Labeling-Based Recipient Identification for 16-QAM BICM-ID

Abstract

In recent years, many efforts have been made to find the optimal labeling maps for bit-interleaved coded modulation with iterative decoding (BICM-ID) with the aim to exploit the benefits of iterative decoding to the maximal extent. The current paper reveals new opportunities that BICM-ID signal labeling brings for system designers: it enables recipient addressing without any explicitly sent identifier. Instead, the recipient ID is represented by a labeling map, selected from a set of equally optimal labelings. A simple method of frame filtering, necessary to retrieve the desired data frame at the receiver side, is proposed and evaluated. It is also shown that the proposed Labeling-Based Recipient Identification (LABRID) approach does not cause any inferior performance outcome in terms of bit error rate.

BICM-ID Labeling-Based Recipient Identification in a Heterogeneous Network

“…The resultant interleaved codeword ( ) is sliced into M -bit long blocks, i.e., ; each block is mapped onto a single constellation point by the symbol mapper. The labeling map, used for symbol mapping, depends on the recipient identifier, i , which is obtained from the MAC layer, according to the LABRID principles [ 10 ]. (For 16-QAM modulation, there are 768 asymptotically optimal labeling maps: , which bring equally good BER vs. performance after iterative decoding.)…”

“…The key idea presented in the figure is to model a mechanism that blocks foreign frames from passing to the MAC layer. Similar to the first work on LABRID [ 10 ], this procedure is based on observing the convergence of the iterative process. Specifically, the mean of the absolute extrinsic demapper LLR per frame, is calculated in the last decoding pass; if it exceeds a pre-defined threshold, , the frame is claimed to be a desired frame.…”

“…This fact inspired the author of the current paper to investigate whether alternate use of different labelings of the same type could bring any benefit to a wireless system. The results, published in [ 10 , 11 ] for 16-QAM and 64-QAM modulation, respectively, showed that the receiver can filter out so-called "foreign frames", which are frames in which the symbols are mapped according to an asymptotically optimal labeling different from the one used at the receiver side. Therefore, it is possible to identify frame recipients using nothing but the receiver-specific labeling map.…”

“…The results presented in [ 10 , 11 ] demonstrate the LABRID receiver’s ability to distinguish between foreign and desired frames in a homogeneous BICM-ID system with either 16-QAM or 64-QAM modulation, in which all stations are LABRID-compatible. This means that all receivers can run iterative decoding and use an appropriate labeling map.…”

The effects of the cross-entropy stopping criterion and quadrature amplitude modulation on iterative turbo decoding performance

“…Most of the research on iterative turbo decoding stopping criteria have utilised the binary phase-shift keying (BPSK) modulation technique [6], [7], [11], [15], which is the simplest form of phase-shift keying. High-speed networks such as long-term evolution (LTE) networks and those based on fifth-generation (5G) technology require high modulation (For example, eight phase-shift keyings (8PSK), 16 phase-shift keyings (16PSK), 16-QAM, 32-QAM, and 64-QAM) to transfer data at a sufficient speed [14], [16], [25]. A higher modulation needs to be integrated into stopping criteria to meet the speed requirements of current LTE applications [14], [16].…”