A receiving apparatus for SNR estimation of a signal such as the LTE PUCCH, transmitted over a channel of an OFDM wireless communication system. The proposed apparatus brings determines the noise power level in the frequency domain based on a noise covariance matrix where timing errors are back compensated in the equation since timing error is expressed a complex exponential therein. Contrary to the common methods used for determining the noise power level, in the present invention deriving the channel estimate components from the pilot symbol(s) comprised in the received signal is not required. Based on the present invention, user's transmit power is reduced thereby improving battery power longevity. Further, since interference is reduced, more users may be multiplexed together in the same resources. A method and a computer program product are also claimed.

Various embodiments of the invention are directed to methods and systems for high capacity OFDM transmitters and receivers. For example, various embodiments of the transmitter may utilize an architecture comprised of a multiplicity of baseband processing subsystems for receiving and modulating user input data from the respective groups of users, a subsystem for the generation of an OFDM signal comprised of a multiplicity of OFDM signals with spectrum sharing, and a baseband to RF conversion subsystem. Various embodiments of the receiver may utilize an architecture comprised of a multicarrier demodulator, a vector splitter, an inverse transform unit, and an interference mitigating symbol detection subsystem.

A MIMO demodulating apparatus includes: a phase difference corrector that compensates for a phase shift by utilizing the phase difference between received signals to output phase corrected signals; an interference compensator that receives the phase corrected signals as input and, by means of adaptive control, performs elimination of interference and separation and extraction of a desired signal; a phase noise compensator to compensate for phase error remaining in the desired signal; a signal determiner that determines transmitted data from the output signal of the phase noise compensator to output the transmitted data and outputs an error signal; and an error signal phase rotator that subjects the error signal to a phase rotating process in accordance with the phase error compensation amount to perform adaptive control.

A method of an RFC chip for a station, the RFC chip including a WLAN communication module to decode a DL MU-MIMO wireless signal, the method including: determining an FS layer column based on a product of a channel matrix of the station and an estimate of a steering matrix of the station; ordering columns of a sub-matrix of an effective channel matrix of the station to determine one or more SS layer columns from the sub-matrix, the sub-matrix being determined by removing, from the effective channel matrix, a column corresponding to the determined FS layer column; configuring a modified effective channel matrix based on the determined FS layer column and the ordered columns of the sub-matrix, the determined FS layer column being determined as an FS layer column of the modified effective channel matrix; and determining a symbol of the station based on the modified effective channel matrix.

A method of performing uplink channel estimation and a base station using the same are provided. The method is applicable to serve at least two UE equipments (UEs) in a communication system. The at least two UEs are located in at least two beam sectors respectively. The base station comprises a plurality of antennas. The method includes: determining whether multipath of the at least two UEs passing through a same beam sector; assigning a first and a second training sequence for a first UE and a second UE of the at least two UEs respectively; receiving a reference signal, wherein the reference signal is transmitted by the first UE and the second UE according to the first and the second training sequence; and performing channel estimation for the first UE and the second UE according to the reference signal, the first and the second training sequence.

A system for cancelling interference in a wireless network, the system comprising apparatus for computing and outputting at least N weighting vectors; and apparatus for cancelling interference from antennae outputs received by the system using the weighting vectors respectively by converting the weighting vectors into FIR filter coefficients and applying FIR filters corresponding to the FIR filter coefficients to derivatives of antennae outputs received by the system. The apparatus for computing and outputting weighting vectors may be operative by estimating a spatial signature while distinguishing interference spatial signature from desired signal spatial signature although both are received simultaneously.

An apparatus for switching between receivers according to a characteristic of a received signal in a communication system includes a radio frequency unit that modulates at least two signals received from transmission devices, and a Channel Impulse Response (CIR) shape comparison unit that determines characteristics of the modulated signals by using a CIR and selects a receiver according to the determined characteristics of the modulated signals.

A system for cancelling interference in a wireless network, the system comprising apparatus for computing and outputting at least N weighting vectors; and apparatus for cancelling interference from antennae outputs received by the system using the weighting vectors respectively by converting the weighting vectors into FIR filter coefficients and applying FIR filters corresponding to the FIR filter coefficients to derivatives of antennae outputs received by the system. The apparatus for computing and outputting weighting vectors may be operative by estimating a spatial signature while distinguishing interference spatial signature from desired signal spatial signature although both are received simultaneously.

A flexible time-frequency grid is proposed. A baseline OFDM format consisting of CP and a following symbol interval is scaled in time to generate a set of extended OFDM frame formats. The set of extended OFDM frame formats is further extended by scaling in bandwidth. The OFDM frame formats and the extended OFDM frame format set are used dynamically in the wireless communication system in accordance to the changes of the communication environment. Furthermore, various methods are proposed to avoid and/or combat performance degradation of the resource elements (REs) interfered by non-orthogonal REs in the neighborhood due to different OFDM symbol configurations in the flexible time-frequency grid.

A method and devices are provided. The method includes transmitting, by a first base station, a superposition of a codeword of first information and a codeword of second information to N terminals, where the first information and the second information correspond to each terminal of the N terminals, and N is a positive integer; and a codeword of first information corresponding to the r.sup.th terminal is obtained according to a transmit rate and a transmit power for the codeword of the first information corresponding to the r.sup.th terminal, a codeword of second information corresponding to the r.sup.th terminal is obtained according to a transmit rate and a transmit power for the codeword of the second information corresponding to the r.sup.th terminal, the transmit rate for the codeword of the first information corresponding to the r.sup.th terminal meets a first condition.