Hybrid threshold-based selection diversity receivers for efficient resources utilization

In wireless networks, the transmission medium poses several challenges in preserving the Quality-of-Service due to its random nature especially in operational environments with mobility and absence of line-of-sight links between the receiver and the transmitter. On the other hand, confronting the effects of fading channels requires the employment of complex but necessary mechanisms, such as channel equalization and diversity reception and/or transmission, which utilize hardware and channel resources. A common practice, which compromises between resources consumption and performance improvement, is to employ adaptive diversity mechanisms, such as the selection diversity (SD), which represents an attractive solution in various wireless communication scenarios, since it offers relatively low complexity and improved performance. In many practical situations, though, the continuous monitoring of all the available diversity paths, which is mandatory in SD schemes, leads to unnecessary resources consumption (e.g., control channels). In order to alleviate this complexity, we adopt a new adaptive threshold-based SD (t-SD) receiver, where only the current diversity path is used for signal reception as long as its signal-to-noise ratio is above a predefined threshold, otherwise the receiver becomes a pure SD. To this aim a new analytical performance evaluation framework is presented in terms of important statistical metrics, along with a complexity analysis. Numerical evaluated results illustrate how the proposed scheme outperforms other well known schemes in terms of performance and complexity trade-off.