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Summary: In this paper, we propose an efficient method for generating two types of novel optimized long binary spreading sequences (OLBSS) with improved autocorrelation function (ACF) properties. The first type is constructed from concatenated short binary subsequences belonging to the same code family, such as Walsh Hadamard and Gold subsequences, provided that their cross‐correlation functions (CCFs) have good properties. The second category uses the same subsequences but which are rather interlaced. Here, the number and size of the subsequences are related to the chosen length of the final constructed long sequence and the desired performances. The realization of the OLBSSs is achieved using two different optimization techniques, namely, the genetic algorithms (GAs) and particle swarm optimization (PSO) method. The simulation results, based on MATLAB tool, have shown that the proposed long sequences, composed of Walsh–Hadamard subsequences and optimized by the GA, have better ACF properties compared to the original Gold, Weil, and random sequences of the same length. [ABSTRACT FROM AUTHOR]

We propose a simpler and faster Gold codes generator, which can be efficiently initialized to any desired code, with a minimum delay. Its principle consists of generating only one sequence (code number 1) from which we can produce all the other different signal codes. This is realized by simply shifting this sequence by different delays that are judiciously determined by using the bicorrelation function characteristics. This is in contrast to the classical Linear Feedback Shift Register (LFSR) based Gold codes generator that requires, in addition to the shift process, a significant number of logic XOR gates and a phase selector to change the code. The presence of all these logic XOR gates in classical LFSR based Gold codes generator provokes the consumption of an additional time in the generation and acquisition processes. In addition to its simplicity and its rapidity, the proposed architecture, due to the total absence of XOR gates, has fewer resources than the conventional Gold generator and can thus be produced at lower cost. The Digital Signal Processing (DSP) implementations have shown that the proposed architecture presents a solution for acquiring Global Positioning System (GPS) satellites signals optimally and in a parallel way. [ABSTRACT FROM AUTHOR]

Graph: Figure 1 LSFRs based C/A Gold codes generator. The HT ht register has the polynomial HT ht REFERENCES 1 Rouabah K., Attia S., Harba R., Ravier P., Boukerma S. Optimized method for generating and acquiring GPS Gold codes. In the article titled "Optimized Method for Generating and Acquiring GPS Gold Codes" [[1]], the authors identified an error in Figure 1, where the I x i SP 6 sp connection was missing. [Extracted from the article]