On the Hamming Weight Distribution of Subsequences of Pseudorandom Sequences
This work addresses the design of pseudorandom sequences for coding applications, offering incremental improvements in understanding subsequence properties.
The paper characterizes the average Hamming weight distribution of subsequences of m-sequences, deriving a lower bound on the minimum Hamming weight and demonstrating via simulations that properly chosen subsequences can form a rateless code meeting the normal approximation benchmark.
In this paper, we characterize the average Hamming weight distribution of subsequences of maximum-length sequences ($m$-sequences). In particular, we consider all possible $m$-sequences of dimension $k$ and find the average number of subsequences of length $n$ that have a Hamming weight $t$. To do so, we first characterize the Hamming weight distribution of the average dual code and use the MacWilliams identity to find the average Hamming weight distribution of subsequences of $m$-sequences. We further find a lower bound on the minimum Hamming weight of the subsequences and show that there always exists a primitive polynomial to generate an $m$-sequence to meet this bound. We show via simulations that when a proper primitive polynomial is chosen, subsequences of the $m$-sequence can form a good rateless code that can meet the normal approximation benchmark.