A Serial Unequal Error Protection Code System Using Multilevel Trellis Coded Modulation with Ring‐type Signal Constellations for AWGN Channels

Abstract

We propose a serial unequal error protection (UEP) code system for use with information sources that contain a mixture of both important and less important data. To achieve UEP, the proposed scheme uses a form of Trellis coded modulation (TCM) which encodes the data by switching between some codes that use different signal constellations. So we propose ring-type signal constellations with M levels of importance (MRING). Also, as no extra information about which code is used is added, the receiver estimates which code was used in the transmitter by examining the received signal points. In this paper, theoretical analyses of the 2RING signal constellations (that is, for M = 2) and TCM codes are presented, and the effectiveness and the validity of the system for additive white Gaussian noise (AWGN) channels are confirmed using theoretical analyses and computer simulations. 

A Serial Unequal Error Protection Codes System Using MMSE-FDE for Fading Channels

“…In [8], we describe the difference between the proposed system and previous systems in detail. In this section, we describe methods using a non-uniform signal constellation, methods using coded modulation with time multiplexing as typical previously proposed UEP schemes [4], [5].…”

“…In previous research, we proposed an improvement of the time multiplexing approach mentioned in [4], [5]. Moreover, the effectiveness of the proposed UEP system for additive white Gaussian noise (AWGN) channels was shown using theoretical analysis and computer simulations [8].…”

“…However, these systems are for slow fading and there have been few UEP systems using techniques to combat fast and selective fading aggressively. In this paper, we propose a UEP system using MMSE-FDE (frequencydomain equalization based on the minimum mean square error criterion) [12], [13] for fast and selective fading by using the fact that importance levels are changed every few symbols, i.e., every block, in the proposed system [8]. As a result, lower computational cost and better BER performance are expected for broad-band transmissions.…”

The A3D-TC: An Adaptive Approach for Selecting Third Component Parameters to Generate Robust Turbo Codes

“…Initially the digital information is transformed into analog waveform by the modulator and is transmitted over a noisy medium, and is again converted back into a sequence of symbols at the receiver by the demodulator [16]. In certain communication systems, information requires different levels of protection against noise since the sequence of the information may consist of a number of parts that have different degrees of significance [8]. Thus in the information received over communication channels, it is very vital for communication systems to have sufficient means for the discovery and correction of errors [17].…”

“…The set of symbols to which meanings or values are attached are known as codes [3]. They are designed to offer different levels of data protection [8]. A sequence of transmitted bits is transformed to a longer sequence of bits (codeword) by adding extra bits in error correction codes.…”