Methods are disclosed for improving communications on feedback transmission channels, in which there is a possibility of bit errors. The basic solutions to counter those errors are: proper design of the CSI vector quantizer indexing (i.e., the bit representation of centroid indices) in order to minimize impact of index errors, use of error detection techniques to expurgate the erroneous indices and use of other methods to recover correct indices.

Techniques described herein provide phase and amplitude calibration of phased array antennas. In an N-by-M phased array having N*M channels, embodiments use aggregated measurements over multiple concurrently active channels to improve signal-to-leakage performance, while also using sequences of exclusion groups to yield an individualized calibration value for each channel (i.e., N*M individualized calibration values). For example, a J×K channel group of the array is selected in each of a sequence of measurement frames based on a calibration schema. Over J*K measurement sub-frames, a set of J*K aggregate measurements is obtained, each with different subsets of the channel group activated and excluded from the measurement. The aggregate calibration measurements can be used to compute J*K individualized calibration values, each for a channel of the channel group. In some implementations, each calibration value is computed as a complex value including both amplitude and phase calibrations information.

A method for correcting errors in a multiple antenna system based on a plurality of sub-carriers and a transmitting/receiving apparatus supporting the same are disclosed. The method includes determining a phase shift based precoding matrix phase shifted at a predetermined phase angle, initially transmitting each sub-carrier symbol to a receiver in a packet unit by using the phase shift based precoding matrix, reconstructing the phase shift based precoding matrix to reduce a spatial multiplexing rate if a negative reception acknowledgement (NACK) is received from the receiver, and retransmitting the initially transmitted sub-carrier symbol by using the reconstructed phase shift based precoding matrix or by changing the phase shift based precoding matrix using offset information fed back from the receiver or random offset information.

A transmission method for communication by a transmission apparatus of a wireless communication system performing wireless communication in a beamforming scheme is disclosed. The method may include assigning identifiers to all transmission beam directions in which transmission is possible and transmitting a reference signal with a beam identifier assigned in each direction, when identifier information of a beam direction, which allows reception from a reception apparatus, and error detection information are received, examining the error detection information to examine whether an error exists, and transmitting a response signal to the reception apparatus according to whether the examined error exists, and transmitting and receiving data on the basis of the received beam information when the error does not exist, as a result of the examination of the error detection information.

In this disclosure, methods for pre-compensation of the phase shifting error, and apparatuses for the same are disclosed. In one example, a device performs precoding of a digital signal, while acquiring information on an error caused by a phase shifting of the precoding. Then, the device performs phase compensation on the digital signal based on the acquired information. This phase compensated-digital signal is converted to an analog signal, and is transmitted to a receiver.

The invention relates to a human mobility measuring method comprising a structuring step where CDR raw metadata is filtered so as to identify a device identification, a cell site identification, a date, and a time; a data frame generating and sorting step where the filtered CDR metadata is sorted and the filtered sorted CDR metadata are projected into an occupancy grid comprising a location vs. time-bin matrix, a probabilistic map generating step of a device's location in space and time, and a filtering step to accurately represent human mobility from patterns that reflect errors, uncertainties, or patterns not related with real human mobility. The method further comprises a gap filling process allowing for a continuous localization of the device by extrapolating any trajectory in space and time of any device and a projecting step comprising projecting the trajectories defined at a Voronoi grid defined by the sites and towers to the road and street grid

Apparatus and methods for beamforming communication systems with sensor aided beam management are provided. In certain embodiments, a beamforming communication system includes an antenna array including a plurality of antenna elements. The beamforming communication system further includes a plurality of signal conditioning circuits operatively associated with the antenna elements, one or more sensors that generate sensor data, and a beam management circuit that controls the signal conditioning circuits to manage beamforming. The beam management circuit provides beam management based on the sensor data.

Apparatus and methods for beamforming communication systems with sensor aided beam management are provided. In certain embodiments, a beamforming communication system includes an antenna array including a plurality of antenna elements. The beamforming communication system further includes a plurality of signal conditioning circuits operatively associated with the antenna elements, one or more sensors that generate sensor data, and a beam management circuit that controls the signal conditioning circuits to manage beamforming. The beam management circuit provides beam management based on the sensor data.

Techniques described herein provide phase and amplitude calibration of phased array antennas. In an N-by-M phased array having N*M channels, embodiments use aggregated measurements over multiple concurrently active channels to improve signal-to-leakage performance, while also using sequences of exclusion groups to yield an individualized calibration value for each channel (i.e., N*M individualized calibration values). For example, a J×K channel group of the array is selected in each of a sequence of measurement frames based on a calibration schema. Over J*K measurement sub-frames, a set of J*K aggregate measurements is obtained, each with different subsets of the channel group activated and excluded from the measurement. The aggregate calibration measurements can be used to compute J*K individualized calibration values, each for a channel of the channel group. In some implementations, each calibration value is computed as a complex value including both amplitude and phase calibrations information.

Methods are disclosed for improving communications on feedback transmission channels, in which there is a possibility of bit errors. The basic solutions to counter those errors are: proper design of the CSI vector quantizer indexing (i.e., the bit representation of centroid indices) in order to minimize impact of index errors, use of error detection techniques to expurgate the erroneous indices and use of other methods to recover correct indices.