A multi-mode receiver includes a channel decomposition module (e.g., a Rake receiver) for separating a received signal into multipath components, an interference selector for selecting interfering paths and subchannels, a synthesizer for synthesizing interference signals from selected sub channel symbol estimates, and an interference canceller for cancelling selected interference in the received signal. At least one of the channel decomposition module, the synthesizer, and the interference canceller are configurable for processing multi-mode signals.

A method and an apparatus determine a precoding matrix indicator user equipment and a base station. The method includes: determining a precoding matrix indicator PMI where the PMI corresponds to a precoding matrix W, and the precoding matrix W satisfies a first condition, a second condition or a third condition; and sending the PMI to a base station. Embodiments of the present invention further provide a corresponding apparatus, and the corresponding user equipment and base station. Technical solutions provided in the embodiments of the present invention can effectively control a beam, especially a beam shape and a beam orientation, in a horizontal direction and a perpendicular direction.

Generating signals from non-GNSS transmitters, and processing the signals using a GNSS positioning module. Systems and methods identify a chipping rate, identify a PN code length, generate a PN code that has a length equal to the identified PN code length, generate a positioning signal using the identified chipping rate and the generated PN code, and transmit the positioning signal from the transmitter. The PN code length may produce, at the identified chipping rate, a PN code duration that is equal to or is a multiple of a PN code duration used in a GNSS system, the identified chipping rate may be equal to or a multiple of a chipping rate used in a GNSS system, and the identified PN code length may be equal to or a multiple of a PN code length used in a GNSS system.

A receiver includes a first finger that receives a non-interference-cancelled signal and output first demodulated data, a first phase estimate, and a first PN code. The receiver also includes a second finger that selectively receives the non-interference-cancelled signal and a first interference-cancelled signal generated from the non-interference-cancelled signal based on the first phase estimate and the first PN code. The second finger also outputs second demodulated data.

An apparatus and method for use with a shared access communication channel is disclosed. A wireless network device receives signals and recovers data from a first plurality of subscriber units and a second plurality of subscriber units in a time interval. Received signals from the first plurality of subscriber units are distinguishable by having unique pseudo noise (PN) sequence with respect to others of the first plurality of subscriber units. Received signals the second plurality of subscriber units are distinguishable by a unique orthogonal sequence with respect to others of the second plurality of subscriber units. Received signals are distinguished between the first and second plurality of subscriber units based on detection of an orthogonal sequence present only in the received signals from the second plurality of subscriber units.

A system for communicating radio-frequency (RF) signals includes a receiver subsystem that employs a phased antenna array, and signal spreading of the respective responses of the elements of the phased antenna array. The codes used for spreading are unique to each antenna element. The spread signals are combined and analog-to-digital conversion (ADC) is applied to the combined spread signal. The signals to be spread may be grouped according to a signal characteristic such as signal polarization or whether the signal is an in-phase or quadrature signal. A respective signal combiner and a respective ADC may be used for each group. The communication system may include a transmission subsystem that employs signal de-spreading that is unique for each antennal element.

The present invention provides systems and methods for parallel interference suppression. In one embodiment of the invention, a processing engine is used to substantially cancel a plurality of interfering signals within a received signal. The processing engine includes a plurality of matrix generators that are used to generate matrices, each matrix comprising elements of a unique interfering signal selected for cancellation. The processing engine also includes one or more processors that use the matrices to generate cancellation operators. A plurality of applicators applies the cancellation operators to parallel but not necessarily unique input signals to substantially cancel the interfering signals from the input signals. These input signals may include received signals, interference cancelled signals and/or PN codes.

A method for correlating using an N-dimensional accumulator to test 2.sup.N alignments. The method comprises transmitting a spread code comprising a data sequence and a pseudo-noise sequence; receiving, at a plurality of successive clock cycles, the spread code further comprising a plurality of alignments; assigning each of the plurality of alignments to an alignment vector comprising N dimensions; generating a binary representation of each of the plurality of alignments in the alignment vector, wherein 1 and 1 to depict the logic states 0 and 1 with the DS-CDMA signal that has been received by the receiver; accumulating a plurality of moving averages for each dimension of the N-dimensional alignment vector; determining an absolute value of each moving average; combining each of the plurality of moving averages with each corresponding alignment vectors; identifying when the sign of each dimension of the accumulation vector becomes stable; and determining the alignment vector.

A method for correlating using an N-dimensional accumulator to test 2.sup.N alignments. The method comprises transmitting a spread code comprising a data sequence and a pseudo-noise sequence; receiving, at a plurality of successive clock cycles, the spread code further comprising a plurality of alignments; assigning each of the plurality of alignments to an alignment vector comprising N dimensions; generating a binary representation of each of the plurality of alignments in the alignment vector, wherein 1 and 1 to depict the logic states 0 and 1 with the DS-CDMA signal that has been received by the receiver; accumulating a plurality of moving averages for each dimension of the N-dimensional alignment vector; determining an absolute value of each moving average; combining each of the plurality of moving averages with each corresponding alignment vectors; identifying when the sign of each dimension of the accumulation vector becomes stable; and determining the alignment vector.

The present disclosure provides a method and a system to estimate LO leakage and quadrature error parameters for a transmitter RF front end, such as a direct up-conversion transmitter RF front end, in a joint fashion. The proposed method utilizes a PN sequence inserted at the transmitter baseband. At the observation receiver side, an RX accumulator is implemented to sum receiver signals to take advantage of a despreading gain using the same PN sequence from transmitter side. Through the despreading process, the receiver-transmitter channel may be estimated and used to extract the quadrature error parameters. The estimated channel may also be used to eliminate user data interference presented within the RX accumulator output, which may further be used to compute the LO leakage.