Exchange of information between devices. Communication can be wired or wireless.

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2answers
52 views

Address and communicate with multiple devices in a matrix

I have a large matrix of devices, "nodes", that I would like to address and communicate with - assume > 50 nodes. Each of the nodes have a controller that receives data from a central microcontroller ...
0
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1answer
28 views

How to find the fundamental frequency and present harmonics from a graph?

I'm having a very hard time understanding frequency and harmonics and now that I'm working on problems, I am completely perplexed. The problem reads as follows - Assume that string of bits ...
0
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1answer
81 views

Finding the power output when one single sideband at m=0.4 is transmitted together with the carrier component which is reduced by 26dB

Question An AM transmitter has an output of 24kW when modulated to a depth of 100%. Determine the power output from first principles when one single sideband at m=0.4 is transmitted together ...
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1answer
91 views

Daisy Chaining ADC Sensors

I'm creating a grid of 200+ pressure sensors and need a clean way to get their values back to the master controller without a mess of wires. To me it seems like daisy chaining all the sensors ...
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2answers
133 views

Double Side-band Amplitude for Radio Transmission & Single Side-band Reduce Carrier for Point-to-point Transmission

What are the reasons which lead to the use of double side-band amplitude for radio transmission, and single side-band reduce carrier working for point to point transmission? Thank you for your help.
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2answers
64 views

communication 101 [closed]

I have a couple of really basic questions. (1) When a device(Device 1) communicates to another device(Device 2), do the devices have to operate in the SAME frequency for the data transmission to take ...
1
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0answers
47 views

Which communication protocol to use [closed]

Consider two devices having a basic radio transceiver (and use the same frequency) and a base station which uses a different frequency radio. The data from base station should be broadcasted to both ...
0
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2answers
59 views

Why is the data rate a function of the length of the transmission line?

The length of a transmission line is limiting the highest possible data rate on that line. Why are faster signals more likely to become corrupted on long transmission lines than on shorter ones, with ...
1
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0answers
77 views

Why is “throughput” called “bandwidth”?

But back in school, I had learned that the "bandwidth" of a communication channel is the frequency of the highest-frequency signal minus that of the lowest-frequency signal that it can carry. Yet in ...
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1answer
114 views

Why AM is preferred over FM in long distance communication?

In almost all long distance communication AM is preferred over FM. Do type of modulation has anything to do with this or it is just depending on transmitting frequency?
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0answers
57 views

Ethernet communication [closed]

I want to make a simple program which achieves Ethernet communication. Specially I will try to connect this ENC28J60 Ethernet LAN Network Module and make a simple real time monitoring application ...
-7
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1answer
84 views

Signal jammer circuit design [closed]

This is a circut for a jammer for the 450Mhz , but my calculation says it's for 277Mhz. If I want to prepare for a gsm 900 , what changes would I have to make .
0
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1answer
81 views

Two arduino unit communication

OK plain and simple I'm not sure to use IR or RF. This is short distance up to maybe 10 ft. I have an Arduino Uno that I have all set up here. I press a button and it carries out its code. This is ...
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2answers
75 views

Amplitude modulation of unit step signal

What will be the amplitude modulated signal, if the input is an unit step signal? You can take any carrier signal (though I would recommend sine wave) and take any carrier frequency because that is ...
1
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1answer
44 views

Beagleboard USB Packet sniffer

I had picked up a beagleboard a few weeks ago and had then looked into the USB sniffer project that had been created a while back. (https://gitorious.org/beagleboard-usbsniffer/) I understand that ...
2
votes
2answers
49 views

Trying to Understand Spurious Sideband Interference (and some causality problems…)

Suppose I have a radio and I intend to transmit a 0.1 µs pulse on a 100 MHz carrier. Fourier theory tells me that this signal will produce some sideband interference resembling a Sinc function. ...
0
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2answers
80 views

Pictures of different adapters, trying to understand how they work (PLC to PC communication)

I purchased the blue adapter in the picture as a USB/RS232 converter. It takes in the RJ12 cable from my PLC, and converts it to a USB input. Now when I try to use an RJ12-DB9 Female and then connect ...
1
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1answer
78 views

How does USB 3.0 negotiate power states?

I noticed, in another question, a comment regarding USB power states. I know that USB 2.0 negotiated power by tying the D+ and D- lines to specific voltages but I can't seem to find any information ...
0
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1answer
80 views

Can I transmit data over RJ12 to a PC from a PLC?

I have a Click PLC which has two RJ12 ports. I have successfully programmed it using C# and nModBus as a slave, but now I want to test the PLC as a master and the PC as a slave and noticed my laptop ...
0
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4answers
93 views

Slowest transmission speed supported by TOSLINK TX and RX?

I'm writing an Arduino communication library that uses differential Manchester coding (see: http://forum.arduino.cc/index.php?topic=257985.0). I'm wondering how to communicate between two Arduinos ...
1
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1answer
69 views

Shannon versus Nyquist bit rate calculations

I am confused with the shannon channel capacity formula Versus nyquist bit rate. nyquist formula contains signal levels while Shannon formula doen't, how to refer to signal Levels in shannon's ...
0
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0answers
13 views

How do Coherence Time and Coherence Bandwidth influence the decision on the diversity scheme?

I came across a statement in a lecture slide which states: Coherence Bandwidth and Coherence Time govern our decisions about the diversity scheme that we would choose The lecture is in the field ...
2
votes
3answers
118 views

What happens if SINR is < 1?

What happens if the SINR of a signal is less than 1 in a (wireless) network? Is that practical at all to have a SINR < 1? Using the Shannon capacity formula, it seems that we must be able to have ...
0
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1answer
60 views

Check me on this modulation question?

I need to check my answers for parts (a) and (c); a) I got q(t) = p(t)cos(5pit) c) i got y(t) as a rectangle with amplitude 1 from -pi to pi. So, y(t) = 1/8 f(t) Am I correct for both parts;
3
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1answer
72 views

AVR - ATmega16 - Timer config

Trying to figure out the timer setup in Atmel Studio 6 for an ATmega16 microcontroller. And I just don't get it. I am trying to create a TickCount similar to GetTickCount() Retrieves the number of ...
1
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1answer
54 views

Bandwidth of CW modulation (morse code)? [duplicate]

How can I relate the bandwidth required by a morse code signal over RF to: the length of a dash, and the length of a dot the time between dots and dashes the speed of keying? Are all applicable to ...
2
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0answers
98 views

What is bit-true implementation

What is bit-true implementation (with an example if possible)? I was reading a paper and it was stated "a bit-true implementation of the algorithm on a FPGA was performed." So what exactly is ...
2
votes
2answers
159 views

Signal rate, data rate and bandwidth in digital signals

I'm trying to understand the concept of signal rate and the relation between signal (baud) rate and bandwidth of digital signals from a book about data communication. First, the book distinguishes ...
3
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2answers
411 views

Bandwidth for a single tone

If I am using a channel only for morse code (CW), with one frequency and interruptions for dots and dashes, is the necessary bandwidth of the channel twice the audio frequency of the tone used for CW? ...
3
votes
1answer
75 views

Bluetooth low energy communication

I was wondering if it is possible to communicate between 2 BLE devices when one is placed inside the car and another placed outside the car. Can BLE communicate in such a scenario? For example, I ...
0
votes
2answers
42 views

the response of wireless channel to an input

I am reading the wireless of David Tse. In the 2nd chapter of this book there is a discussion about the response of the channel due to an input. It has said that since the channel is linear its output ...
2
votes
1answer
132 views

What's the maximum CAN bus frame (message) rate at 125 kbit/s?

My CAN bus is running at 125 kbit/s and is using extended frame format exclusively. I would like to know what's the maximum rate of CAN frame I can send out. Suppose the data length is always ...
1
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2answers
87 views

Explain Rayleigh Fading in plain English

For a couple of days I am trying to understand the Rayleigh Fading model, but I am failing to. I look at various articles and tutorials online, everything goes fine up to a points, but then a lot of ...
0
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0answers
92 views

Read and write FPGA registers via USB or Ethernet

I'm working on an FPGA project on an Atlys Spartan 6 board. I'm programming it in VHDL. I have two 32 bit registers, one for output, the other for input. I need to be able to, respectively, read and ...
2
votes
2answers
230 views

GPRS data call using GSM/GPRS modem (Siemens TC35 and/or MC35)

I'm developing a data aquisition module, that amongst other things, it have to comunicate through GSM/GPRS module, since it will be a mobile application. I can connect to the module and send sms's ...
1
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1answer
46 views

What happen if 0 and 1 are transmitted simultaneously with BPSK?

I'm just curious that what happen if 0 and 1 are transmitted simultaneously from different source nodes to an equidistant destination node with BPSK? Assuming perfect signal shaping, synchronization ...
0
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1answer
58 views

frequency allocation for telecommunication companies

For a high bit rate in data communication we need a high bandwidth. Suppose there are hundreds of carriers in a particular region and they are all allocated microwave frequencies. Minimum spacing ...
1
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1answer
76 views

Quantization levels and SNR

Im' trying to build a big picture of telecommunication and i'm stuck in a topic, related to digital communication. But the problem is that i can't go too deep into the topic because it is imensely ...
1
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3answers
153 views

How do you achieve an efficiency of more than 1 bit per Hertz?

I believe this is also known as spectral efficiency - apparently it's possible for us to transmit more than one bit per Hertz. But to my layman mind I imagine a Hertz being only capable of ...
1
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1answer
39 views

Real Time Data Capture System

I would like to build a system which could capture an analogue waveform data in real time. For the basic data acquisition system I can use an ADC to digitise an analogue waveform and store this in a ...
2
votes
1answer
67 views

Wireless telecom system (cellular with Erlang and spectral efficiency)

We have a spectrum of 20MHz that we will use on a wireless cellular system, which requires 50kHz per channel. The system is using cluster size K = 4 and the radius of every cell is R = 1 km. a) ...
0
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0answers
26 views

Calculating Eb/No for a desired Pe for a matched filter

can someone verify that I am doing this right. I have been given the question: In most applications, communication systems are designed to have a Pe of 3E-5 or less. Find the minimum Eb/No required ...
1
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1answer
67 views

Calculating the output power from an Amplifier

This is not based on any particular hardware. I am trying to understand the theory behind it by doing tutorial questions from my uni, I have completed the question but don't understand the approach ...
1
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1answer
143 views

What is the 'best' way of communicating with small microcontrollers/devices?

var best = "simple & cheap"; I have a server in my apartment that I have an XBEE hooked up to. I use it to communicate with another XBEE plugged into an Arduino. I am trying to hook up many ...
1
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0answers
54 views

Definition of “hot” resistor when calculating RMS thermal voltage?

I am calculating the RMS thermal noise voltage of a "hot" resistor of a tutorial sheet for uni. I have used the standard Johnson–Nyquist formulas, but the answer sheet does not include the entire ...
1
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1answer
86 views

Xbee configuration with X-CTU on linux

I'm trying to configure an XBee with the X-CTU tool using Wine. I followed the steps given in this tutorial. I plug the USB in and check the kernel logs to see on which serial devices it has been ...
0
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2answers
54 views

How does Signal-Noise-Ratio related to receiver power

If I have the instaneous Signal-Noise-Ratio (of the receiver), but no other information, and I am interested in the instaneous \$\mathbf{Power_{received}}\$, is there any relationship between these ...
1
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0answers
70 views

How to calculate Input backoff per carrier of a satellite

I was trying to calculate the sizing of SSPA in my satcom network where input backoff per carrier is required to calculate Power flux density. My current network configuration in C band is Total ...
0
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1answer
54 views

Cell in Cellular communication

When they talk about the "cell" in cellular communication, they often refer to the shape of hexagon. If I am correct, this is probably the coverage area of the transmission base tower. SHouldn't be ...
0
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3answers
92 views

Long distance communication

I am looking for a cheap single wired solution to transfer data of some sensors connected to a uC over a distance of 1 KM from a control room on UART. The data is of 16 bytes, no high speed ...