Jia-Yin Wang

On constructing trellis codes with large free distances and low decoding complexities

We propose a trellis-coding scheme for which large free distances and low decoding complexities can be easily achieved. The proposed trellis-coding scheme is a generalization of the trellis-coding scheme proposed by Hellstern (1993). With the proposed trellis-coding scheme, we have the flexibility of controlling the decoding delay.

On block-coded modulation with interblock memory

Block-coded modulation with interblock memory (BCMIM) is a variation of block-coded modulation (BCM) which is designed for multilevel coding. By providing interblock memory between adjacent blocks, the coding rate of a BCMIM scheme can be increased without decreasing the minimum squared Euclidean distance (MSED) as compared to the original BCM. In an early version of BCMIM, interblock coding is provided only between the first two coding levels of adjacent blocks. In this paper, we design BCMIM with a more general form for which interblock coding can be introduced among many coding levels. In this way, we can further increase the coding rate of BCMIM without decreasing the MSED. We provide many examples to show the advantages of BCMIM with the general form. Most of the examples are designed based on multidimensional signal sets, since a multidimensional signal set can provide more coding levels than a two-dimensional (2-D) signal set.

An efficient roll call system for a smart phone

In this paper, we propose a new efficient roll call system, which combines the conveniences of smart phones and Google spreadsheet to manage attendance records. The list of names can be downloaded from a Google spreadsheet and the attendance records can be synchronized to the spreadsheet table. The system provides traditional name check method, smart Mandarin phonetic input method, and NFC scan method for a fast roll call. In addition, for a large group, the roll call task can be done by using several mobile phones simultaneously to increase the roll call efficiency.

A trellis coded modulation scheme with a convolutional processor

We propose a new trellis coded modulation (TCM) scheme. The proposed TCM is encoded by employing the encoder of a convolutional code C, which is followed by a convolutional processor and a signal mapper. Large free distances can be easily achieved for the proposed TCM. The decoding can be implemented by using the trellis for the convolutional code C with some feedback information.

A multilevel and single-stage trellis coded modulation scheme

We propose a very powerful trellis coded modulation (TCM) scheme which has the structure of multilevel and single-stage coding. For the proposed TCM scheme, the encoder consists of a binary convolutional encoder which is followed by a multilevel delay processor and a signal mapper. By computer search, we find many useful TCM systems which are good for AWGN channels.