, and 37.1 GHz for the LOS and NLOS cases. Regression analysis is applied to the mea- surement data by using the CI and ABG models [7,8]. A summary of these regression results is shown in Table 11.1. The CI model is expressed as PL(d) = 10nlog10(d) + FSPL(f, + Xo (11.1) FSPL(f, = 32.44+20log(fc)+20log(d) (11.2) 11 Measurements Table 11.1 Regression analysis. Parameters o SF (dB) Table 11.2 Channel sounder specifications. Center frequency 19.85 GHz Bandwidth 50 MHz Transmission signal Number of subcarriers Transmission power 30 dBm Tx antenna Sleeve (2.4 dBi) Rx antenna (19.1 dBi: 20 deg. HPBW) where PL is the path loss in dB, d is the distance from the BS to the MS in meters, f is the frequency in GHz, and Xo is the shadow fading factor in dB, which is the log-normal distribution with the standard variation of OSF. The ABG model is expressed as PL(d) = 10alog10(d) + B + 10ylog + Xo (11.3) 11.2.2.2 Measurement of Channel Model Parameters Table 11.2 gives the specifications for the channel sounder for the 20 GHz band. On the transmitter (Tx) side, Orthogonal Frequency-Division Multiplexing (OFDM) signals with a 50 MHz bandwidth at the 20 GHz band are generated and transmitted from a 2.4 dBi sleeve antenna. The transmission power is 30 dBm. On the receiver (Rx) side, a 19.1 dBi horn antenna with a 20° half-power beamwidth (HPBW) is used. After down-converting the received radio frequency (RF) signals to an intermediate frequency (IF) band, the complex amplitudes of the subcarriers (transfer functions) stored in a PC. The power delay profiles (PDPs) are obtained by converting the stored data into channel impulse responses. Measurements were conducted in the campus of Niigata University, Japan [9]. Figure 11.15 shows the measurement environment. The Rx (emulating a BS) was set on the rooftop of building BO at position BSO. The Tx (emulating a mobile station) was set on the rooftop of a car at points MS1-MS6. The condition between the Tx and the Rx was LOS. The antenna heights of the Rx and the Tx were 11.5 and 2.5 m, 