Interdigital Technology Corporation

Intel Corporation

Gilbert E LaVean

D Ridgely Bolgiano

Duane R Bolgiano

A plurality of antennas transmit a first spread spectrum signal having an associated code. The first spread spectrum signal is received at the wireless user. For each received first spread spectrum signal, a second spread spectrum signal is transmitted having an associated code having a same phase as that received first spread spectrum signal. The second spread spectrum signals are received at the plurality of antennas. A distance measurement is determined between each antenna and the wireless user based on in part a received timing of the second signals. The wireless user's location is determined based on in part the distance determinations.

Method and apparatus for receiving code transmissions over timeslots and antennas

Locating a wireless user

A code is provided for transmission. The code is transmitted over a first antenna in a first time slot and the code is not transmitted over a second antenna in the first time slot. The code is transmitted over the second antenna in a second time slot and the code is not transmitted over the first antenna in the second time slot.

Code transmission over timeslots and antennas

Method and apparatus for locating a wireless user

An information signal is spread with a first spreading sequence producing a first spread signal for transmission over a first antenna. The information signal is spread with the first spreading sequence producing a second spread signal for transmission over a second antenna. The second antenna is not the first antenna. The relative position of the information signal and the first spreading sequence is different in the second spread signal than the first spread signal.

Transmitting an information signal over antennas

A transmitting station for communicating data in a cellular system utilizes transmission diversity by transmitting a plurality of signals. A transmitter is configured to transmit at least a first data signal corresponding to the data in a first time slot and to transmit a second data signal corresponding to the data in a second time slot. The second time slot occurs after the first time slot so that the first and second transmitted data signals are not simultaneously transmitted. Preferably, the transmitter includes a first antenna from which the first data signal is transmitted and a second antenna spaced apart from the first antenna from which the second data signal is transmitted. Where the transmitting station is for a CDMA system, the transmitter is configured to transmit said data signals as PN spread spectrum signals. In such case, an encoder is provided for spreading and modulating the data with PN codes to form the data signals. Preferably, different PN codes are used to form the data signals. In one embodiment, the PN codes are part of a PN code sequence produced by a PN code generator without resetting. The transmitting station may be a combined base station and transfer station.

Transmitting station for wireless telephone system with diversity transmission and method

A wireless communication system combines time and space diversity to reduce fading and simplify receiver design. In particular, a data packet which carries digital telephone traffic, is transmitted at three different times from three different antennas. The mobile subscriber receiver thus receives the same data packet at three different times from three different antennas, and uses the best data packet or combination of the data packets to reduce the effects of fading. A transfer station receives a time division multiplex multiple access (TDMA) signal from a base station carrying telephone data packet traffic to form three data packet repeats at spatially diverse antennas locations. The transfer station further modulates a code division multiple access (CDMA) system using a TDMA signal which links the mobile subscriber receiver to the transfer station. Each data packet received at the transfer station is thus retransmitted at three different times to the mobile subscriber station on a CDMA link. In one embodiment, each transfer station includes the three space diversity antennas. In a second embodiment, three transfer stations, each with one spatially diverse antenna is used. The time division and code division multiplex signals transmitted from space diversity antennas provide the ability to determine subscriber location using the same communication signals which are used for the primary telephone data communication. Specifically, the subscriber station receiver uses the absolute and relative time of arrival of the three repeated data packets to determine the respective distances of the mobile subscriber station to the three transmitting antennas. Since the transmitting antennas are at known fixed locations, receiver location is determined.

Wireless telephone system with diversity transmission and method

A transmitting station for communicating data in a CDMA cellular system that utilizes transmission diversity by transmitting a plurality of PN spread spectrum signals. The transmitting station spreads and modulates the data with a plurality of different PN codes to form a plurality of PN spread spectrum modulated data signals. A transmitter transmits the PN spread spectrum modulated data signals from the transmitting station. Preferably, the transmitter includes multiple spaced apart antennas from which the respective PN spread spectrum modulated data signals are transmitted. Preferably, the transmitter is configured to transmit the PN spread spectrum modulated data signals as a plurality of time slotted PN spread spectrum signals, each PN spread spectrum modulated data signal in a different time slot. In one embodiment, a PN code generator operates in conjunction with the forming the PN spread spectrum modulated data signals during different time intervals corresponding to the different time slots so that the PN codes used to spread the data are part of a PN code sequence produced by the PN code generator without resetting.

A subscriber station for a CDMA cellular system that utilizes transmission diversity by transmitting a plurality of PN spread spectrum signals. Data is transmitted as PN spread spectrum modulated data signals where at least a first PN spread spectrum modulated data signal is formed by spreading and modulating the data with a first PN code and a second PN spread spectrum modulated data signal is formed by spreading and modulating the data with a second PN code which is different than the first PN code. The subscriber station has a receiver which receives the first and second PN spread spectrum modulated data signals. A despreader and demodulator despreads and demodulates the received PN spread spectrum modulated data signal using the respective PN codes. A combiner reconstructs the data from the despread and demodulated data signals. The PN spread spectrum modulated data signals are preferably transmitted in different time slots so that the receiver is configured to receive the PN spread spectrum modulated data signals in the respective slots. Preferably, three PN spread spectrum modulated data signal are transmitted each from a different spaced apart antenna so that the subscriber station includes a measuring device for measuring respective times of arrival of the three data signals. A processor computes the location of the subscriber station from respective measured times of arrival of the data signals.

Receiving station for wireless telephone system with diversity transmission and method

A subscriber station for a cellular system that utilizes transmission diversity by transmitting a plurality time slotted signals for communicating data. A receiver sequentially receives at least a first data signal corresponding to the data in a first time slot and a second data signal corresponding to the data in a second time slot. The second time slot occurring after the first time slot so that the data signals are not simultaneously received. A combiner for reconstructs the data from the received data signals. Where the subscriber station is for a CDMA cellular system, the receiver receives the first and second time slotted data signals as PN spread spectrum modulated data signals. A despreader and demodulator despreads and demodulates the received data signals using PN codes and the combiner reconstructs the data from the despread and demodulated data signals. In one embodiment, first and second PN codes used by the receiver are part of a PN code sequence produced by a PN code generator without resetting. Preferably, the despreader and demodulater discriminate against all other PN spread spectrum modulated data signals. Preferably, the subscriber station includes a measuring device for measuring respective times of arrival of the received data signals and a processor for computing the location of the subscriber station from respective measured times of arrival of the data signals.

Transfer station for wireless telephone distribution system with time and space diversity transmission

A wireless communication system combines time and space diversity to reduce fading and simplify receiver design. In particular, a data packet which carries digital telephone traffic, is transmitted at three different times from three different antennas. The mobile subscriber receiver thus receives the same data packet at three different times from three different antennas, and uses the best data packet or combination of the data packets to reduce the effects of fading. A transfer station receives a time division multiplex multiple access (TDMA) signal from a base station carrying telephone data packet traffic to form three data packet repeats at spatially diverse antennas locations. The transfer station further modulates a code division multiple access (CDMA) system using a TDMA signal which links the mobile subscriber receiver to the transfer station. Each data packet received at the transfer station is thus retransmitted at three different times to the mobile subscriber station on a CDMA link.

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Reston, VA, United States of America

Gilbert E LaVean