. The time delays vary for each sector/base station and for each type of wireless terminal model being used. Calibration of these biases is important for the success of the integrated wireless global positioning system. For a small network system which has only a handful of base stations/wireless terminals, a specific system to calibrate the time delays for each base station and/or wireless terminal can be set up. The approach is, however, costly, time consuming, and subject to many errors.