Experimental comparison between centimeter‐ and millimeter‐wave ultrawideband radio channels

Abstract

This paper analyzes radio wave propagation phenomena at two very different frequency bands: 2-10 GHz (centimeter wave) and 57-66 GHz (millimeter wave (mm-W)). The two frequency bands have been measured using the same equipment and under similar propagation conditions, such as path loss, root-mean-square delay spread, maximum excess delay, and Rician K factor, and their respective correlations compared. Obstructed line of sight situations have also been considered by using metal and cardboard obstructions. The statistical distributions, main specular reflections, and decay factors have been found similar for the two bands. However, the measured path loss, correlation in terms of electrical distances, and the K factor are higher for the millimeter-wave frequency band. Indeed, the importance of propagation mechanism changes from one band to the other, which must be considered in the design of future mm-W systems.

Measurement and Analysis of Channel Characteristics in Reflective Environments at 3.6 GHz and 14.6 GHz

“…The "path loss exponent" in Table 2 indicates a minimal difference in the path loss exponent for the two frequency bands. This observation is in line with what was experienced in [8,10,28]. In [8], a multi-frequency (0.8 GHz to 28 GHz) path loss model for external wall attenuation and indoor propagation was presented.…”

“…For the indoor propagation, the measurement results show that the linear attenuation factor (similar to the path loss exponent) is not very sensitive to the frequency. In [10], the measured path loss exponents are 1.31 and 1.29 for centimeter-and millimeterwave ultra-wideband LOS channels, respectively. In [28], the exponents are similar at 1.33 and 1.31 for 5 and 60 GHz for indoor channels.…”

“…However, some papers present different results. For example, in [10], for LOS, the RMS delay spread is around 8 and 4 ns for 2-10 and 57-66 GHz, respectively. The measurements were performed in a laboratory furnished with several closets, shelves, desk, and chairs.…”

Channel Models and Beamforming at Millimeter-Wave Frequency Bands

“…A seminal work [188] mentions that a basic propagation mechanism of the measured 40 and 60 GHz outdoor channels is similar, while the fading statistics are different from microwave mobile links due to fewer multipaths. Reported comparisons of channel characteristics at the mm-wave bands cover pathloss and delay spread with those measured at 2 GHz in office rooms [189], [190], 5 GHz in halls and meeting rooms [191], [192], 6.5 GHz in a car compartment [62], 17 GHz in an office building [193], [194] and in a car compartment [195], and finally with ultrawideband indoor channels [196], [197]. Comparison of channel characteristics parameters for different mm-wave frequency bands is reported in [27] for outdoor 38 and 60 GHz channels, [90] for indoor 60 and 70 GHz channels, and [21], [28] for 28 and 73 GHz in urban cellular channels.…”

Experimental Investigation of Electromagnetic Reverberation Characteristics as a Function of UWB Frequencies

“…1b) are used for the validation of the developed model (see section IV). The measurement scenarios and the channel sounder settings can be found in [16] but the main settings are recalled here for the reader: i) the frequency is ranging between 2 and 10 GHz with 2048 frequency points and ii) three transmitter (Tx) blocks were considered. Each block consists of 95 Tx positions along a linear segment of 95 cm, whereas the receiver (Rx) occupied 8 positions along a linear segment of 70 cm (see Fig.…”