The Communication System of Building from Outdoor to Indoor with AMC at 10 GHz

The propagation model of communication systems was used Propagation from outdoor to indoor building. On the inside, that building used partition with brick. That propagation condition used downlink condition from the mobile station side. The communication frequency used 10 GHz. Some parameter variation was used in this research, such as radio base station coverage, mobile station location of the building, and code rate communication. The coverage variation of radio base stations used femtocell and picocell as a result described signal to noise ratio (SNR) at every node communication, adaptive modulation and coding (AMC) variation, and coverage area percentage in the building. AMC was used for adaptation MCS at the communication. The modulation and coding scheme (MCS) was used, consist of QPSK, 16 QAM, and 64 QAM.


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Jurnal Infotel Vol. 12  adaptive modulation and coding (AMC). Frequency communication used 10 GHz. That frequency was influenced by atmospheric attenuation such as oxygen and water vapor. The coverage variation of radio base station (RBS) used femtocell and picocell. The mobile station was located with a distance variation on every floor in the building. The partition at every room was used by brick. The Propagation of communication systems was influenced by the permeability of brick. As a result, was described adjustment of AMC at communication, signal to noise ratio (SNR), and coverage area percentage. Modulation and coding scheme (MCS) were based on threshold modulation value. That modulation and coding scheme was used for AMC. Modulation and coding scheme was used consist of QPSK, 16 QAM, and 64 QAM. The research was related to this research, such as AMC around the buildin g environment for the mobile station communication a t the train [21].
The propagation communication was influenced by atmospheric attenuation and brick permeability attenuation. The communication frequency used 10 GHz. RBS femtocell was located outdoor, and the mobile station was placed indoor. The variation of the mobile location station was placed in every brick partition. The diffraction mechanism was propagated from the transmitter to the receiver. That diffraction mechanism was modeled with a single knife-ed ge method.

A. Environment Model
The transmitter location existed at outdoor in the building. The RBS coverage variation was used, consist of femtocell and picocell. RB S was placed near the street with a high of 30 meters, showed in Fig.1. That figure was showed the communication propagation from the transmitter to the receiver inside the building. The mobile station was showed with a node at every brick partition and every floor. The diffraction mechanism was caused by the building. The diffraction was modeled by a single knife-ed ge method [22]. The detail of a sin gle knife-edge method was shown in Fig. 2 [21].

B. Knife-Edge
The equation for a single knife-edge method could be seen in equation (1). v parameter was represented as Fresnel Kirchoff [22]. λ parameter was represented as long wave (m), h parameter was represented as high of diffraction (meter), d1 parameter was represented as transmitter distance through the node (meter), and d2 parameter was represented as receiver distance through the node (meter). Figure 3 was showed communication propagation in the first buildin g. That building was used three floors. Every floor was available in rooms. That room was a partition with brick. That brick was used permeability of 3,4.
The communication system from outdoor to indoor at another the build ing was showed in Fig. 4. The second building was modeled with more partition and more floor than the first building. SNR value was shown in equation (2). The transmitter power of femtocell was used 14 dBm. s parameter was signal value, N was noise power, and SNR value was signal to noise ratio [22].
N parameter, as shown in equation (3). K parameter was Boltzman constant, B parameter was bandwidth, F parameter was noise figure, T parameter was standard noise temperature (290 o K) [22]. F value was used 5 dB for LTE, and B value was used 3 MHz of OFDM (Orthogonal Frequency Division Multiplexing) [23].
The attenuations of communication were caused by atmospheric attenuation and material permeability attenuation.
Atmospheric attenuations were influenced by oxygen, and water vapor could be observed at equation (4) [24]. and parameter was described gaseous attenuation, and path length (km).

= (4)
The AMC process was based on a modulation and coding scheme (MCS). MCS has used, such as QPSK, 16 QAM , and 64 QAM [25]. Modulation of QPSK has used some code rates consist of 1/8, 1/5. 1/4, 1/3, 1/2, 2/3, 3/4, and 4/5. Modulation of 16 QAM was used; some code rates consist of 1/2, 2/3, 3/4, and 4/5. Modulation of 64 QAM was used; some code rates consist of 2/3, 3/4, and 4/5. The AMC process at communication propagation was based on threshold modulation and coding schemes.  The first build ing was used three floors. The second buildin g was used five floors. Every floor in the first buildin g was used five partitions, and the second building at every floor was used three partitions. That partition used bricks. Some data was obtained at the first build ing, such as the second floor at the first partition with a distance of 222.63 meters and AMC of 16 Fig. 8 showed AMC from the modulation and coding scheme for picocell at the buildings. That figure showed the communication propagation for two buildings when communication was used picocell. Some data was obtained at the first building, such as on the second floor of the first partition with a distance of 222.63 meters and AMC of 64 QAM code rate 4/5 obtained SNR 21.08 dB, and the third partition with a distance of 322.59 meters obtained SNR -22.40 dB. The third f loor of the first partition with a distance of 222.09 meters and AMC of 64 QAM code rate 4/5 obtained SNR 21.1 dB, and the third partition with a distance of 322.05 meters and AMC of 16 QAM code rate 1/2 obtained SNR 11.07 dB. Some data was obtained at the second building such as at the second floor of the first partition with a distance of 396.82 meters and AMC of 64 QAM code rate 2/3 obtained SNR 16.06 dB, and the third partition with a distance of 496.77 meters and AMC of QPSK code rate 4/5 obtained SNR 7.3 dB. The third floor of the first partition with a distance of 396.57 meters and AMC of 16 QAM code rate ½ obtained SNR 8.63 dB, and the third partition with a distance of 496.52 meters and AMC of QPSK code rate 4/5 obtained SNR 7.3 dB. Figure 9 showed the percentage of coverage area in the second building with femtocell and picocell. That figure described the percentage of coverage area on the first floor less tha n other floors. That effect was caused by diffraction through the building. Diffraction at this research was modeled with a single knife-edge method. The percentage of the coverage area for femtocell was consist of the first build ing of the second floor obtained 40%, and the third floor obtained 80%, the second building of the second floor obtained 100%, and the third floor obtained 100%. The percentage of the coverage area for picocell was consist of the first building of the second floor obtained 40%, and the third floor obtained 100%, the second building of the second floor obtained 100%, and the third floor obtained 100%.

IV. DISCUSSION
This sect ion described the discussion from the research result. This research analyzed the communication of buildin g from outdoor to indoor. Every partition was caused by the permeability of brick. The coverage communication was used femtocell and picocell. The communication model has used the buildin g environment so that the propagation method for obstacle was used as a single knife-edge method. AMC process was based on MCS, such as QPSK, 16 QAM, and 64 QAM. The higher location of the mobile station was placed in the inside building but still lower than the radio base station location so that the SNR value will be increase. The condition coverage at the radio base station was used, such as femtocell and picocell. Some data was obtained for femtocell condition at the first building, such as the second floor of the first partition with 16 QAM code rate 2/3 obtained SNR 12.08 dB. The third partition obtained -31.41 dB, the third floor of the first Jurnal Infotel Vol. 12  V. CONCLUSION This sect ion was described the research conclusion about communication systems of building from outdoor to indoor with AMC at 10 GHz. That frequency was influenced by atmospheric attenuation. The Propagation through the building was an obstacle with brick permeability at every partition in the inside building. That obstacle was caused by a diffraction mechanism. That diffraction modeled by a single knife-edge method. The cell variation used picocell and femtocell. SNR value obtained picocell h igher than femtocell. The more elevated location of the mobile station at the building but still lo wer than the radio base station location, so the SNR will be increased. The decrease of SNR was caused by brick partition attenuation and communication diffraction. AMC process used modulation and coding scheme with a high threshold such as femtocell of 16 QAM code rate 2/3, and picocell 64 QAM code rate 4/5. The nearer the MS loca tion, the higher the MCS variation was used. Further research development such as SIMO, MISO, MIMO.