Telefonaktiebolaget Lm Ericsson (publ)

Tomas Andersson

Miguel Lopez

Benny Lennartson

Dennis Hui

Leonard Rexberg

Göran Nilsson

Anders Martinsson

Gustav Almqvist

Pär Holmgren

Systems and methods for linearizing a radio system are disclosed. In some embodiments, a radio system comprises an antenna array, transmit branches comprising respective power amplifiers, a predistortion subsystem comprising predistorters for the transmit branches respectively, a receive antenna element, a transmit observation receiver having an input coupled to the receive antenna element, and an adaptor. The predistorters predistort respective transmit signals to provide predistorted transmit signals to the respective transmit branches for transmission via respective active antenna elements in the antenna array. The transmit observation receiver is operable to receive, via the receive antenna element, a combined receive signal due to coupling between the receive antenna element and the active antenna elements. The adaptor is operable to generate a combined reference signal based on the transmit signals and configure predistortion parameters input to the predistorters based on the combined reference signal and the combined receive signal.

Active array antenna linearization

In a radio system node, such as a Base Transceiver Station (BTS), a compensation unit is provided to convert information about downlink signal strength in a measurement report received from a mobile station when the signal to the mobile station is transmitted using several co-channel signals transmitted simultaneously in the same time slot and at the same frequency.

Report mechanism in a radio system reusing one time-slot

A receiver is provided that is configured to estimate the symbol constellation of a signal modulated using a quaternary symbol constellation where data is transmitted to two mobile stations multiplexed on a shared channel comprising two branches, where the branches correspond to the real and imaginary parts of one complex-valued baseband signal. The receiver is configured to demodulate the modulated signal using the training sequences from both sub-channels.

Receiver for MUROS adapted to estimate symbol constellation using training sequences from two sub-channels

In a method and a transmitter data is transmitted to two mobile stations sharing the same frequency band and the same timeslot. The data is modulated using a quaternary symbol constellation. Further, the data is transmitted to two mobile stations multiplexed on a shared channel comprising two branches and the transmission power for the transmitted data is set in response to the relative gain of the two branches. Hereby, the total system interference is reduced. The method and transmitter further allows for a cellular radio system individual power control loops for the two sub-channels when the system uses MUROS.

Method of power control

In a method of enabling model order selection for joint channel synchronization and noise covariance estimation of at least one received signal in a wireless communication network, generating Sa spatially and temporally stacked signal model by stacking successive samples of temporally adjacent received signal vectors and corresponding training vectors, computing Sa noise variance matrix for each hypothesized synchronization position, channel length and stacking order, based on the stacked training symbols: determining Sa best synchronization position for the received signal, based on the stacked training vectors, by jointly determining the best synchronization position for the received signal and estimating a channel length and a stacking order for said signal model based on the stacked training vectors.

Growing community of inventors

Vasteras, Sweden

Tomas Andersson