Browsing by Author "Wu, Chang-Ting"

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A Millimeter Wave Digital CMOS Baseband Transceiver for Wireless LAN Applications
(2019-01-01)
Chiu, Kang-Lun
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Chan, Hsun-Wei
;
Lee, Wei-Che
;
Wu, Chang-Ting
;
Lopez, Henry
In this paper, we introduce a 10 Gbps digital baseband transceiver with IV supply voltage, 16-QAM, 3/4 code rate single carrier mode using 28 nm CMOS process to do the implementation. In millimeter wave communications, well-defined standard, IEEE 802.11ad is referenced for our system design and simulation. We target at modified chip rate 2.5 GHz with 4 times parallelism hardware at clock rate 625 MHz. The overall transceiver architecture design with hardware implementation considerations will be proposed. With the smart shared memory allocation, we can reduce 31% of the total amount. According to the referenced specifications, we achieve the required bit error rate 3 x 10(-7) before SNR 18.5 dB. After the system algorithm design, we implement the hardware with the core area 2.92 mm(2) with measured power 1.8 Watt for baseband transceiver chip. The performance of energ,y per bit is 0.023 nJ and 0.211 nJ per hit 6w Tx and Rx, including ADC/DAC.
A MMSE Joint Feedback Feed-forward Equalizer for FBMC-OQAM Baseband Receiver in the 60 GHz Band
(2017-12-01)
Liu, Chun-Yi
;
Leong, Edmund Wen Jen
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Wu, Chang-Ting
;
Sie, Meng-Siou
;
Lopez, Henry
In this paper, a minimum mean square error (MMSE) joint feedback feed-forward equalizer (MJFFE) is proposed to deterministically suppress the inter-symbol interference and inter-carrier interference that arose from the filter bank multi-carrier in a long multipath channel of the 60-GHz indoor wireless transmission. The decision device is discarded in the decision feedback loop to reduce error propagation while at the same time applying the MMSE criterion to prevent over compensation influenced by additive white Gaussian noise. As a result, in an non-line-of-sight (NLOS) channel with 7.65-ns rms delay spread, a 3-tap MJFFE provides 3-dB improvement at the bit error rate (BER) 10(-2) crossing and improve error floor effect at the BER 10(-3) crossing, as compared with the 1-tap zero-forcing equalizer. Furthermore, the proposed equalizer coefficients calculation based on linear convolution for the MJFFE is also presented. The hardware complexity achieves 50% reduction by using several methods including multiplexing, memory sharing, and computation element sharing.
A Pseudo MMSE Linear Equalizer for 60GHz Single Carrier Baseband Receiver
(2017-01-01)
Chan, Hsun-Wei
;
Wu, Chang-Ting
;
Jen, Chih-Wei
;
Liu, Chun-Yi
;
Lee, Wei-Che
In this paper, a pseudo minimum mean square error (P-MMSE) frequency domain equalizer (FDE) is proposed to combat deep fading channel for single carrier (SC) modulation under IEEE 802.11ad and IEEE 802.15.3c standard. This FDE has resistance like MMSE to deep fading channel and maintain low complexity like zero-forcing (ZF) equalizer. In order to calculate bit error rate (BER) performance, the proposed P-MMSE integrating with our previous dual-mode baseband receiver [1] to do simulation. P-MMSE FDE can provide about 1dB improvement for 16QAM and 5 dB improvement for QPSK and BPSK when BER at 10(-2) in serious deep fading channel. Besides, it enhances the BER floor from 4 x 10(-3) to 10(-3) in 16-QAM. Moreover, P-MMSE FDE maintains the same complexity as ZF FDE.