Cooperative Multiuser Relay Communications Employing Hierarchical Modulation
| Autor: | Saransh Malik, Roderick Jaehoon Whang, Huaping Liu, Intae Hwang |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Computer science
business.industry Hierarchical modulation Throughput Radio spectrum Computer Science Applications law.invention Transmission (telecommunications) Relay law Diversity gain Telecommunications link Electrical and Electronic Engineering business Computer Science::Information Theory Computer network |
| Zdroj: | Wireless Personal Communications. 69:1463-1479 |
| ISSN: | 1572-834X 0929-6212 |
| DOI: | 10.1007/s11277-012-0645-z |
| Popis: | Relay-assisted cooperative communications are a promising solution for error-performance improvement and cell coverage extension. However, additional resources such as time slots or frequency bands are required for the relay, which reduce the overall throughput. This paper proposes two cooperative relay schemes that employ hierarchical modulation to overcome this limitation. One scheme is for symmetric downlink communications and the other is for asymmetric downlink communications. These schemes exploit the hierarchical modulation symbols for users in the network and allow the system to transmit two or more independent data streams simultaneously. The proposed schemes reduce the number of transmission phases to the same as conventional schemes without diversity gain. The symbol-error rates of the proposed systems are a function of the distance parameter of hierarchical modulation. By flexibly controlling the distance parameter based on specific scenarios, it allows an extra degree of freedom to guarantee error performance of receivers whose signals undergo different losses. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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