Broadband Digital Communications

Error rate: Is the rate at which packets (bits) incur errors in transmission (ie: interference, packet loss, corruption)

Single sideband modulation may be viewed as the removal or reduction of the amplitude modulation signal component. In order to see how the SSB is created, it is necessary to use an amplitude modulated signal as a starting point. (Rosu, NA)

function bpsk(x,fc,fs,br) %x is received signal input file usually *.mat file %fc is carrier frequency in Hz %fs is sampling frequency in Hz %br is bitrate in Hz %the command should be like this: %load input file onebit=fs/br; %number of samples per bit n=(length(x)-1)/onebit; %number of bits transmitted b=onebit; c=1; k=[]; for m=1:n; %iteration from 1 to number of bits y = x(c:b); % take the needed signal for one bit q=cos(2*pi*((c:b)-1)*fc/fs); %reference signal for Quadrature i=-cos(2*pi*((c: b)-1)*fc/fs); %reference signal for Inphase a=y.*q; % (received signal) . (reference signal for Quadrature)

Handheld radios will be used as the primary communication device. Each radio will be fully charged prior to the event, and set to channel 1.

Random Bernoulli generator generates binary data on a per frame basis. In data output, 144 samples per frame are used, and data rate is 36 Mbps.

It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects.

4. Radio: most common form of wireless transmission, typical of home routers and most wireless devices to use this form. Infared uses low frequency light waves to carry data using line-of-sight.

The COM-3011 operates by first mixing the received signal with 125 MHz, thus the data is now contained on it. The centre frequency is chosen by mixing a user specified radio synthesiser frequency with the 125 MHz together. For example to obtain a centre frequency of 100 MHz, the user would specify 225 MHz or -25 MHz. The bandpass filter will reduce the bandwidth to 40 MHz or 20 MHz either side of centre frequency [12]. This sample is the duplicated and the second part delayed by 90 degrees to form an in-phase and quadrature features.

QPSK or QAM. Also suppose that the kth carrier frequency for Xk is fk. Then, the

ANS: The entire process is performed by multiplying a radio frequency carrier and a pseudo-noise (PN) digital signal. The PN code is modulated onto an information signal using several modulation techniques such as quadrature phase-shift keying (QPSK), binary phase-shift keying (BPSK), etc. A doubly-balanced mixer then multiplies the PN modulated

As an Apple or Verizon executive, what legislation would you propose to the house and Senate committees to advance the reallocation of spectrum to wireless broadband? (Deal with the concerns raised by opponents of the reallocation and build broad support for reallocation)

"It's called frequency hopping," I said, "and it can help you guide a torpedo, which uses a transmitter and a receiver to make the frequencies jump at the same time by a radio signal."

3. Reverse-direction protocol – allows the ability to transfer control of an air channel between stations. This is especially good if the receiver is moving and the transmitters are trying to keep the best connection possible.

Frequency-hopping spread-spectrum (FHSS) is a method that uses a narrow band carrier that changes frequencies in a distinct pattern. The signal hops to a variety of frequencies, with the exact sequence of changes, known as the hopping sequence. At any moment, the broadcast signal uses only one frequency, or even several frequencies is not enough to effectively affect the communication between devices. The FHSS is used between 2.4 GHz and 2.5 GHz and operates at a data rate of about 1.6 Mbs per channel. Direct sequence spread-spectrum (DSSS) generates a bit pattern for each bit to be transmitted. This bit pattern is called a chip or chipping code (Kurose, 2003).

The field of communications is one in which the technologies are changing on an almost daily basis. Numerous different technologies have been pursued over the past few years; each designed to essentially accomplish several basic purposes in terms of community service. Three of the most actively pursued application include interactive distance learning, video conferencing, and entertainment. While it is the first two, video conferencing and interactive distance learning, which would serve to the best advantage in terms of education and business; it is the last, entertainment which has the most appeal to the largest number of people. The application of various communications applications in