Abstract: Disclosed is a method for detecting a spoofing source in satellite communications, the method comprising using a PAA to form beams corresponding to incoming signals originating from a plurality of signal sources. The PAA identifies positions of the plurality of signal sources. Next, almanac positions of known satellites in a constellation of satellites are compared with positions of the plurality of signal sources to match the plurality of signal sources with the known satellites. Thereafter, each unmatched signal source in the plurality of signal sources is designated as a spoofing source. In one implementation, a spoofing signal is used as a signal of opportunity by calculating and communicating corrected position and time information to users that receive the spoofing signal.

Abstract: A wireless transmit/receive unit (WTRU) is described. The WTRU includes a front-end unit (FEU), a signal processing unit (SPU), and a resource management unit (RMU). The FEU receives a radio frequency (RF) signal, generates time-interleaved samples, an includes: a first array of first time-interleaved samplers, a second array of second time-interleaved samplers, and a third array of third time-interleaved samplers. The SPU receives and combines the plurality of time-interleaved samples and generates a signal quality measurement and in-phase and quadrature-phase (IQ) complex samples. The RMU receives the signal quality measurement and allocates FEU resources in conjunction with a front-end unit controller (FEUC) based on the signal quality measurement. The FEUC generates control signals based on the received signal quality measurement from the RMU.

Abstract: A system for balancing a signal having I and Q components includes means for cross correlating the I and Q components to produce a cross correlation product; means for adjusting the gain of each I and Q signal component in accordance with said cross correlation product; and means for adding one component with the adjustable gain of the other component to produce a phase-balanced signal.

Abstract: A wireless transmit/receive unit (WTRU) is described. The WTRU includes a front-end unit (FEU), a signal processing unit (SPU), and a resource management unit (RMU). The FEU receives a radio frequency (RF) signal, generates time-interleaved samples, an includes: a first array of first time-interleaved samplers, a second array of second time-interleaved samplers, and a third array of third time-interleaved samplers. The SPU receives and combines the plurality of time-interleaved samples and generates a signal quality measurement and in-phase and quadrature-phase (IQ) complex samples. The RMU receives the signal quality measurement and allocates FEU resources in conjunction with a front-end unit controller (FEUC) based on the signal quality measurement. The FEUC generates control signals based on the received signal quality measurement from the RMU.

Abstract: The number of users and data capacity of wireless systems are increased by employing apparatus and method for increasing the number of spreading codes available in the system by providing a mechanism to reuse the already allocated spreading code or use the codes that may correlate to those already being used within the same sector/cell. This, in return, provides capacity improvement proportional to the number of added base station (BS) antennas for each cell. An antenna null steering technique for code allocation maintains the cross correlation properties of the codes only for the desired user and to obtain a gain in capacity improvement.

Abstract: A method and apparatus for dynamic resource allocation of an RF sampling system based on a signal quality measurement determined by generating a plurality of time-interleaved samples from a received radio frequency (RF) signal and combining the plurality of time-interleaved samples to generate the signal quality.

Abstract: The number of users and data capacity of wireless systems are increased by employing apparatus and method for increasing the number of spreading codes available in the system by providing a mechanism to reuse the already allocated spreading code or use the codes that may correlate to those already being used within the same sector/cell. This, in return, provides capacity improvement proportional to the number of added base station (BS) antennas for each cell. An antenna null steering technique for code allocation maintains the cross correlation properties of the codes only for the desired user and to obtain a gain in capacity improvement.

Abstract: The number of users and data capacity of wireless systems are increased by employing apparatus and method for increasing the number of spreading codes available in the system by providing a mechanism to reuse the already allocated spreading code or use the codes that may correlate to those already being used within the same sector/cell. This, in return, provides capacity improvement proportional to the number of added base station (BS) antennas for each cell. An antenna null steering technique for code allocation maintains the cross correlation properties of the codes only for the desired user and to obtain a gain in capacity improvement.

Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.

Abstract: A multi-mode wireless transmit/receive unit (WTRU) includes at least one antenna, first and second communication mode receivers and a first communication mode transmitter. The first and second receivers simultaneously receive signals from the antenna. The first transmitter generates and sends a first type of signal to the antenna while, at the same time, the second receiver receives a second type of signal from the antenna. In a preferred embodiment, the WTRU further includes a vector multiplier configured to reduce or eliminate interference of signals received by the second receiver, the interference being caused by the first transmitter. The vector multiplier adjusts the phase and amplitude of noise (i.e., spurious in-band noise) measured by the second receiver. The WTRU may further include a second communication mode transmitter configured to generate and send a second type of signal to the antenna.

Abstract: A self-interference canceller (SIC) is incorporated into a transceiver to reduce or eliminate modem jamming when a transmitter in the transceiver transmits at high power levels. The SIC is configured to receive at a first input a transmitter noise reference signal including a self-interfering signal component generated by the transmitter, to receive at a second input a corrupted signal including the self-interfering signal component and a desired signal component generated by the transmitter, and to output a correction signal that resembles the self-interfering signal component. The correction signal is subtracted from the corrupted signal to generate a processed signal that is input to the modem. The SIC may be disabled when the output power of the transmitter is at a level below a predetermined threshold. The invention may be applied to a multi-radio access technology (RAT) transceiver.

Abstract: In a digital Cartesian modulation transmitter, an encoder generates 1-bit logic signals from in-phase and quadrature signals. A single bit digital modulator multiplexes the 1-bit logic signals for Cartesian I/Q modulation. A digital upconverter (DUC) upconverts the multiplexed 1-bit logic signal. A digital power amplifier (DPA) generates a radio frequency (RF) signal based on the upconverted signal. In a digital polar modulation transmitter, an encoder converts a magnitude signal to a first 1-bit logic signal. A digital phase modulator modulates a carrier using a phase signal to generate a second 1-bit logic signal. A DUC upconverts the second 1-bit logic signal. A first-in first-out (FIFO) memory stores the first 1-bit logic signal. A combiner combines angle information contained in the second 1-bit logic signal with magnitude information contained in the first 1-bit logic signal stored in the FIFO memory. A DPA generates an RF signal based on the combined signal.

Abstract: A method and apparatus for dynamic resource allocation of an RF sampling system based on a signal quality measurement determined by generating a plurality of time-interleaved samples from a received radio frequency (RF) signal and combining the plurality of time-interleaved samples to generate the signal quality.

Abstract: In order to compensate for performance degradation caused by inferior low-cost analog radio component tolerances of an analog radio, a wireless communication transmitter employs a control process to implement numerous digital signal processing (DSP) techniques to compensate for deficiencies of such analog components so that modern specifications may be relaxed. By monitoring a plurality of parameters associated with the analog radio, such as temperature, bias current or the like, enhanced phase and amplitude compensation, as well as many other radio frequency (RF) parameters may be implemented.

Abstract: A format converter for use with a universal mobile telecommunications system (UMTS) having a transceiver, a wireless local area network (WLAN) having an access point (AP) and a wireless terminal, for providing access to the UMTS by the terminal. The format converter comprises a WLAN transceiver for sending and receiving messages to and from the AP; a UMTS transceiver for sending and receiving messages to and from the transceiver in the UMTS; and a translator for translating WLAN messages to UMTS format and UMTS messages to WLAN format.

Abstract: A method and system for determining amplitude and phase compensation values used to adjust the amplitude and phase characteristics of real and imaginary signal components of complex signals processed by an analog radio transmitter. The compensation values may be determined in response to detecting a significant temperature change in the transmitter. Corresponding amplitude and phase adjustment signals having levels that correspond to the compensation values are provided to respective amplitude and phase imbalance compensation modules to adjust the amplitude and phase characteristics of at least one of the real and imaginary signal components.

Abstract: An automatic gain control system prevents input overload by precisely controlling the input level of a received, digitally modulated signal without variable gain amplification. Limiting amplification in conjunction with a logarithmic detection splits an input signal path in two, providing separate phase and amplitude information for downstream digital signal processing, where the separate phase and amplitude information is processed without variable gain artifacts. The separated phase information may further be divided into I and Q signals.

Abstract: Method and apparatus for transfer of signals from multiple antennas down to baseband over a common radio frequency (RF) chain. Antenna selection having greater flexibility and applicability to both uplink and downlink is obtained by giving priority to the antenna receiving a better/best quality signal. Measurements are taken by at least a channel estimator during each time slot to determine the weighting to be given to the antenna with the better/best quality signal. Techniques and apparatus are provided to take measurements over a range of intervals from time slots to single symbols, for example, to select the best signal. The techniques described herein may be used individually, and in some cases are combined to receive additional benefits in efficiency. For example, one or more of recent and/or current channel estimation, history, optimization may be employed, in addition to channel estimation, to determine signal quality.

Abstract: A wireless transmit/receive unit (WTRU) uses an oscillator providing accuracy for synchronized communications parameters in an active mode, and operates at reduced power during a discontinuous reception (DRX) mode. A real time clock (RTC) is used as the frequency standard during the reduced power operation, and a frequency adjustment is effected while the RTC is used as the frequency standard. By effecting the frequency adjustment, the RTC is able to be used as the frequency standard for substantial time periods, thereby reducing power consumption of the WTRU during the DRX mode.

Abstract: The present invention provides a base station architecture that is modular in configuration, lowering the initial cost of implementing a new CDMA telecommunication system for a defined geographical region while allowing for future capacity. The scalable architecture is assembled from a digital base station unit that is configured to support a plurality of simultaneous wireless calls connecting to a conventional public switched telephone network. For initial startup, two base station units are deployed for redundancy in case of a single failure. Additional base station units may be added when the need arises for extra traffic capacity. If sectorization is required, the base station units may be directionally oriented. Coupled to and remote from each base station unit are two amplified antenna modules that contain an omni-directional or an external directional antenna, a high power RF amplifier for transmitted frequencies and a low noise amplifier for received frequencies.