Analysis and design of an interference canceller for collocated radios

Abstract

Abstract-An active interference cancellation scheme is presented to mitigate interference between Bluetooth and wireless local area network (IEEE 802.11 b) radios operating in close proximity. This method is extensible to other mutually interfering radio devices. A reference signal correlated to the original interferer is used to generate a cancellation signal by means of amplitude and phase alignment, and filtration. The filter employed emulates the coupling channel responsible for interference. An implementation of this procedure in 0.18-m Si-complementary metal-oxide-semiconductor (CMOS) integrated-circuit (IC) technology is also presented. The circuits fabricated are tunable and are controlled by a closed-loop adaptive process including an error minimization method. The cancellation system designed achieves 15-30 dB of interference suppression for different cases. A total power of 14 mW is dissipated by the CMOS ICs designed.

Full-duplex wireless communications using off-the-shelf radios: Feasibility and first results

“…Work in [4,5] shows characterization of self-interference cancellation mechanisms for scenarios similar to the ones we have considered. However, although work in [4,5] reports the amount of self-interference cancellation that can be achieved by their proposed system, they do not report if the resulting full-duplex system can achieve better performance than a halfduplex system.…”

“…However, although work in [4,5] reports the amount of self-interference cancellation that can be achieved by their proposed system, they do not report if the resulting full-duplex system can achieve better performance than a halfduplex system. We provide comparison of achievable rates of full-duplex and half-duplex systems for all the self-interference cancellation mechanisms that we have considered.…”

Full-duplex amplify-and-forward relays with optimized transmission power under imperfect transceiver electronics

“…This coupling is significant, because transmitter and receiver antennas are typically close to each other in a FD device, or transmitter and receiver chains may even share the same antenna array. The effect of antenna and RF cancellation stages is to reduce the magnitude of the main path of the SI channel [1,9,11]. We assume that the The proposed widely linear I/Q compensation and SI cancellation scheme consists of a pair of filters:…”

“…In compact transceivers, the interference level is usually high compared to the signal of interest [8], depending on the transmitted signal power, the isolation between transmitter and receiver antennas, and the surrounding environmental reflectors. Self-interference is mitigated by a combination of passive and active antenna cancellation [9,10] and RF cancelers [11,12], both in the analog domain; and a digital cancellation [13][14][15][16]. Antenna cancellation techniques aim to reduce the physical coupling between the transmitter and the receiver antennas.…”

Full-Duplex Bidirectional MIMO: Achievable Rates Under Limited Dynamic Range

“…Digital-domain suppression attempts to mitigate self-interference after analog-to-digital conversion (ADC) and will not be effective if the analog circuitry and/or ADCs are already overwhelmed by self-interference. Analog-domain suppression attempts to mitigate self-interference between the receiver's antenna(s) and ADC(s); this method was used early on (e.g., [10]) and continues to be the focus of many recent works (e.g., [2], [5], [9], [11], and [12]). Propagation-domain suppression attempts to mitigate self-interference in the wireless propagation environment, before it has a chance to overwhelm the analog and digital circuitry.…”