Frequency hopping is type of spread spectrum encoding method which has a advantages of spreading data over wide bandwidth, makin jamming and interception harder and immunity from various noises and distortions.
Under Spread spectrum concept, input is provided to channel encoder which produces narrow bandwidth analog signal around central frequency. Signal is modulated using sequence of digits by typically spreading code and it is generated by pseudonoise or pseudorandom nuber generator. Receiver uses same sequence to demodulate signal. A typical block diagram is shown below
Frequency hopping is sigal broadcast over seemingly random series of frequencies. Receiver as well hops between frequencies to be in synchronization with transmitter. Advantages are eavesdropping becomes very difficult and jamming one frequency will make very less impact.
Basic operation is typically 2k carriers frequencies forming 2k channels, in which channel crossing corresponds with bandwidth of input, Each channel is used for fixed interval i.e. 300 ms in IEEE 802.11, some number of bits transmitted using some encoding scheme (May be fractions of bit). Sequence is dictated by spreading code.
Below are the pictures of Frequency hopping example, transmitter and receiver.
Transmitter:
Receiver:
The nature of FHSS depends on Tc (Frequency shifter every Tc seconds) and Ts (Duration of signal element). slow FHSS has Tc>Ts and vice versa.
Report about Frequency hopping in wireless communication systems With refrences: citation
Which of the following wireless standards uses frequency-hopping spread spectrum (FHSS) by default? A. Bluetooth B. 802.11a C. 802.11b D. 802.11g
Sound Systems Inc.produces and markets wireless speakers. Management is thinking about developing a new model, the SonicBoom. TheSonicBoom will cost approximately $59 per unit to produce, and will be sold to retailers (such as Fry’sand Best Buy) at a price of $119, with a suggested retail price (i.e., the amount charged by retailers to consumers) of $239. Sound Systems Inc.estimates that it will incur annual costs of $7.5 million to advertise and promote the SonicBoom, $2.5 million to cover selling and...
Write short report about cache memory organizations .The report should be between (3-6) pages .The report should include: o Introduction about basics of caches o Measuring and improving cache perfomance O IMeasuring and improving cache perfomance o Referencing and citation
1-A) Sound Systems Inc.produces and
markets wireless speakers. Management is thinking about developing
a new model, the SonicBoom. TheSonicBoomwill cost
approximately $59 per unit to produce, and will be sold to
retailers (such as Fry’sand Best Buy) at a price
of $119, with a suggested retail price (i.e., the amount charged by
retailers to consumers) of $239. Sound Systems
Inc.estimates that it will incur annual costs of $7.5 million
to advertise and promote the SonicBoom, $2.5 million to
cover selling and...
The questions are about Fundamentals of Communication Systems,
and Random variables and probability.
Please answer for the below one problem.
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Problem 3 Find the output autocorrelation function for a delay line with delay A when...
A wireless communication company is considering switching from a per-minute charge to a flat monthly fee for unlimited service. It anticipates that this will result in greater usage and would like to estimate what the average number of minutes per month per customer will be under the new plan. To do this, it offers 1000 customers the flat-fee plan for one month and tracks their usage. From past data, the company knows that the standard deviation of monthly minutes is...
Communication systems
d) The angle modulated signal is presented as = 1008 (2*10*4 +0.5sin(10*x+)) 1. Find and determine the frequency modulated signal x(C) with k, = 5. (5 marks) II. Calculate and find out the message signal m(t). (5 marks) e) A 40 MHz carrier is frequency-modulated by a sinusoidal signal with mascimum frequency deviation of 500 KHz. I. Find and calculate the approximate bandwidth of the FM signal the frequency of the message signal is 1 kHz. (5 marks)...
New Age Electronics Ltd is a business that is engaged in research focusing on wireless communication technologies. The company recently developed a new set of wireless head phones that work on the frequency modulation (FM) signal and is currently considering whether or not to go for mass production. The Board of Directors will soon meet to make a final decision and has the following information available to help it decide: • The cost of developing the headphones has been N$1...
According to your textbook, which of the following statements about cell signaling for communication between cells is true? Select one: a. Archaea and eukaryotes have cell signaling systems, but not bacteria. b. Signalling systems only exist in multi-celled eukaryotes. c. Signalling systems are found in all eukaryotes, both multi-celled and single celled, but not in bacteria or archaea as they lack sexual reproduction and multi-cellularity. d. Signalling systems have been identified in single celled and multi-celled eukaryotes and bacteria Clear...
A communication plan is used for the following reason: 1. To educate the stakeholders about the progress and outcomes of the project. 2. To inform stakeholders about the impacts of the project in their day to day lives. 3. To report metrics to management regarding project scope, budget, schedule, and quality. 4. To train the end users of the project 5. To inform stakeholders how to be aware of project communications. 6. To inform end users of the project details.