Joint analog and digital self-interference cancellation and full-duplex system performance

2020

J Wireless Com Network

Self Cite

In the in-band full-duplex(FD) systems, the self-interference (SI) power can be more than 100 dB higher than the power of the received data signal. In order to enable the FD transmission, several SI cancelation stages are needed in a FD transceiver. By combining the cancelation at the radio frequency (RF) with a specially designed antenna and cancelation circuitry and SI cancelation at the digital baseband, the required level of SI cancelation can be achieved even with a non-linear power amplifier. In this paper, a FD transceiver architecture is modeled with simulation tools that allow to use realistic antenna and analog transceiver models and at the same time enable algorithm studies. The analog SI cancelation at the RF is controlled by the baseband digital processing unit, and the tuning of the RF canceler is performed with an automatic gain control enhanced iterative algorithm. The combined cancelation performance of the antenna and RF canceler varies between 62 and 82 dB depending on the studied cases. The digital baseband SI cancelation is based on the Hammerstein model in order to take the power amplifier non-linearity into account. The coefficients of the Hammerstein model are estimated with a self-orthogonalizing adaptive algorithm. When realistic phase noise and IQ imbalance values are taken into account, the SI after all the cancelation stages can decrease the signal-to-interference-and-noise-ratio (SINR) by few decibels (dB). In order to further enhance the SI cancelation, the Hammerstein based SI canceler is extended to cancel also the effect of the receiver IQ imbalance. With the extended baseband canceler, the cancelation performance is mainly limited by the phase noise

Section: Si Cancelationmentioning

confidence: 99%

Self-interference cancelation in the presence of non-linear power amplifier and receiver IQ imbalance

2020

J Wireless Com Network

Self Cite

“…Antenna design is based on the characteristic modes theory [12], [13]. The same antenna model was used also in [14], [15]. The RF canceller is is shown in Fig.…”

Section: Transceiver and Self-interference Cancellationmentioning

confidence: 99%

Analog Self-Interference Cancellation with Automatic Gain Control for Full-Duplex Transceivers

2018 IEEE 87th Vehicular Technology Conference (VTC Spring)

2018

Self Cite

The main challenge in full-duplex transceiver design is the self-interference (SI). Analog SI isolation is performed at radio frequency (RF) by using an antenna design based on the characteristic modes theory and using active cancelation principle. Two different structures based on using a vector downconverter and a complex multiplier are used for analog baseband SI cancellation. Cancellers are tuned using a automatic gain control (AGC) enhanced variable-step steepest descent algorithm while transmitting a data signal to a distant node in half-duplex mode. Simulations show that the inclusion of AGC into the tuning process speeds up the convergence significantly.

“…Antenna design is based on the characteristic modes theory [13], [14]. The same antenna model was used also in [9], [15], [16]. The RF canceler is shown in Fig.…”

Section: Transceiver and Self-interferencementioning

confidence: 99%

Performance of a Full-Duplex System in Non-Linear and Time-Varying Self-Interference Channel

2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

2018

Self Cite

The main challenge in full-duplex transceiver design is the self-interference (SI). Analog SI isolation is performed at radio frequency (RF) signal by using an antenna design based on the characteristic modes theory and using active cancelation processing. The RF canceler is tuned using an automatic gain control (AGC) enhanced variable-step steepest descent algorithm while transmitting a data signal. The inclusion of a non-linear power amplifier does not affect the tuning performance, when realistic adjacent channel power ratio cases are considered. However, the changes in the SI channel can have a major impact on the full-duplex link due to need to re-tune the canceler repeatedly. Index terms-Full-duplex, self-interference, link capacity, non-linearity