Haiming Wang | Southeast University (China) (original) (raw)

Papers by Haiming Wang

This paper presents an overview of a new very high throughput millimeter-wave WLAN system operati... more This paper presents an overview of a new very high throughput millimeter-wave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj (45GHz). Then the fre-quency spectrum allocation at 45 GHz band is intro-duced. Next, the channel measurement and modeling is given. Specifically, the millimeter-wave MIMO for physical layer enhancement is given in detail.

A wideband millimeter-wave reflectarray antenna is investigated. First, using the microstrip tech... more A wideband millimeter-wave reflectarray antenna is investigated. First, using the microstrip technique, a new dual-resonance unit cell is proposed for the reflectarray, which provides an approximately linear phase response of 0 • –360 • range. Additionally , its phase response curves are nearly parallel within a broad band, which can widen the operating bandwidth of the reflectarray antenna. Then, using the proposed unit cells, a 1296-element re-flectarray antenna is designed, fabricated, and measured. Finally, measured results show that the boresight gain is 31.9 dBi and the 1-dB bandwidth is greater than 29.3% at Q-band. Simulation and measurement results agree very well with the proposed design scheme.

In this letter, an improved channel estimator for MIMO-SCBT systems is proposed. Pilot blocks are... more In this letter, an improved channel estimator for MIMO-SCBT systems is proposed. Pilot blocks are constructed using quadriphase complementary sequences (QCSs) which enable both one-sided (OSD) and two-sided (TSD) channel estimation (CE). And OSD-CE and TSD-CE are combined to provide improved performance in frequency-selective fast and slow fading channels and to maintain low-complexity implementations. Simulation results demonstrate the performance merits of the proposed scheme. key words: channel estimator, multiple-input and multiple-output (MIMO), single-carrier block transmission (SCBT), quadriphase complementary sequences (QCSs)

Low complexity channel estimation for single-carrier block transmission systems over multiple-inp... more Low complexity channel estimation for single-carrier block transmission systems over multiple-input multiple-output time varying frequency-selective channels is investigated. A time slot structure that uses Golay complementary sequences with perfect periodic autocorrelations as two-sided pilot blocks is presented. Employing this strucutre, optimal least square estimate in the minimum mean square error (MMSE) sense is achieved. Furthermore, a computationally efficient algorithm which is named as fast periodic Golay correlation is proposed based on the specific generator and the properties related to circulant matrices. Finally, the simulation results show the MMSE performance of the proposed scheme and algorithm.

Two single fed low-profile cavity-backed slot antennas and an antenna array for circular polariza... more Two single fed low-profile cavity-backed slot antennas and an antenna array for circular polarization (CP) applications are introduced. By employing the substrate-integrated waveguide (SIW) and half-mode SIW (HMSIW) techniques in antenna designs, low-profile cavity-backed structures are realized using the low-cost standard printed circuit board process. First, a novel spoon-shaped slot antenna is proposed to realize CP radiation based on the SIW cavity. Then, to minimize the antenna size and achieve the impedance bandwidth enhancement, the HMSIW cavity is introduced to realize a cavity-backed semicircle slot antenna (SSA). The equivalence between the edge of the HMSIW cavity and the longitude slot curved on the surface of the SIW cavity is proposed to guide the design process of the SSA. In addition, two hybrid modes are used to improve the impedance bandwidth of the SSA. Furthermore, a sequential rotation antenna array is introduced to validate the feasibility of the SSA for antenna array application. Finally, the proposed antennas and the antenna array are designed and fabricated at 28 GHz. The measured and simulated results agree very well. Index Terms— Array antenna, cavity-backed antennas, circular polarization (CP), half-mode substrate-integrated waveguide (HMSIW), SIW.

A new design of primary synchronization signal (PSS) sequences and an efficient detection algorit... more A new design of primary synchronization signal (PSS) sequences and an efficient detection algorithm for multi-beam satellite long-term evolution (LTE) systems are investigated in this paper. First, a transmit-timing adjustment method is proposed to reduce the large time difference of arrival of received signals from different satellites. Then, using the particular subcarrier mapping scheme of LTE, original Zadoff–Chu sequences are generalized to obtain more candidate sequences with good correlation properties. Later on, choosing an optimal subset from these candidate sequences, new PSS sequences for seamless global coverage multi-beam satellite-LTE systems are obtained. Subsequently, an efficient synchronization and low complexity PSS detection algorithm using interference cancellation method is presented. Finally, simulation results verify the effectiveness of the proposed scheme.

Mutually orthogonal periodic complementary sequence sets (MOPCSS) and their application are inves... more Mutually orthogonal periodic complementary sequence sets (MOPCSS) and their application are investigated in this letter. A new generator for quadriphase MOPCSSs is first presented, which uses a unitary-like matrix as a seed matrix. Next, a new design of pilot sequences using MOPCSSs for multiple-input and multiple-output (MIMO) single-carrier block transmission (SCBT) systems is given. Later on, an optimized periodic Golay correlator is proposed to efficiently implement the least square MIMO channel estimation. Finally, the optimal performance of the channel estimation is verified via simulation .

In this letter, we first present a new construction method for uncorrelated binary periodic Compl... more In this letter, we first present a new construction method for uncorrelated binary periodic Complementary sequence sets (CSS). Next, the uncorrelated periodic CSSs are used as pilot sequences for multiple-input multiple-output (MIMO) channel estimation. Later on, we propose a low-complexity periodic correlator. Finally, simulation results verify the optimality of pilot sequences for MIMO channel estimation. key words: binary periodic complementary sequence sets, periodic corre-lator, channel estimation

A dual-band dual-circularly polarized (CP) antenna fed by a dual-band 3-dB substrate integrated c... more A dual-band dual-circularly polarized (CP) antenna fed by a dual-band 3-dB substrate integrated coaxial line coupler is designed, fabricated, and measured. The proposed antenna is excited by two planar L-probes that are connected to two output ports of the coupler. This dual-band dual-CP antenna effectively covers the L-band of 1.62 GHz and S-band of 2.50 GHz, respectively. Simulation and measurement results show that, considering reflection coefficient, gain, and axial ratio together, the relative bandwidth is about 10% at the lower band and about 4% at the upper band. The maximum measured antenna gains are 8.5 and 8.2 dBi, respectively.

A dual-band substrate integrated coaxial line (SICL) 3-dB branch-line coupler and its compact rea... more A dual-band substrate integrated coaxial line (SICL) 3-dB branch-line coupler and its compact realization are proposed in this letter. The SICL coupler with the compact structure shows a comparable performance and great size reduction compared with the conventional structure. The simulated and measured results match very well.

—The channel measurement and modeling of large-scale fading characteristics of 45-GHz band in thr... more —The channel measurement and modeling of large-scale fading characteristics of 45-GHz band in three typical indoor environments are investigated. An automatic measurement system owning a sufficient dynamic range is designed to overcome the prominent attenuation in 45-GHz band. After conducting extensive measurements, large-scale fading characteristics including path-loss exponent, cross-polarization discrimination ratio, and standard deviation of shadow fading are obtained and compared in different scenario setups. Goodness-of-fit test is applied to validate whether the assumed log-normal distribution can describe the shadow fading characteristics.

Using the differential evolution algorithm (DEA), low-sidelobe-level (SLL) series-fed microstrip ... more Using the differential evolution algorithm (DEA), low-sidelobe-level (SLL) series-fed microstrip antenna arrays of unequal interelement spacing (IES) are investigated. The proposed design method can achieve conversion between the SLL and half-power beamwidth (HPBW). The constraint conditions for the IES and amplitude are set up, and the element size is also taken into account in the pattern function. Based on the solutions from the DEA, two types of series-fed antenna arrays of unequal IES, i.e., uniform amplitude and nonuniform amplitude arrays, are designed, fabricated, and measured. Measurement results show that 8-and 10-element series-fed antenna arrays of unequal IES and nonuni-form amplitude can achieve the SLL of −23.7 dB with HPBW of 9.7 • and the SLL of −25.3 dB with HPBW of 8.3 • , respectively. Compared to the traditional design methods, the proposed one can achieve the series-fed antenna array with a lower SLL and more narrow HPBW. Index Terms—Differential evolution algorithm (DEA), low side-lobe level (SLL), series-fed antenna array, unequal interelement spacing (IES).