MIMO radars (Multiple‑Input Multiple‑Output) act like a robot's eyes: more antennas, more detail. To make them even more efficient, scientists designed a hybrid algorithm called IFWA‑SA, blending two optimization techniques: the Fireworks Algorithm (FA) and Simulated Annealing (SA). FA works like a firework: it starts from a central point and "explodes" in many directions, quickly exploring the solution space. SA, on the other hand, is more patient: it occasionally accepts worse solutions to jump out of local traps, like a traveler taking a detour to find a better shortcut. To prevent initial points from clustering, the researchers use Sobol sequences, a near‑perfect grid that spreads the first candidates uniformly. The outcome is a sparse antenna layout that reduces side‑lobes, the unwanted waves that can confuse the radar. In tests, IFWA‑SA lowered side‑lobe levels by 1.3‑3.8 dB compared to traditional methods like PSO, GA, or GWO, showing faster convergence and higher precision. In practice, this algorithm makes radars sharper, more reliable, and better equipped for complex environments, paving the way for smarter autonomous vehicles, drones, and surveillance systems.
The Fireworks Algorithm (FA) is a meta‑heuristic inspired by the dynamics of an explosion: a starting point (center) generates a number of "sparks" that disperse throughout the solution space. Each spark represents a possible antenna array configuration, evaluated via a fitness function that combines side‑lobe level (PSL) and element density. The discrete variant of FA used in this study enforces that antenna positions are integer values, respecting minimum spacing constraints to avoid physical interference. Simultaneously, Simulated Annealing (SA) introduces a "temperature" mechanism that controls the probability of accepting worse solutions: early on, with high temperature, the algorithm explores widely; as temperature decreases, the search focuses on promising regions, reducing the risk of getting trapped in local minima. The IFWA‑SA integration leverages FA for fast global exploration, while SA fine‑tunes the most promising solutions locally. Sobol sequences, unlike random generation, provide quasi‑uniform points in the multidimensional space, ensuring more complete coverage of the search domain from the first step. In benchmarks, IFWA‑SA was compared with PSO, GA, GWO, and pure SA. Results show an average PSL reduction of 1.3‑3.8 dB, with faster convergence (fewer iterations) and greater robustness to variations in initial parameters. This approach is especially beneficial for sparse array synthesis, where side‑lobe minimization is crucial for improving angular resolution and reducing interference in high‑target‑density monitoring scenarios. Moreover, the framework's flexibility allows extending optimization to additional criteria, such as reducing power consumption or enhancing fault tolerance, making IFWA‑SA a promising platform for future generations of MIMO radars.
