An 802.11ax 4 \times 4 High-Efficiency WLAN AP Transceiver SoC Supporting 1024-QAM With Frequency-Dependent IQ Calibration and Integrated Interference Analyzer

• Published in: IEEE journal of solid-state circuits 2018-12, Vol.53 (12), p.3688-3699
• Main Authors: Kawai, Shusuke, Ito, Rui, Nakata, Kengo, Shimizu, Yutaka, Nagata, Motoki, Takeuchi, Tomohiko, Kobayashi, Hiroyuki, Ikeuchi, Katsuyuki, Kato, Takayuki, Hagiwara, Yosuke, Fujimura, Yuki, Yoshioka, Kentaro, Saigusa, Shigehito, Yoshida, Hiroshi, Arai, Makoto, Yamagishi, Toshiyuki, Kajihara, Hirotsugu, Horiuchi, Kazuhisa, Yamada, Hideki, Suzuki, Tomoya, Ando, Yuki, Nakanishi, Kensuke, Ban, Koichiro, Sekiya, Masahiro, Egashira, Yoshimasa, Aoki, Tsuguhide, Onizuka, Kohei, Mitomo, Toshiya
• Format: Article
• Language: English
• Subjects: 80211ax; Calibration; error vector magnitude (EVM); image rejection ratio (IRR); In-phase and quadrature (IQ) mismatch; Interference; Mathematical model; OFDM; Radio frequency; Transceivers; Wireless LAN; wireless LAN (WLAN)
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2018.2877168

A fully integrated 4 \times 4 802.11abgn/ac/ax transceiver system-on-chip (SoC) with integrated interference analyzer and frequency-dependent in-phase and quadrature (IQ) (FD-IQ) calibration is presented. The FD-IQ technique helps meeting the extremely strict IQ imbalance requirement for 1-K quadratic-amplitude modulation (QAM). The pure current-mode TX baseband (BB) improves SNR to better than 50 dB, and a multi-mode local oscillator (LO) distribution circuit provides non-contiguous operation with the error vector magnitude (EVM) of less than −37 dB. The integrated interference analyzer achieves the highly reliable connection in the presence of the undesired signal and hence improves the frequency usage efficiency by identifying the wireless LAN (WLAN) and other signals in the 2G/5G band.