Implementing and designing a secure information system based on the DSSS gold sequence using MATLAB

Abstract

During study of directly spread spectrum systems, noted that this system uses many types of code to spread data through communication process. There are different types of code sequences available with good correlation properties, they often use pesudo sequence for spreading which is to be less efficient in protecting information from the breaches that attack the communications systems from penetration. In this article gold sequence will use, which is consider better and more complex than the rest of the code sequence (pseudo-noise (PN) sequence, barker code, hadamard code, and others) in terms of the security aspect of the information, thereby it is difficult to detect the information sent in addition to that it is used in code-division multiple access. Design and implement difficult code to protect information in the communication system carried out here by using MATLAB, for sending a binary data and color photo to be sure that this system is working properly with few errors and better information protection than the rest of the other code that is used in direct sequence spread spectrum.

Reconfigurable linear feedback shift register for wireless communication and coding

“…The test inputs and outputs help to understand the functionality of design. Test input for LFSR-1: sequence input, Shift_data_in_LFSR1 (4:0)="10000", Tap inputs [5,2] as Tap Sequence_LFSR1 (4:0)="01001", the output of LFSR-1(30:0)=000 0100 1011 0011 1110 0011 0111 0101 (in binary)=04B3E375 (hexadecimal). Test input for LFSR-2: sequence input, Shift_data_in_LFSR2 (4:0)="10000", Tap inputs [5 4 2 1] as Tap_Sequence_LFSR2 (4:0)="11011", the output of LFSR-1(30:0)="000 0111 0011 0111 1101 0001 0010 1011" (in binary)=04B3E375 (hexadecimal).…”

“…The chip functionality follows the steps of the chip design, and simulation modeling. The Verilog hardware description language (VHDL) programming is used to design the LFSR-1 chip that accepts the 5-bit input stream with the tap sequence (5,2). After that, the LFSR-2 chip is designed that also accepts the 5-bit input stream with the tap sequence (5, 4, 2, 1).…”

“…Optical LFSRs, which have the advantage of speed, are predicted to provide benefits in similar types of applications. Optical fiber shift registers [5] with the integration of XOR gate [6], [7] and semiconductor optical amplifier (SOA), having low transferring energies and advanced switching speeds (>40 Gb/s) proved to achieve this goal. The enormous length of optical shift registers limits the usefulness of optical LFSRs because of the complexity of programming while generating the regulated PRBSs.…”

Turbo encoder and decoder chip design and FPGA device analysis for communication system

“…The MAP algorithm [26] comprises addition processes and multiplication processes. For a large classification, the logarithm and estimate are applied, and the (3) for Max log-MAP is specified as (4).…”

“…The noise corrupts the data [3] due to which failure in data transmission occurs. Therefore, error detection and error correction [4] play an important role in data communication. For this purpose, different channel coding techniques are used.…”