| Project/Area Number |
20K04493
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 21020:Communication and network engineering-related
|
|---|
| Research Institution | Doshisha University |
|---|
Principal Investigator |
程 俊 同志社大学, 理工学部, 教授 (00388042)
|
|---|
| Project Period (FY) |
2020-04-01 – 2024-03-31
|
| Project Status |
Granted (Fiscal Year 2022)
|
| Budget Amount *help |
¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2022: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2021: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
|
|---|
| Keywords | wireless communications / sensor networks / massive random-access / fading channel / slotted ALOHA / density evolution / finite blocklength / fading channels / ランダムアクセス方式 / 電波伝搬特性 / 通信路符号化 / センサネットワーク / 多重接続通信路 |
|---|
| Outline of Research at the Start |
電波伝搬特性を生かしたランダムアクセス方式の研究を行う．大規模密集センサネットワークにおいて，一定時間内に一部のアクティブなセンサは，共通符号を用いてアクセスポイントにランダムにパケットを送信する．送信パケットは，センサからの情報でパケット長が短い．アクセスポイントは，衝突が起こったパケットに対して，各デバイスの電波伝搬特性を推定し，それをデバイス識別情報として用い，混信信号を分離する．本研究では，情報理論，符号理論に基づき，電波伝搬特性を活用した共通符号を提案する．ネットワークの最適化を解析し，有限長伝送の理論限界に近づく，低演算量で実現可能な大規模密集センサネットワークの構築を目指す．
|
| Outline of Annual Research Achievements |
We are progressing according to the original plan in 2022, and achieved the following results.
Irregular Repetition Slotted ALOHA (IR-SA) scheme is an example of unsourced random access communications. It is simple and practical for applications. Over fading channels, however, the limit performances, i.e., theoretical bounds, of the IR-SA are unknown. In 2022, one of our works is to derive two theoretical bounds of IR-SA over fading channels: a maximum a posteriori (MAP) threshold and a converse bound. The MAP threshold is a theoretical upper bound of a practical decoding performance. The converse bound expresses an impossibility threshold to be approached. The bounds are guidelines for practical implementation of IR-SA.
|
| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
As summarized in the Research Achievements section, the research is smoothly progressing according to the original plan in 2022.
For IR-SA scheme over Rayleigh fading channels, we proposed an asymptotic analysis of the decoding performance for systems. First, since an open decoding tunnel exists in an extrinsic information transfer (EXIT) chart, the sum of the two areas below two EXIT curves is smaller than the area of the entire domain. This gives a converse bound of the traffic, which is tight. Second, a coincidence of the belief propagation (BP) EXIT and maximum a posteriori (MAP) EXIT curves makes it possible to derive an MAP threshold of the traffic. Third, a density evolution for a spatially-coupled scheme is formulated and gives a BP decoding threshold of the traffic.
|
| Strategy for Future Research Activity |
Part of this research results in 2022 have been summarized and will be presented in international conferences in 2023 (the extension year).
|
Report
(3 results)
Research Products
(30 results)
