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Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems

Obinna O., Kennedy O., Osemwegie O., Nsikan N.

International Journal of Electronics and Telecommunications

2017

Vol. 63, No. 3

299--304

The ever-growing need for high data rate, bandwidth efficiency, reliability, less complexity and less power consumption in our communication systems is on the increase. Modern techniques have to be developed and put in place to meet these requirements. Research has shown, that compared to conventional Single Input Single Output (SISO) systems, Multiple-Input Single Output (MISO), and Multiple-Input Multiple-Output (MIMO) can actually increase the data rate of a communication system, without actually requiring more transmit power or bandwidth. This paper aims at the investigation of the existing channel estimation techniques. Based on the pilot arrangement, the block type and comb type are compared, employing the Least Square estimation (L.S) and Minimum Mean Squared Error (MMSE) estimators. Pilots occupy bandwidth, minimizing the number of pilots used to estimate the channel, in order to allow for more bandwidth utilization for data transmission, without compromising the accuracy of the estimates is taken into consideration. Various channel interpolation techniques and pilot-data insertion ratio are investigated, simulated and compared, to determine the best performance technique with less complexity and minimum power consumption. As performance measures, the Mean Squared Error (MSE) and Bit Error Rate (BER) as a function of Signal to Noise power Ratio (SNR) of the different channel estimation techniques are plotted, in order to identify the technique with the most optimal performance. The complexity and energy efficiency of the techniques are also investigated. The system modelling and simulations are carried out using Matlab simulation package. The MIMO gives the optimum performance, followed by the MISO and SISO. This is as a result of the diversity and multiplexing gain experienced in the multiple antenna techniques using the STBC.

Throughput physical layer analysis of LTE

Reznikov M., Olszewski S., Al-Shuraifi Talib M., Al-Zayadi H., Komada P.

Elektronika : konstrukcje, technologie, zastosowania

2013

Vol. 54, nr 8

63-66

Technologia Long Term Evolution (LTE) Wyd. 8 zapewnia wysoką szybkość transmisji danych szczytowych na poziomie 300 Mbps w dół strumienia (ang. Downlink) i 75 Mbps w górę strumienia (ang. Uplink) dla częstotliwości 20 MHz. Artykuł dotyczy badania, maksymalnej przepustowości łącza w dół oraz w górę strumienia, w zależności od scenariusza względem warstwy fizycznej. W pracy, obliczenia przepustowości zostały przeprowadzone wyłącznie kanałów danych PUSCH (Physical Kanał Share Uplink) i PDSCH (Physical Downlink Share Channel) z uwzględnieniem metody dostępu zarówno częstotliwościowej FDD (Frequency Division Duplex), jak i czasowej TDD (Time Division Duplex). Analiza przepustowości, różnych elementów zasobów, przypisanych do odpowiednich kanałów danych: downlink i uplink została przeprowadzonoa dla FDD i TDD przy różnych warunkach. Przy czym elementy w dół strumienia (downlink), w ramach FDD zostały obliczone dla wszystkich możliwych pasm systemowych (1,4 MHz do 20 MHz) oraz portów anteny. W artykule zamieszczono rezultaty przeprowadzonej analizy warstwy fizycznej technologii LTE.

Long Term Evolution (LTE) Release 8 provides high peak data rates of 300 Mbps on the downlink and 75 Mbps on uplink for 20 MHz bandwidth. In this study, the maximum throughput of downlink and uplink transmission is investigated depending on scenario for the physical layer. In this paper the throughput calculation exclusively contains data channels (Physical Uplink Share Channel (PUSCH) and Physical Downlink Share Channel (PDSCH)) for both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) operations. For throughput analysis, different resource elements that are assigned for data channels of downlink and uplink are calculated for FDD and TDD operations in different conditions. FDD downlink resource elements are calculated for all the possible system bandwidths (1.4 MHz to 20 MHz) and antenna ports. These results of throughput physical layer analysis of LTE are presented in this paper.