Licensed-assisted access (LAA) is a 3GPP enhancement of Long-Term Evolution (LTE) to allow cellular network operators to offload some of their data traffic by accessing the unlicensed 5 GHz frequency band, which has been standardized in LTE Release 13 only for the downlink (DL). LTE LAA allows operators to transmit in the unlicensed spectrum using … Read more
A LTE repeater (also known as cell phone signal booster or amplifier) is a type of bi-directional amplifier used to improve UE reception and address coverage issues. LTE repeater does not just do power amplification of the received signal from LTE eNB or LTE Base Station, it also selects the band specific signals using one duplexer. After amplification it transmits the signal back to … Read more
What is Inter Symbol Interference (ISI) ? In an ideal system (theoretical), the transmitted symbols arrive at the receiver without any loss or interference, as shown in the following figure. But in a real scenario, due to the signal propagation phenomena, such as reflection, diffraction or multipath, a receiver can receive several delayed versions of … Read more
It was last year when I first read/ discovered about 802.11ax on one of the websites mentioned below as references. Ever since I tried to collect more information and wanted to write about the same. But every passing day/ week/ month, I learnt a new aspect about 802.11ax. Being from Telecom Industry and Radio background, … Read more
Reference Signal Received Power RSRP is the linear average of reference signal power (in Watts) measured over a specified bandwidth (in number of REs). This is the most important measurement UE has to do for cell selection, re-selection and handover. It is very similar to CPICH RSCP in WCDMA. It is applicable while UE in different RRC states … Read more
RSSI represents the total received wide-band power measured over entire bandwidth by UE. RSSI is not reported to eNodeB. It is computed to be used for the calculation of RSRQ in LTE system. RSSI is also a power and its measurement unit is dBm same as RSRP. RSSI=Serving Cell Power + Neighbour Co-Channel Cells Power + … Read more
RSRQ is th Reference Signal Received Quality and it can be defined using following. RSRQ= (N* RSRP)/RSSI As per the definition of RSSI, It is wide band power including signal power from serving cell, co-channel neighbour cell, interference from other cell interference and noise, in similar word one can say that RSRQ define the purity … Read more
SNIR is a measure of Signal Quantity and Interference and Noise Quantity and it is very important measurement in terms of RF and sometime it is also called as SNR in absence of interference. It indicate how much desired signal is stronger compare to Noise and interference. Its unit is dB.Mathematical it can be express … Read more
LTE System support for flexible bandwidth like 1.4 MHz, 3 MHz ,5 MHz,10 MHz , 15 and 20 MHz and this bandwidth is the major contributor system capacity. There are some other parameter which affect the system capacity of an LTE eNodeB and given below Channel Bandwidth MIMO Antenna Configuration Modulation Coding Scheme UE radio Condition … Read more
Long Term Evolution (LTE) supports both FDD and TDD Duplex mode. The major difference in TDD and FDD is that in TDD system a single frequency is shared in time domain between Uplink and Downlink where as in FDD separate frequencies are used for Uplink and Downlink transmission. A TDD frame structure is shown in … Read more