Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [lte]

LTE - Long Term Evolution - is a wireless cellular system

LTE - Long Term Evolution - is a wireless cellular system. It uses OFDMA for multiple access, unlike 3G cellular that was based on wideband CDMA. Unlike earlier generations of cellular systems, whose primary focus was on voice services, LTE is primarily designed for data services. It has an all-IP core network.

Use this to tag questions that relate to LTE.

33 questions
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Why are there two LTE antennas?

I have a design with LTE CAT 4 and I wonder why two antennas are needed. I searched around the web but am still kind of confused. Below are my questions: Is the second antenna used for Rx only? Is LTE modem trying to select which antenna gives…
jsmith0910
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Impedance matching through via and signal trace of 2 layer board

Due to tight space constraints I need to pass my LTE signal (800-1800 MHz) through a via. The proximity between the antenna connector and the modem is very short (literally on the other side of the pad). Using impedance calculators, I have found…
Troy Cados
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Calculate power of an LTE Signal

I am looking for the formula to convert the power level of an OFDM RF signal to an absolute power level. For example if I have my typical rectangular RF spectrum and the bandwidth of the signal is 10MHz, if my signal power needs to be 23dBm, what…
Eoin O Connell
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How do LTE radio networks deal with co-channel interference?

In 802.11 Wifi, I've read that a wifi adapter (like my laptop's wifi adapter/radio) will use Energy Detection to see if a channel is busy (if a certain energy threshold is detected on the channel, it won't try to use the channel itself). Then there…
Jerry Ku
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What type of antenna connector is this? (USB 4G modem)

What type of antenna connector is in the Huawei E5573Cs-322 phone? (Internally - left side on the image) SMA or ts-9? Photo attached.
Ruslan Korolev
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Can the PA1616D GPS module connect to a backend server to send GPS updates to a mobile phone?

I am building an IOT device that will be moving around outdoors and will not be able to have a secure wifi connection. I want to be able to know the location of this device at all times on my mobile phone, so I am using a PA1616D to be able to get…
Trev347
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How to build a safe antenna switch and how to simulate loss of reception?

Problem : I'd like to run the following test routine with an LTE router: cause a loss of signal, as if the router entered a tunnel remove the signal obstruction, as if the router just exited said tunnel check how the router behaves after the signal…
jwav
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LTE PC5 Subframe Structure

LTE provides sidelink communication via the PC5 interface. According to the "secondary literature" [1],[2],[3], the PC5 subframe is structured as follows: Symbol 0,1,3,4,6,7,9,10,12: PSCCH, PSSCH (Primary Sidelink Control / Shared Channel Symbol 2,…
EMC
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Coexistence Testing for Consumer grade RF and ECG Systems

How are ECG (electrocardiogram) systems tested on wearable products to show no coexistence issue RF systems? Specifically I am trying to understand if the products are tested with ECG electrodes terminated in some way or not? It seems to me that the…
EasyOhm
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Not getting expected band pass filter response

I am trying to make a LTE signal repeater and trying to filter all other signals except the band 3 (869 - 894 MHz) This is what I am getting: This is the circuit: Any suggestions on improving the filter and how can I use standard value components…
Prabodh
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How are LAN routers, WAN routers and eNodeBs connected to each other (TCP/IP)?

I'm new to telecommunication, and from what I understand, an user equipement is either connected to a LAN router or an eNodeB, and a LAN router is connected to a WAN router, and routers send the packets to the correct destination with a routing…
qwerty_99
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Does data rate depends on Frequency not on BW?

If we have two RF signals of 900Mhz and 1800Mhz both of equal Bandwidth 20Mhz which one has higher data rate?
Shashank
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Current waveform for LTE transmit

I am designing an IoT system which uses the SIM7000A. In the SIM7000 series datasheet it says that the highest possible current for LTE is under 200mA (section 5.4 of SIM7000 Hardware Design_V1.03). However, it provides no other information - like…
Bill Mahoney
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Is NB-IoT roaming possible?

I found a comment on a blog post stating that NB-IoT doesn't support roaming: nbiot do not support roaming (you must have sim from the operator that have the infrastructure). nbiot also lacks support for handover (you can not maintain connection…
DurandA
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How to connect CPU with RGMII pins to an LTE module that takes only SGMII signals?

The Hi3519 Hisilicon CPU has RGMII pins. We are trying to connect it to the EC21 LTE Module from Quectel which contains SGMII pins. Would using two Realtek RTL8201F-VB-GG PHY chips with magnetics between them work as shown below? EC21 (SGMII pins)…
k051819
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