National Instruments Corporation

Telefonaktiebolaget Lm Ericsson (publ)

Vodafone Holding Gmbh

Eckhard Ohlmer

Michael Löhning

James Wesley McCoy

Gerhard P Fettweis

Ahsan Aziz

Udo Wachsmann

Yong Rao

Stefan Krone

Michael Lentmaier

Jörg Hofrichter

Nicola Michailow

In a wireless transceiver station having M antennas, designate an antenna as a target reference antenna (TRA) and for each antenna m other than the TRA: define N distinct paths from antenna m to TRA through zero or more intermediate reference antennas, N is two or more, each distinct paths has a distinct associated set of one or more antenna pairs; for each antenna pair of the sets, estimate an effective forward and backward channel response by sending calibration pilots forth and back between the antenna pair and calculate a reciprocity coefficient for the antenna pair using the estimated channel responses; for each of the N distinct paths, calculate a reciprocity coefficient estimate using the reciprocity coefficients calculated for the set of antenna pairs associated with the path; and combine the N calculated reciprocity coefficient estimates to produce a final reciprocity coefficient estimate for antenna pair (m, target reference antenna).

Wireless transceiver station with performs multi-path reciprocity calibration with multiple reference antennas

A pre-equalization phase tracking unit, for each signal block of received series: computes autocorrelation between portion of identical-as-transmitted initial and terminal sequences and computes phase of autocorrelation; estimates start phase of block processing window using autocorrelation phase and start phase of previous signal block in series; estimates phase drift within window by interpolating using estimated start phases of at least the signal block and next signal block in series; and computes phase compensation signal using estimated phase drift. A post-equalization phase tracking unit subdivides the block into time sequence of groups of equalized symbols. For each group: compute de-rotated version of each symbol using previous group's accumulated phase to blindly estimate residual group phase; assign group's accumulated phase with sum of group's residual phase and previous group's accumulated phase; estimate phase drift within group by using at least group's accumulated phase to compute phase compensation signal.

Wireless radio receiver that performs adaptive phase tracking

A post-equalization phase tracking unit, for each signal block of a received series: computes beginning absolute phase rotation using equalized preceding pilot symbols; subdivides the block into a time sequence of groups of equalized symbols; initializes accumulated phase associated with the first-in-time group with the absolute phase rotation. For each group, the unit: computes a de-rotated version of each symbol using the previous group's accumulated phase used to blindly estimate a residual group phase; assigns the group's accumulated phase with a sum of the group's residual phase and the previous group's accumulated phase; estimates phase drift within the group by using at least the group's accumulated phase to compute a phase compensation signal. A pre-equalization phase tracking unit computes a phase of autocorrelation between identical-as-transmitted initial/terminal sequence portions; estimates a start phase using the autocorrelation phase and the previous signal block start phase; interpolates start phases to estimate phase drift.

A flexible real-time scheduler for a wireless communication node, enabling the node to communicate with a remote node using dynamically variable frame structure. The scheduler continuously receives map information defining the frame structure of frames in a frame sequence. Each frame includes a plurality of slots (e.g., time slots or frequency slots). The map information specifies for each slot of each frame whether the slot is to be a transmit slot or a receive slot. The scheduler drives a transmitter to transmit during the slots assigned for transmission, and drives a receiver to receive during the slots assigned for reception. (The number of slots per frame and the size of each slot are also configurable.)

Flexible real time scheduler for time division duplexing and/or frequency division duplexing

A method and corresponding devices for processing and transmitting information are described. A sequence of binary signals is mapped to symbols that forms a two-dimensional matrix of symbols in one of the frequency-time or time-time or time-frequency or frequency-frequency domain and which may be filtered in that domain. Selecting the diagonal elements of said matrix forms a transmit vector.

Method and transmitter/receiver for data transmission with flexible exploitation of time and frequency diversity

A technique for precoding a signal to be transmitted over a physical channel from a sender to a receiver is provided. A method includes receiving precoding information and applying precoding matrix at the sender based on the precoding information. The precoding information is received via a feedback mechanism from the receiver. The application of the precoding matrix results in a precoded signal for transmission over the physical channel. The precoding matrix enhances mutual information at the receiver.

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Dresden, Germany

Eckhard Ohlmer