Hengzhou Xu

Zhoukou Normal University · school of network engineering

Considering limited pilot and storage resources in satellite communications, we propose an efficient correlation-based reception scheme consisting of a “parallel” frequency-phase estimation (PFPE) mode and a data blockwise compensation (DBC) scheme. In specific, the PFPE mode provides an autocorrelation (AC) frequency offset estimator and a maximum...

In this paper, we discuss general data-framing and optimization, parallel frequency-phase estimation, and powerful frequency estimator for satellite communications. Based on the standard pilot-symbol-assisted-modulation (S-PSAM) frame, we design a general PSAM (G-PSAM) frame, whose corresponding data-aided & non-data-aided Cramér-Rao bound (DA&NDA...

In this paper, we study a class of nonbinary LDPC (NBLDPC) codes whose parity-check matrices have column weight 2, called NBLDPC cycle codes. We propose a design framework of 2,ρ-regular binary quasi-cyclic (QC) LDPC codes and then construct NBLDPC cycle codes of large girth based on circulants and finite fields by randomly choosing the nonzero fie...

In this paper, we study the cycle structure of (3, 19)-regular Tanner’s quasi-cyclic (QC) LDPC codes with code length 19p, where p is a prime and p ≡ 1 (mod 57), and transform the conditions for the existence of cycles of lengths not more than 10 into polynomial equations in a 57th root of unity of the prime field Fp. By employing the Euclidean div...

In this paper, we investigate the problem of energy-efficient routing design from a sensor node to a sink node under a given delay constraint. The network topologies in duty-cycle wireless sensor networks (WSNs) are changed from one time-slot to another due to each sensor node’s active/dormant schedule. A series of network topologies over a period...

As a general framework, partial geometries play an important role in constructing good low-density parity-check (LDPC) codes with low error-floors. Partial geometries from row–column constrained (RC-constrained) arrays of circulant permutation matrices (CPMs) have been determined by Q. Diao et al. In this paper, we study partial geometries from RC-...

In this paper, we investigate the energy-efficiency for amplify-and-forward relay networks in the presence of channel estimation errors. Two kinds of transmission strategies, i.e., direct transmission (DT) and relay transmission (RT), are dealt with for the energy-efficient communication system design. The energy cost function in DT or RT is define...

In this paper, the girth distribution of Tanner’s (3,17)-regular quasi-cyclic LDPC (QC-LDPC) codes with code length 17p is determined, where p is a prime and p≡1(mod51). By analyzing their cycle structure, five equivalent types of cycles with length not more than 10 are obtained. The existence of these five types of cycles is transmitted into polyn...

This paper addresses an engineering problem that measurement errors in intensity and mapping dimensions exist in the track-before-detect (TBD) architecture simultaneously. Drawing lessons from the probability data association (PDA) and the basic generalized likelihood ratio test TBD (GLRT-TBD), the joint log-likelihood ratio test TBD (JLLRT-TBD) me...

In this paper, we study a special class of quasi-cyclic LDPC (QC-LDPC) codes, the array codes proposed by J. Fan. We first generalize the array codes from primes to arbitrary positive integers, and then construct QC-LDPC codes by employing the row and column selection method. For given numbers of rows and columns, we can obtain the non-isomorphic r...

Routing design is an effective mechanism to improve the energy‐efficiency in packet transmissions for wireless multihop networks. Meanwhile, the total energy consumption for packet transmissions over a path comprising of several unreliable links depends on the power assignment on each link. In this study, the authors address the energy‐efficient ro...

We consider a low-density parity-check (LDPC) coded non-recursive Gaussian minimum shift keying (GMSK) scheme for space communications subject to low signal-to-noise ratio (SNR), limited power and spectrum resources. First, we design a non-recursive continuous-phase encoder (NRCPE) based GMSK modulator to alleviate the impact of the error propagati...

In space communications, there exist two prominent issues: large Doppler spread and limited pilot resources, which will result in poor performance for a pilot-aided (PA) traditional carrier synchronization mode (TCSM) with serial processing. In view of this, we propose a frequency-phase decoupling method (FPDM) based on an unbiased auto-correlation...

In this paper, three kinds of transmission strategies are dealt with: 1) direct transmission without relay; 2) relay transmission without a direct link; and 3) relay transmission with a direct link. We first develop an analytical framework for the total energy consumption per transferred payload bit in amplify-and-forward wireless relay networks. I...

Girth is an important structural property of low-density parity-check (LDPC) codes. Motivated by the works on the girth of Tanner (3, 5), (3, 7), (3, 11), and (5, 7) quasi-cyclic (QC) LDPC codes, we in this paper study on the girth of Tanner (3, 13) QC-LDPC codes of length 13p for p being a prime of the form (39m + 1). First, the cycle structure of...

Girth plays an important role in the design of low-density parity-check (LDPC) codes. Motivated by the works on the girth of some classes of Tanner quasi-cyclic (QC) LDPC codes, e.g., Tanner (3,5), (3,7), (3,11), and (5,7) codes, we in this paper study the girth of Tanner (J,L) QC-LDPC codes where J and L can be any two positive integers. According...

Quasi-cyclic LDPC (QC-LDPC) codes have been accepted as the standard codes of 5G enhanced mobile broadband data channel. These standard codes are designed to support multiple lifting sizes and possess rate-compatible property, which can help adapt various information lengths and code rates well. In this paper, we propose an algebra-assisted method...

As a class of capacity-approaching codes, nonbinary low-density parity-check (LDPC) codes have attracted much attention because of noticeable performance. Nonbinary LDPC-coded modulation systems which have excellent performance for high spectral efficiency transmission are also potential schemes in the future communication system. In this paper, we...

This paper presents a family of rate-compatible (RC) globally coupled low-density parity-check (GC-LDPC) codes, which is constructed by combining algebraic construction method and graph extension. Specifically, the highest rate code is constructed using the algebraic method and the codes of lower rates are formed by successively extending the graph...

Quasi-cyclic (QC) LDPC codes play an important role in 5G communications and have been chosen as the standard codes for 5G enhanced mobile broadband (eMBB) data channel. In this paper, we study the construction of QC LDPC codes based on an arbitrary given expansion factor (or lifting degree). First, we analyze the cycle structure of QC LDPC codes a...

In this paper, we investigate the topology design to balance the network cost and connectivity, which are two important metrics to guide the design of network topology in ad hoc networks. To this end, we focus on how to construct the network topology, which has the minimum network cost subject to a connectivity constraint. A new topology metric for...

Quasi-cyclic (QC) LDPC codes whose parity-check matrices have diagonal structure play an important role in channel coding of 5G communications. In this paper, we study an algebraic-based method for constructing QC LDPC codes with diagonal structure of parity-check matrices. We first analyze the cycle structure of this class of QC LDPC codes and the...

The down link communication environment of high-speed railway (HSR) is modeled by multi-user Gaussian Z interference channel (GZIC) model in the paper. The sum-capacity and the optimum transmission solution of multi-user GZIC are obtained in the strong interference regime. Based on the optimum solutions in all interference regimes, the multi-dimens...

This paper presents a nonbinary low-density parity-check coded spatial modulation for multiple-input multiple-output (MIMO) communication systems, in which the information bits for choosing active transmit antennas and the bits for choosing constellation signals are protected by a nonbinary LDPC code. We apply a many-to-one mapping known as Gallage...

The girth plays an important role in the design of LDPC codes. In order to determine the girth of Tanner (5, 7) quasi-cyclic (QC) LDPC codes with length 7p for p being a prime with the form 35m+1, the cycles of lengths 4, 6, 8, and 10 are analyzed. Then these cycles are classified into sixteen categories, each of which can be expressed as an ordere...

Motivated by the works on the girth of Tanner and quasi-cyclic (QC) low-density parity-check (LDPC) codes done by S. Kim et al. and M. Gholami et al., respectively, we analyze the cycles of Tanner QC LDPC codes and present the sufficient and necessary conditions for the existence of cycles of lengths 4, 6, 8, and 10 in Tanner QC LDPC codes. By chec...

In this paper, we focus on short-block nonbinary LDPC (NB-LDPC) codes based on cyclic codes. Based on Tanner graphs' isomorphism, we present an efficient search algorithm for finding non-isomorphic binary cyclic LDPC codes. Notice that the parity-check matrix H of the resulting code is square and not of full rank, and its row weight and column weig...

We propose a multiple-voting based joint detectiondecoding algorithm for nonbinary LDPC-coded modulation systems. This algorithm is inspired from the reliability-based joint detection-decoding (JDD) algorithm for nonbinary LDPC-coded modulation systems that has been proposed recently, in which the accumulated reliability of symbols based on one-ste...

In this paper, we study the rank of matrices over and propose two construction methods for algebraic-based nonbinary LDPC codes from an existing LDPC code, referred to as the original code. By multiplying all elements of each column of the binary parity-check matrix H corresponding to the original code with the same nonzero element of any field, th...

In this letter, we study the construction of quasicyclic (QC) LDPC codes by array dispersion and masking. We first propose a class of arrays of circulant permutation matrices (CPMs) of arbitrary size obtained by dispersion. Based on this class of arrays of CPMs, a class of QC-LDPC codes is constructed. For these resulting codes, we analyze their cy...

There exist lots of (3, L)-regular quasi-cyclic (QC) LDPC codes constructed from finite fields, protographs, array codes, and computer search under some design rules. For a given code length and rate, how to select the best one from these codes is considerable. In this paper, we study (3, L)-regular QC LDPC codes from the perspective of graph isomo...

In this letter, we consider the construction of q-ary low-density parity-check (LDPC) codes by jointly optimizing the girth and number of shortest cycles in the frame of superposition. We begin with constructing binary quasi-cyclic LDPC codes by superposition. By replacing the nonzero entries of the parity-check matrices of the resulting binary cod...