Space-time diversity for active antenna systems

This paper presents a radio frequency (RF) continuous-time band-pass delta sigma modulator (CT BP DSM) receiver realized in a 180 nm SiGe BiCMOS technology. It also provides an introduction to active antenna systems (AAS) for cellular infrastructure base stations, which is the target application for this RF integrated circuit (IC). The internal quantizer and feedback digital to analog converter (DAC) resolution of the CT BP DSM is 2 bit. Without applying DAC linearization techniques such as trimming or dynamic element matching being utilized, measured performance parameters include an SNR and SNDR in 35 MHz bandwidth of 56.7 and 53.7 dB, respectively. IIP3 and noise figure are −6.6 dBm and 10 dB, respectively. No image reception is noticeable within a measurement dynamic range of 83 dB. When driven by single-carrier and three-carrier W-CDMA signals, adjacent channel leakage ratio (ACLR) is −62.6 and −52.1 dB, respectively, making the design also suitable as a modulator for a class-S power amplifier.

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Challenges of Millimeter-Wave Active Antenna Systems in 5G

12th European Conference on Antennas and Propagation (EuCAP 2018) ◽

10.1049/cp.2018.0940 ◽

2018 ◽

Author(s):

U. Gustavsson ◽

M. Johansson ◽

F. Athley ◽

A. Zaidi

Keyword(s):

Millimeter Wave ◽

Active Antenna ◽

Antenna Systems

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Combined space/time diversity technique for narrowband TDMA mobile radio systems

Electronics Letters ◽

10.1049/el:19890669 ◽

1989 ◽

Vol 25 (15) ◽

pp. 1001 ◽

Cited By ~ 1

Author(s):

L.B. Lopes

Keyword(s):

Space Time ◽

Mobile Radio ◽

Time Diversity ◽

Mobile Radio Systems ◽

Radio Systems ◽

Diversity Technique

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Joint Angular and Time Diversity of Multi-Antenna CDMA Systems in Wireless Fading Channels

International Journal of Wireless Networks and Broadband Technologies ◽

10.4018/ijwnbt.2011010101 ◽

2011 ◽

Vol 1 (1) ◽

pp. 1-14

Author(s):

Feng She ◽

Hsiao Hwa Chen ◽

Hongyang Li

Keyword(s):

Fading Channels ◽

Performance Improvement ◽

Multipath Fading ◽

Antenna System ◽

Space Time ◽

Diversity Gain ◽

Multipath Fading Channel ◽

Time Diversity ◽

Time Domains ◽

Code Division Multiple

In this paper, a multi-antenna based receiver structure for direct sequence code division multiple access (DS/CDMA) system is proposed. The proposed scheme exploits the excellent time resolution of a CDMA RAKE receiver and uses an antenna array beamforming structure to resolve multipath returns in both angular and time domains. A much higher diversity gain than that based only on the time domain diversity can be achieved. This work suggests a new space-time diversity paradigm, namely angular-time diversity, which differs from traditional Alamouti-type space-time coded schemes. The impairments caused by multipath and multiuser interference are analyzed. The performance of the proposed receiver in multipath fading channel is explicitly evaluated. An expression for uncoded system bit error probability is derived. Simulation results show the performance improvement in terms of BER due to the use of multi-antenna in the receiver, and the results illustrate that the multi-antenna based receiver works effectively in resolving multipaths in both angular and time domains to achieve performance improvement due to angular and time diversity gain provided by the multi-antenna system.

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