Convert The Binary Data “011010” Into Analog Waveforms ✓ Solved

Convert the binary data “011010†into analog waveforms

Convert the binary data "011010" into analog waveforms using the following modulation techniques: a. Two-level Amplitude Shift Keying, b. Two-level Frequency Shift Keying, c. Two-level Phase Shift Keying, d. Differential Phase Shift Keying, e. Four-level Amplitude Shift Keying, f. Four-level Phase Shift Keying, g. Eight-level Amplitude Shift Keying.

With fc = 500 kHz, fd = 25 kHz, and M = 16 (L = 4 bits), compute the frequency assignments for each of the sixteen possible 4-bit data combinations.

Draw the approximate Analog Modulation and Frequency Modulation waveforms in complete steps for the following signal.

Draw the 16 QAM Constellation Diagram having two different amplitude levels and eight different phase levels.

Explain and draw the Error Detection Process for Cyclic Redundancy Check (CRC).

Compute the frame check sequence for the given information: Message = , Pattern = . Compute the transmitted signal using Direct Sequence Spread Spectrum for the given information: Input: 1011, Locally Generated PN bit stream: , T = 3Tc.

What is the difference between Infrastructure and ad hoc modes in WLAN? Draw their relative diagrams as well.

Compare the differences of TCP and OSI protocols for wired and wireless LANs using diagrams.

Explain why the square and circle shapes cells for cellular communications are not appropriate as compared to hexagonal shape cells.

Paper For Above Instructions

The conversion of binary data into analog waveforms is a fundamental aspect of data transmission in telecommunications. Various modulation techniques can be employed to achieve this conversion, including Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Phase Shift Keying (PSK), and others. This paper details the methods required to convert the binary sequence "011010" into its corresponding analog waveforms.

Modulation Techniques for Binary Data

The binary sequence "011010" will be modulated using several techniques:

  • Amplitude Shift Keying (ASK): In ASK, the amplitude of the carrier signal is varied to represent binary data. For the sequence "011010", we would represent a '1' by a high amplitude and a '0' by a low amplitude, creating an analog signal that switches between these two levels.
  • Frequency Shift Keying (FSK): FSK conveys data using discrete frequency changes of a carrier wave. In the context of "011010", two frequencies: one for '1' and another for '0', will be defined. For instance, '1' could correspond to 500 kHz, while '0' could correspond to a lower frequency, presenting a varied frequency waveform.
  • Phase Shift Keying (PSK): In PSK, the phase of the carrier signal is shifted to encode binary data. For "011010", different phase shifts represent the bits, where, for example, a shift by 0 degrees could represent '1' and a shift by 180 degrees could represent '0'.
  • Differential Phase Shift Keying (DPSK): This technique encodes data based on the phase difference between successive symbols rather than the absolute phase. Each change from the previous state indicates a bit value.
  • Four-Level Amplitude Shift Keying (4-ASK): In this technique, four different amplitudes are used. This allows encoding of two bits per symbol which enhances data transmission efficiency.
  • Four-Level Phase Shift Keying (4-PSK): Similar to 4-ASK but utilizing phase shifts, allowing two bits per symbol based on four different phase shifts.
  • Eight-Level Amplitude Shift Keying (8-ASK): Here, eight different amplitudes are utilized, and can represent three bits with each symbol.

Frequency Assignments for 4-bit Combinations

Given fc = 500 kHz and fd = 25 kHz, the frequency assignments can be computed using the formula:

Frequency = fc + n * fd for n = 0, 1, ..., 15, where n corresponds to the decimal representation of each 4-bit combination.

The frequency for each combination can be tabulated:

  • 0000 -> 500 kHz
  • 0001 -> 525 kHz
  • 0010 -> 550 kHz
  • 0011 -> 575 kHz
  • 0100 -> 600 kHz
  • 0101 -> 625 kHz
  • 0110 -> 650 kHz
  • 0111 -> 675 kHz
  • 1000 -> 700 kHz
  • 1001 -> 725 kHz
  • 1010 -> 750 kHz
  • 1011 -> 775 kHz
  • 1100 -> 800 kHz
  • 1101 -> 825 kHz
  • 1110 -> 850 kHz
  • 1111 -> 875 kHz

Analog and Frequency Modulation Waveforms

Analog modulation involves varying a carrier signal in accordance with a message signal. Frequency modulation (FM) is characterized by the frequency deviation of the carrier wave being proportional to the amplitude of the input signal. To illustrate these modulations, waveforms must be plotted. Typically, the x-axis of these graphs represents time, while the y-axis indicates amplitude (for AM) or frequency (for FM).

QAM Constellation Diagrams

The 16-QAM constellation diagram represents a signal combining different amplitude levels and phase shifts. This diagram visualizes how each symbol corresponds to a different point in the constellation, facilitating efficient signal transmission.

Error Detection Process for CRC

Error detection is crucial in communications. CRC involves appending a sequence of bits to a message to detect errors during transmission. This method encapsulates the original message into a polynomial form which can be checked at the receiver end for errors.

Frame Check Sequence (FCS)

To compute the FCS for a given message and pattern, one would typically employ polynomial long division, ensuring any remainder generated during division is appended to the message to create the frame check sequence.

Ad Hoc vs Infrastructure Modes in WLAN

Ad hoc networks allow direct communication between devices without a central access point, relying on peer-to-peer connectivity. In contrast, infrastructure mode necessitates an access point which manages communication, increasing security and efficiency.

Comparison of TCP and OSI Protocols

The TCP/IP model and the OSI model represent two foundational frameworks for computer networking. TCP/IP is practical and specifically designed for communication across the Internet, while OSI serves as a theoretical framework guiding various technologies. The OSI model includes seven layers, while TCP/IP condenses this into four layers, making it simpler yet robust for modern networking environments.

Hexagonal Cellular Architecture

Hexagonal cell design is preferred over circular or square layouts in cellular communication due to its efficient coverage of an area and eliminating overlap. This geometry allows frequency reuse by enabling co-located cells to minimize interference.

Conclusion

The effective transmission of data hinges on the proper implementation of modulation techniques, error detection, and understanding of network architecture. Each method discussed plays a pivotal role in ensuring robust communication systems capable of managing both wired and wireless data environments.

References

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