Measurement-Based Evaluation of Spectral Efficiencies in Outdoor-Indoor Multiuser MISO Systems in Femto-Cells

Abstract

Based on measurements for a street-canyon-type femto-cell we compare the downlink spectral efficiencies of various intra-cell interference mitigation systems. This includes Zero-Forcing (ZF), Regularized Zero-Forcing (RZF) and DirtyPaper Coding (DPC). As a reference for comparison we consider subsectorization and TDMA. Out-of-cell interference, treated as additive Gaussian noise, is included in two modes: a) all cells transmit simultaneously and b) neighboring cells transmit in alternated time slots. We find that ZF, RZF and DPC can offer increases in spectral efficiency over subsectorization and TDMA by factors of around 4 under interference-limited conditions. This contrasts with estimated gains of only around 2 when using a standard 3GPP mode instead of our measured data. This difference is due to the greater inter-cell isolation that characterizes our street-canyon-type test environment. We find that RZF achieves over 80% of the DPC's spectral efficiency under virtually all operating conditions.

Empirical Rates Characterization of Wearable Multi-Antenna Terminals for First-Responders

“…The channel sounder uses the procedure described in [20] to measure the complex path-gains that form the MIMO channel matrix for each of the L = 72 radio links (each corresponding to a different relative position of the transmitter and receiver). The transmitter is continuously transmitting a 14.4 dBm wave carrier at 3.5 GHz.…”

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“…RBS memiliki cakupan yang berbeda-beda, seperti macro cell, micro cell, pico cell, dan femtocell. Beberapa penelitian berhubungan dengan cells diantaranya tentang skema pengalokasian cognitive LTE-A menggunakan femtocells [5], propagasi model path loss untuk menganalisa pico dan femtocells [6], dan penelitian tentang evaluasi efisiensi spectral di luar dan di dalam ruangan dengan sistem MISO pada femtocells [7]. Variasi ketinggian RBS femtocell digunakan untuk mengetahui perbedaan hasil dari sistem komunikasi seperti nilai SNR, dan persentase daerah tercakup hasil komunikasi.…”

“…Sehingga pemodelan ketinggian RBS femtocell setara dengan ketinggian tiang lampu jalan. Sedangkan tiang lampu jalan memiliki ketinggian yang didasarkan dari spesifikasi penerangan jalan pada daerah perkotaan menurut Standar Nasional Indonesia (SNI) [7]. Sesuai dengan spesifikasi penerangan jalan tersebut maka ketinggian tiang lampu jalan yang digunakan diantaranya 6 meter, 8 meter, dan 10 meter.…”

Feasibility of a wearable textile antenna hub based on massive MIMO systems

“…Its geometry follows N h = 2 columns in the horizontal plane and N v = 6 antenna rows in the vertical plane. Then, the total array size is N The channel sounder uses the procedure described in [72] to measure the complex pathgains that form the MIMO channel matrix for each of the L = 72 radio links (each corresponding to a different relative position of the transmitter and receiver). The carrier frequency is down-converted to baseband by the 4-channel receiver, giving rise to outputs at 10 kHz that are sampled at 2×10 5 samples/s by a data acquisition card for 1 second.…”

“…Then, keeping in mind the explained above, the measured MIMO channel matrices are obtained by combining the captured SIMO channels. Concretely, in this work72 …”