Radar ambiguity functions and resolution characteristics of Sudoku-based waveforms

Sudoku Inspired Designs for Radar Waveforms and Antenna Arrays

“…Another example of a Costas code solution was found when looking at 9 × 9 Sudoku matrices. The sequence [9,1,4,5,3,7,6,8,2] corresponds to the locations of the ones in the following Sudoku matrix shown in Figure 11. This sequence is a Costas code, but cannot be translated or rotated to fill in the remaining spaces.…”

“…Previously, we investigated the use of Sudoku puzzles as a means to realize frequency-coded waveforms [6] similar to the well-known Costas coded sequences [7]. We explored the auto-ambiguity and cross-ambiguity functions of different Sudoku-coded waveforms and compared them to traditional Costas sequences and random sequences.…”

Sudoku sequences, Costas sequences, and random permutations in a multi-sub-FDA radar

“…Furthermore, the array architecture follows a multi-sub-FDA transmission and receiving setup based on the work of Xu et al 5 The introduction of Sudoku based frequency offset schemes follows a new avenue research started by Narayanan et al wherein the authors analyze the potential Sudoku and Latin squares have for prescribing frequency-hopped radar waveforms. 6 The work on Sudoku was furthered by Bufler et al, who studied array element nulling schemes and beamsteering based on Latin Squares for use in antennas and radar applications. 7 Additionally, the formal Doppler tolerance of Sudoku and Costas based frequency hopped waveforms was studied by Correll et al 8 The motivation for these works stemmed largely from the work of Newton and Desalvo, who found that both Sudoku and Latin Square matrices have a higher Shannon entropy than randomly generated matrices of the same order.…”