Suiyan Geng

Millimeter-Wave Propagation Channel Characterization for Short-Range Wireless Communications

This paper presents and analyzes the results of millimeter-wave 60-GHz frequency range propagation channel measurements that are performed in various indoor environments for continuous-route and direction-of-arrival (DOA) measurement campaigns. The statistical parameters of the propagation channel, such as the number of paths, the RMS delay spread, the path loss, and the shadowing, are inspected. Moreover, the interdependencies of different characteristics of the multipath channel are also investigated. A linear relationship between the number of paths and the delay spread is found, negative cross correlation between the shadow fading and the delay spread can be established, and an upper bound exponential model of the delay spread and the path loss is developed to estimate the worst case of the RMS delay spread at given path loss. Based on the DOA measurements that are carried out in a room [line of sight (LOS)] and in a corridor with both LOS and nonline-of-sight (NLOS) scenarios, radio-wave propagation mechanisms are studied. It is found that considering the direct wave and the first-order reflected waves from smooth surfaces is sufficient in the LOS cases. Transmission loss is very high; however, diffraction is found to be a significant propagation mechanism in NLOS propagation environments. The results can be used for the design of 60-GHz radio systems in short-range wireless applications.

Polarization Behaviours at 2, 5 and 60 GHz for Indoor Mobile Communications

The behaviours of linear polarizations at 2.15, 5.3 and 61.7 GHz in corridors are studied in this paper. It shows that there is no significant difference between the received powers for vertical and horizontal polarizations. Depolarization is obvious at 2.15 GHz due to different antenna type is applied at the receiver, and it is more serious in non-line-of-sight (NLOS) cases.

Multipath propagation characterization of ultra-wide band indoor radio channels

This paper presents the results of ultra-wide band (UWB) indoor channel measurements performed in a hall, a meeting room, and a corridor with both LOS and NLOS scenarios. The channel multipath propagation characteristics are investigated by examining the power delay profiles, path loss, power distribution, and rms delay spread. It is found that in UWB channels, the appearance of multipath components are in the forms of diffuse, single dominant and clustered paths, their appearance is highly dependent on the measurement environments. UWB radio is robust to multipath fading due to the small fading margin and the high multipath diversity gain it has. Moreover, the UWB measurement results are compared with the results obtained in traditional wideband 60 GHz indoor channels.

Frequency and Bandwidth Dependency of UWB Propagation Channels

In this paper, based on indoor ultra-wide band (UWB) propagation channel measurements for both LOS and NLOS scenarios, the frequency dependency of propagation in the 3-10 GHz UWB range is investigated by examining the power delay profile, rms delay spread, path loss and shadowing as functions of frequency. Moreover, the bandwidth dependency of channel parameters is also investigated for gaining more understanding of the general channel properties

Experimental Investigation of the Properties of Multiband UWB Propagation Channels

In this paper, the link budget of the multiband UWB channel is studied based on empirical analysis of path loss and shadow fading by dividing the frequency range into multiple sub- bands with 500 MHz bandwidth. The work is based on ultra- wide band (UWB) propagation measurements performed in two indoor environments of a hall and a corridor in the frequency range of 3-10 GHz. It is found that in the multiband channels, the path loss exponent is independent on frequency, and the mean path loss can be modelled as a function of frequency. Shadowing (in dB) fits well with normal distribution, and the standard deviation (STD) of shadowing shows a tendency of increasing with frequency. Furthermore, the shadow fading margin with 90% link success probability is found to bee fairly low (less than 4 dB) the multiband channels. The presented results can be used for design of UWB radio systems.

Millimeter-Wave Propagation in Indoor Corridors

In this letter, ray-based models for both line-of-sight (LOS) and non-line-of-sight (NLOS) indoor corridors are presented and compared with results of propagation measurements performed at millimeter (mm)-waves in the 60-GHz frequency band. It is shown that in the LOS corridor case, signals propagate like in free space and in a guided fashion in near and far zones, respectively. A nine-ray model (LOS path plus four first-order and four second-order reflections from the corridor walls, ground, and ceiling) is found to be suitable in characterizing propagation signals in far zone in this environment. In the NLOS corridor case, multiray models with a heuristic diffraction coefficient are used in the field simulation. Results show that a model with eight rays is adequate in characterizing both average power and variation of signals. However, in characterizing the average decay of signal power, only two diffracted rays are needed. Also, empirical models given for NLOS corridors cases indicate that diffraction is the dominant propagation phenomenon in the environment. Furthermore, multipath power distributions are investigated. It is found that Rayleigh and double-Rayleigh distributions are the bounds for both the LOS and NLOS data. Multiple-Rayleigh distribution can fit the measurement data very accurately.

Propagation characterization of wideband indoor radio channels at 60 GHz

This paper presents the results of indoor propagation measurements performed in a corridor (LOS) and a hall with both LOS and NLOS measurement routes at 60 GHz. The channel dispersion and fading effects are analyzed by examining the rms delay spread, path loss and shadowing. Moreover, the correlation properties between dispersion and fading effects are investigated, and negative cross-correlation is found between rms delay spread and shadowing fading. An upper-bound exponential model of rms delay spread and path loss is developed for estimating the worst case of rms delay spread at given path loss

Mm-wave MIMO systems for high data-rate mobile communications

In this paper, the performance of 60 GHz MIMO system is analyzed based on experimental data. The mutual information (MI) of the measured channel is compared to the MI of an iid MIMO Rayleigh channel. It is seen that the mean MI of the channels are quite close to each other. Then, the MI of the MIMO system is compared to the one of a MIMO system with antenna selection. It is found that, when considering switching networks with realistic losses, the performance decreases drastically and, in most cases, MIMO antenna selection leads to lower MI than traditional MIMO with the same number of RF chains. Finally, the achievable data-rate of a realistic 4×4 MIMO system is calculated, based on the experimental data. It is shown that with 500 MHz bandwidth such a system can provide multigigabit communications at distance up to 10m.

Performance and capacity analysis of 60 GHz MIMO channel for WPANs

The 60 GHz radio is being foreseen as a very promising candidate for future gigabit wireless communications due to the intrinsic large amount available bandwidth. This band has been proposed for wireless personal area networks (WPANs) [1][2] aiming at multi-gigabit and short-trange (≪10 m) multimedia applications. The 60 GHz band regulation and standardization efforts are currently underway worldwide [1].

Feasibility study of emerging high throughput radio systems

In this paper, the feasibilities of emerging high throughput radio channels are investigated. Specifically, the performance and capacities of ultrawide band (UWB), 5 GHz multiple-in and multiple-out (MIMO) and 60 GHz MIMO radio channels are studied based on regulations and standardization in IEEE 802.15.3a, 802.11n and 802.15.3c, respectively. The analysis shows that in the UWB channel for single-in and single-out (SISO) transmission, it is difficult to achieve high data rates of between 110 and 480 Mbps over short ranges of less than 10 meters. Since very high or unpractical antennas are required in radio link budget of system. MIMO is the key to high rate wireless communications. In the 5 GHz and 60 GHz MIMO channels, tests were performed for determining data rate, range and configurations. In the 5 GHz MIMO channel both the minimum and maximum configurations are determined for supporting 54-600 Mbps rate and up to 200 m range. In the 60 GHz MIMO channel, configurations are determined for achieving gigabit and multigigabit capacities with less than 10 m ranges. Results are also compared with experimental measurement data in order to provide reliable parameters and useful information for system development and standardization groups.