Transmitter Linearization by Beamforming

Transmitter Linearization for Portable Wireless Communication Systems

Linearization technique using digital Cartesian loop transmitter

The study of a Digital Cartesian loop transmitter as power amplifier linearization technique is presented. It is based on Cartesian loop architecture but introducing the advantages and possibilities of using digital solutions. Stability is assured by including some adjustment elements in the loop and the digital implementation avoids modulator and demodulator impairments and provides an accurat...

Linearization Transmitter Using Asynchronous Sigma Delta Modulation for UMTS Handsets

 It is crucial for the spectral-efficient communication systems, associated with the sophisticated digital modulation formats to be able to handle the RF signal containing a probably very large variation of the envelope magnitude. The aim of this work is to build an optimal transmitter linearization architecture suitable to achieve a highly linear transmission and to be highly power efficient....

Transmitter and Precoding Order Optimization for Nonlinear Downlink Beamforming

The downlink of a multiple-input multiple output (MIMO) broadcast channel (BC) is considered, where each receiver is equipped with a single antenna and the transmitter performs nonlinear Dirty-Paper Coding (DPC). We present an efficient algorithm that finds the optimum transmit filters and power allocation as well as the optimum precoding order(s) possibly affording time-sharing between individ...

Robust Beamforming in Interference Channels with Imperfect Transmitter Channel Information

We consider K links operating concurrently in the same spectral band. Each transmitter has multiple antennas, while each receiver uses a single antenna. This setting corresponds to the multiple-input single-output interference channel. We assume perfect channel state information at the receivers whereas the transmitters only have estimates of the true channels. The channel estimation errors are...