Topic
Active antenna
About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.
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TL;DR: This paper proposes a method of improving the channel estimates for non-coherent multi-antenna terminals, which are terminals that cannot control the relative phase between its antenna ports, with channels that can be considered constant over multiple time slots.
Abstract: In this paper, we propose a method of improving the channel estimates for non-coherent multi-antenna terminals, which are terminals that cannot control the relative phase between its antenna ports, with channels that can be considered constant over multiple time slots. The terminals have multiple antennas and are free to choose whichever antenna they want to use in each time slot. An unknown phase shift is introduced in each time slot as we cannot guarantee that the terminals are phase coherent across time slots. We compare three different clustering techniques that we use to detect the active antenna. We also compare a set of different statistical and heuristic estimators for the channels and the phase shifts. We evaluate the methods by using correlated Rayleigh fading and three different bounds on the uplink capacity. The accuracy of the capacity bounds are verified with bit-error-rate simulations. With our proposed methods we can have an SNR improvement of approximately 2 dB at 1 bit/s/Hz.
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30 Jul 2015
TL;DR: In this article, a beam-space MIMO-based communication device is described, and an operation method for the communication device according to an embodiment of the present invention is presented.
Abstract: Disclosed are a beam-space MIMO-based communication device, and an operation method therefor The communication device according to an embodiment of the present invention may comprise: a beam-space MIMO antenna containing an active antenna and a plurality of parasitic antennas which mutually couple to the active antenna; a beam-space MIMO baseband circuit for generating a load impedance vector for the plurality of parasitic antennas using a signal in a time region transmitted from a modem circuit; and a beam-space MIMO RF circuit for loading, on each of the plurality of parasitic antennas, the load impedance value corresponding to each of the plurality of parasitic antennas on the basis of the load impedance vector
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04 Feb 2021TL;DR: In this paper, the authors present a system and methods related to determining and using a codebook in a virtualized active antenna system (AAS) based on a port-to-antenna mapping matrix.
Abstract: Systems and methods are disclosed herein that related to determining and using a codebook in a virtualized Active Antenna System (AAS). In some embodiments, a first radio node that is configured to communicate with a second radio node comprises a radio interface and processing circuitry configured to transform a first codebook that is in a non-virtualized antenna domain to a second codebook that is in a virtualized antenna domain based on a port to antenna mapping matrix used to transform a signal from the virtualized antenna domain to the non-virtualized antenna domain prior to transmission of the signal in a corresponding virtualized cell or sector. The processing circuitry is further configured to receive a transmit signal from the second radio node to thereby provide a received signal and perform Precoding Matrix Indication (PMI) estimation based on the received signal using the second codebook in the virtualized antenna domain.
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21 Mar 2013TL;DR: In this paper, a radar device consisting of a RF signal source, two or more antenna interface units, a feed network, and a control unit is described, where the control unit 15 is arranged to activate and deactivate the buffers in dependence on the selection signal.
Abstract: A radar device 10 comprising a RF signal source 12 (RF = radar frequency), two or more antenna interface units, a feed network 13, and a control unit 15 is described. The RF signal source 12 is arranged to provide a RF signal; each of the antenna interface units comprises an antenna port 21; 23; 25; 27 and one of the following 22; 24; 26; 28: an amplifier and a mixer; wherein the amplifier is arranged to amplify the RF signal and to provide it to the antenna port and the mixer is arranged to generate an intermediate frequency signal by mixing the RF signal with a reception signal received via the antenna port 21; 23; 25; 27; the feed network 13 comprises two or more buffers 36, 38, 40, 42, each buffer has an active state, in which the buffer is transmissive for the RF signal, and an inactive state, in which the buffer is substantially nontransmissive for the RF signal; the control unit 15 is arranged to generate or receive a selection signal (SEL) which specifies none, one 22, or more 22, 24 of the antenna interface units 22, 24, 26, 28 as active antenna interface units and the remaining none, one, or more antenna interface units 22, 24, 26, 28 as inactive antenna interface units; the control unit 15 is arranged to activate and deactivate the buffers in dependence on the selection signal so as to feed the RF signal to the none, one, or more active antenna interface units and not to the none, one, or more inactive antenna interface units. A method of operating a radar device is also proposed.