Design of serial concatenated msk schemes based on density evolution

Abstract

We consider the design of convolutional codes and low-density parity-check (LDPC) codes with minimum-shift keying (MSK) when the receiver employs iterative decoding and demodulation. The main idea proposed is the design of coded schemes that are well matched to the iterative decoding algorithm being used rather than to hypothetical maximum-likelihood decoding. We first show that the design is crucially dependent on whether the continuous phase encoder (CPE) is realized in recursive form or in nonrecursive form. We then consider the design of convolutionally coded systems and low density parity check codes with MSK to obtain near-capacity performance. With convolutional codes, we show that it is possible to significantly improve the performance by using a mixture of recursive and nonrecursive realizations for the CPE. For low density parity check codes, we show that codes designed for binary phase shift keying are optimal for MSK only if the nonrecursive realization is used; for the recursive realization, we design new LDPC codes based on the concept of density evolution. We show that these codes outperform the best known codes for MSK and have lower decoding complexity.

Trellis Coded Multi-h CPM for Serially Concatenated Schemes

“…Multiple indices sometime could benefit both on convergence threshold and error floors. Krishna R. Narayanan designed serially concatenated convolutional coded and Low-Density Parity-Check (LDPC) coded MSK schemes [4], and based on density evolution, make the design matched to the iterative decoding algorithm, and get valuable results. However, such schemes just paid attention to MSK signal, and other CPM signals were not concerned.…”

Coherent continuous-phase frequency-shift keying: Parameter optimization and code design

“…Iterative demodulation and decoding of CPM with binary convolutional codes is considered in [8], [9] and with nonbinary convolutional codes in [10]. Narayanan et al [11] consider a low-density parity-check (LDPC) coded minimum-shift keying (MSK) system. Ganesan [6] considers matched bitinterleaved coded-modulation (BICM) systems consisting of an outer LDPC code that is matched to the CPM modulation.…”

Serially concatenated continuous phase modulation with symbol interleavers: performance, properties and design principles

“…In addition to SCCPM, more concatenated and iterative detection schemes for CPM have been proposed and also shown excellent performance, such as low-density paritycheck (LDPC) codes for MSK [5], woven coded CPM [6,8,9]. However, it is still valuable to investigate the performance improvement approach for SCCPM due to its structural and implementing simplicity.…”