| 1. |
- An, Sining, 1991, et al.
(författare)
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A 40 Gbps DQPSK Modem for Millimeter-wave Communications
- 2016
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Ingår i: Asia-Pacific Microwave Conference Proceedings APMC 2015. ; 1
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Konferensbidrag (refereegranskat)abstract
- A high speed differential quadrature phase shift keying (DQPSK) modulator and demodulator (modem) is presented for data rates up to 40 Gbps, in which the modulator is based on an FPGA and the demodulator is based on analog components. The modem performance has been verified in a lab environment. The targeted application is wireless communications using millimeter-wave bands as a flexible alternative to optical fiber links in next generation mobile networks.
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| 2. |
- An, Sining, 1991, et al.
(författare)
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An 8 Gbps E-band QAM Transmitter Using Symbol-based Outphasing Power Combining Technique
- 2017
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Ingår i: Radio-Frequency Integration Technology (RFIT2017). - 9781509040360 ; , s. 150-152
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Konferensbidrag (refereegranskat)abstract
- In millimeter-wave communication systems, generating high output power with high efficiency on the transmitter side is one major challenge. In this paper, a symbol-based outphasing power combining solution has been demonstrated with data rate up to 8 Gbps at an RF frequency of 83.5 GHz. This solution provides 2 dB higher output power compared to the power of two QAM signals at 12% EVM.
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| 3. |
- Bao, Mingquang, 1962, et al.
(författare)
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A High-Speed Power Detector for D-Band Communication
- 2014
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 62:7, s. 1515-1524
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Tidskriftsartikel (refereegranskat)abstract
- A D-band power detector (PD) consisting of a four-way power divider and four identical active PD units is proposed, where four individual PD units are derived by the input signals having the same amplitude, but a 90 degrees phase difference. The outputs of the PD units are combined, to suppress the first, second, and third harmonics due to phase cancellation. Consequently, the ripple at the output is minimized. The proposed PD is designed and manufactured in a 0.25-mu m InP DHBT technology, which is characterized by on-chip measurements with both a sinusoidal signal and a binary amplitude shift-keying modulated signal at a data rate up to 13 Gb/s over different carrier frequencies from 100 to 150 GHz. Measured bit error rate for a 2(7) - 1 pseudorandom binary sequence is less than 10(-12) at the carrier frequency of 120 GHz, and less than 1.7 x 10(-5) at the carrier frequency of 150 GHz. In addition, the proposed PD achieves state-of-the-art power/energy efficiency, which exhibits the lowest energy per bit of 1.1 pJ/bit. Total dc power consumption of the PD is 15 mW.
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| 4. |
- Chen, Jingjing, 1982, et al.
(författare)
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10 Gbps 16QAM transmission over a 70/80 GHz (E-band) radio test-bed
- 2012
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Ingår i: European Microwave Week 2012: "Space for Microwaves", EuMW 2012, Conference Proceedings - 7th European Microwave Integrated Circuits Conference, EuMIC 2012. - : IEEE. - 9782874870286 - 9781467323024 - 9782874870262 ; , s. 556-559
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Konferensbidrag (refereegranskat)abstract
- A millimeter-wave radio test-bed is implemented which demonstrates 16QAM transmission over 70/80 GHz band for data rate up to 10 Gbps. Performance of the 16QAM transmitter and receiver is evaluated in a loop-back lab set-up. With the proposed 10 Gbps on single carrier system architecture, it is possible to achieve 40 Gbps over a 5 GHz bandwidth when combined with polarization and spatial multiplexing.
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| 5. |
- Chen, Jingjing, 1982, et al.
(författare)
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A data-rate adaptable modem solution for millimeter-wave wireless fronthaul networks
- 2015
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Ingår i: 2015 IEEE International Conference on Communication Workshop, ICCW 2015. - 2164-7038. - 9781467363051 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- For dense small cell deployment in centralized baseband architecture, wireless fronthaul is a cost efficient and flexible alternative to fiber-based fronthaul links. Due to the available wide bandwidth, millimeter-wave technology is the most promising choice to realize multi-gigabit wireless transmission of the common public radio interface (CPRI). In this paper, we present a novel differential encoding scheme for differential quadrature phase-shift keying (D-QPSK) modulation, which enables data-rate adaptable CPRI transmission without modification of a standard receiver. A multi-rate D-QPSK modulator/demodulator (modem) is implemented and tested for data rates up to 10 Gbps, limited by the bandwidth of the microwave components in use. This modem is verified to fulfill the CPRI specifications with respect to multi-rate, low latency and high system performance. Therefore, it is proposed for the implementation of wireless CPRI links at millimeter-wave bands.
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| 6. |
- Chen, Jingjing, 1982, et al.
(författare)
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An Energy Efficient 56 Gbps PAM-4 VCSEL Transmitter Enabled by a 100 Gbps Driver in 0.25 µm InP DHBT Technology
- 2016
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 34:21, s. 954-4964
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Tidskriftsartikel (refereegranskat)abstract
- Datacenters demand higher speed VCSEL-based optical interconnects at low power consumption. As a potential technology enabler, this paper presents a wide bandwidth and energy efficient multilevel PAM VCSEL driver implemented in an InP 0.25 μm double heterojunction bipolar transistor (DHBT) technology. The operational bandwidth of the driver is verified and error-free electrical data transmission up to 56 Gbps PAM-2 and 100 Gbps PAM-4 is demonstrated at a driver energy consumption less than 2 pJ/bit. The driver is integrated and tested with an in-house fabricated 850 nm VCSEL. Error-free 56 Gbps PAM-4 optical transmission at a transmitter energy consumption of 3.7 pJ/bit is demonstrated without equalization. This is the highest data rate reported for an integrated PAM-4 modulated VCSEL transmitter, while being the most energy efficient above 40 Gbps operation. Moreover, the VCSEL driver offers a pre-emphasis feature at PAM-2 operation for improved link throughput and receiver sensitivity.
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| 7. |
- Chen, Jingjing, 1982, et al.
(författare)
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Demonstration of analog millimeter-wave fronthaul for 64-QAM LTE transmission
- 2015
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Ingår i: IEEE Vehicular Technology Conference. - 1550-2252.
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Konferensbidrag (refereegranskat)abstract
- Centralized baseband architecture is believed to be cost efficient and to offer high network performance. The fronthaul network, connecting the centralized baseband to distributed remote radios, requires high capacity and low latency transport links, due to the stringent specifications of the data interface, known as common public radio interface (CPRI). Today, fronthaul links are mostly based on digital CPRI over fibers, although it is possible to realize CPRI over wireless technology with the drawback of poor bandwidth efficiency. In this paper, we propose an analog wireless fronthaul concept to enable bandwidth efficient and scalable fronthaul networks. The basic idea is to transport narrow band analog radio signals over millimeter-wave bands instead of multi-gigabit digital signals. The phase and frequency impairments introduced by high frequency carriers are effectively reduced using an analog pilot-based mitigation technique. As a proof-of-concept demonstration, an analog fronthaul link is implemented, and the link performance is verified for 20 MHz 64-QAM LTE transmission over 70/80 GHz (E-band). The measured error vector magnitude (EVM) is about 3% with 10% pilot bandwidth overhead.
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| 8. |
- Chen, Jingjing, 1982, et al.
(författare)
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Does LO Noise Floor Limit Performance in Multi-Gigabit Millimeter-Wave Communication?
- 2017
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 27:8, s. 769-771
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Tidskriftsartikel (refereegranskat)abstract
- Extremely high data rate communication can potentially be achieved by combining high-order modulations and wide bandwidths at millimeter-wave (mm-wave) frequencies. However, it has been challenging to practically implement this combination, even if the SNR of the system appears to be sufficiently high. An explanation from a recent theoretical study is that the practical data rates in mm-wave systems are limited by the local oscillator (LO) white phase noise. In this letter, we present an experimental investigation on whether the white noise floor of frequency multiplied LO sources is a major noise contribution to wideband signals. Hardware measurements are performed using multi-gigabit 64 quadrature amplitude modulation (QAM) signals. The measured results show that the transmitter performance degrades as the LO noise floor increases. Hence, the LO noise floor is identified to be one primary limitation for achieving the highest possible data rate in wideband mm-wave systems.
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| 9. |
- Chen, Jingjing, 1982, et al.
(författare)
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Experimental demonstration of RF-pilot-based phase noise mitigation for millimeter-wave systems
- 2014
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Ingår i: IEEE Vehicular Technology Conference. - 1550-2252. - 9781479944491 ; , s. Art. no. 6965978-
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Konferensbidrag (refereegranskat)abstract
- Millimeter-wave bands are gaining popularity for high data rate wireless communication systems due to the wide available bandwidth. However, oscillator phase noise also increases as the carrier frequency increases. Methods of phase noise mitigation are therefore crucial for future millimeter-wave systems. In this work, we propose to adopt analog phase noise mitigation using an RF-pilot tone, which reduces both phase and frequency impairments of an arbitrary millimeter-wave signal at the expense of reduced spectral efficiency. The method is verified experimentally at carrier frequency of 28 GHz and E-band 73 GHz showing a 20 dB noise reduction up to 100 kHz offset. Since the method relaxes phase noise requirement it is attractive for phase noise sensitive technologies at high carrier frequency, such as OFDM used in LTE. As indicated by the simulation results, the reduced phase noise enables a LTE signal on a millimeter-wave carrier with marginal performance impact.
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| 10. |
- Chen, Jingjing, 1982, et al.
(författare)
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Influence of White LO Noise on Wideband Communication
- 2018
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 66:7, s. 3349-3359
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Tidskriftsartikel (refereegranskat)abstract
- Applying a spectrally efficient modulation to a wideband signal provides an extremely high data rate potential in millimeter-wave communication. In reality, wideband systems, as reported in open literature, typically suffer from insufficient signal-to-noise ratio (SNR) and thus are not able to support high-order modulation. In a recent experimental study, we have identified that a high noise floor from frequency-multiplied local oscillator (LO) sources is a major data rate limitation in wideband systems. In this paper, we present a detailed study with a mathematical model to describe the influence of the LO noise on a communication signal through frequency conversion. Followed by experimental investigations using multigigabit 64-quadrature amplitude modulation signals, measurements are performed at frequency up- and down-conversions. Both cases show SNR degradation on the frequency-converted signals as the corresponding LO noise floor increases. We provide experimental proof that the nature of the LO noise floor is white, with nearly the same amount of phase and amplitude noises. Various ways to reduce the white LO noise floor through the new hardware design are discussed providing design requirements and considerations.
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