A novel bit-interleaved coded modulation with iterative detection and decoding (BICM-IDD) receiver for multiple-input and multipleoutput (MIMO) systems using Max-Log-MAP algorithm is proposed. This receiver improves the detection and decoding performance by an improved turbo principle, in which pre-scaling the input information of the detector is performed at each iteration. From an information...

We now consider the problem of determining the number of points on an elliptic curve E over a finite field Fq. The most näıve approach one could take would be to evaluate the curve equation y2 = x3 + Ax + B for E at every pair (x, y) ∈ Fq , count the number of solutions, and add 1 for the point at infinity. This takes O(q2M(log q)) time. Note that the input to this problem is the pair of coeffi...

Level-Compressed (in short LC) tries were introduced by Andersson and Nilsson in 1993. They are compacted versions of tries in which, from the top down, maximal height complete subtrees are level compressed. We show that when the input consists of n independent strings with independent Bernoulli (p) bits, p 6= 1/2, then the expected depth of a typical node is in probability asymptotic to log lo...

We give algorithms for approximation by low-rank positive semidefinite (PSD) matrices. For symmetric input matrix A ∈ Rn×n, target rank k, and error parameter ε > 0, one algorithm finds with constant probability a PSD matrix Ỹ of rank k such that ‖A− Ỹ ‖2F ≤ (1+ε)‖A−Ak,+‖ 2 F , where Ak,+ denotes the best rank-k PSD approximation to A, and the norm is Frobenius. The algorithm takes time O(nnz(A...

In this paper we examine the average running times of Batcher's bitonic merge and Batcher's odd-even merge when they are used as parallel merging algorithms. It has been shown previously that the running time of odd-even merge can be upper bounded by a function of the maximal rank diierence for elements in the two input sequences. Here we give an almost matching lower bound for odd-even merge a...

Level crossing rate, outage probability and average time of fade duration of the SSC combiner output signal are determined in this paper. Log-normal fading at the input is present. The results are shown graphically for different variance values, decision threshold values and fading parameters values. Key-Words: Diversity reception, Fade Duration, Level Crossing Rate, Log-normal fading, Outage P...

A space-efficient approximation algorithm for the grammar-based compression problem, which requests for a given string to find a smallest context-free grammar deriving the string, is presented. For the input length n and an optimum CFG size g, the algorithm consumes only O(g log g) space and O(n log∗n) time to achieve O((log∗n) logn) approximation ratio to the optimum compression, where log∗n i...

We present a deterministic algorithm running in space O ? log 2 n= log logn solving the connectivity problem on strongly unambiguous graphs. In addition, we present an O(logn) time-bounded algorithm for this problem running on a parallel pointer machine.

The paper is devoted to the quantum implementation of the decoding of the (classical) simplex code of length n. The implementation attempts at trading off time complexity with circuit complexity of decoding. We suggest a quantum decoding algorithm that operates on a circuit of size O(log n) and has time complexity O(log n). It also requires an additional circuit of size O(n) needed to gain bitw...