Showing papers by "Aarno Parssinen published in 2014"

Analog/RF Solutions Enabling Compact Full-Duplex Radios

Abstract: In-band full-duplex sets challenging requirements for wireless communication radios, in particular their capability to prevent receiver sensitivity degradation due to self-interference (transmit signals leaking into its own receiver). Previously published self-interference rejection designs require bulky components and/or antenna structures. This paper addresses this form-factor issue. First, compact radio transceiver feasibility bottlenecks are identified analytically, and tradeoff equations in function of link budget parameters are presented. These derivations indicate that the main bottlenecks can be resolved by increasing the isolation in analog/RF. Therefore, two design ideas are proposed, which provide attractive analog/RF-isolation and allow integration in compact radios. The first design proposal targets compact radio devices, such as small-cell base stations and tablet computers, and combines a dual-port polarized antenna with a self-tunable cancellation circuit. The second design proposal targets even more compact radio devices such as smartphones and sensor network nodes. This design builds on a tunable electrical balance isolator/duplexer in combination with a single-port miniature antenna. The electrical balance circuit can be implemented for scaled CMOS technology, facilitating low cost and dense integration.

Apparatus and method for antenna alignment

Abstract: Apparatus comprising a first antenna configured to receive alignment signalling from a first transmitter over a first communication channel, the first communication channel having a first set of characteristics, and a second antenna configured to exchange data w.th a second transmitter over a second communication channel, the second communication channel having a second different set of characteristics. The apparatus also comprising a processor configured to process the alignment signalling received from the first antenna and determine the location of the second transmitter relative to the apparatus; and generate control signalling representative of the determined location of the second transmitter relative to the apparatus. The apparatus further comprising a user interface configured to provide a user with an indication of the relative location of the second transmitter relative to the apparatus in accordance with the control signalling to allow for the second antenna to be aligned for data exchange with the second transmitter.

Receiver circuit for multiple carriers

Abstract: A receiver circuit comprising a connection portion (20) for guiding each one of a first predefined number of carrier signals of multiple carriers to one of a number of receive branches, each receive branch comprising at least one amplifier load structure, the number of receive branches being equal to the first predefined number. The receiver circuit also comprises a mixing portion (30) for generating a second predefined number of mixed carrier signals on each receive branch by mixing a carrier signal on each one of the receive branches with a number of local oscillator frequencies equal to the second predefined number, and a selection portion (40) for selecting one of the second predefined number of mixed carrier signals on each receive branch to be output via a number of output paths equal to the first predetermined number to a digital data path.