In wireless cellular networks a user equipment can be scheduled for uplink transmission only if the timing is correctly synchronized. Hence, a dedicated channel must be established, i.e. the Physical Random-Access Channel (PRACH), which has a key role as interface between the non-synchronized users’ equipment and the uplink orthogonal transmission scheme. Due to the stringent requirements in terms of delay and influence of noise and multipath fading on the signal detection, the design of a robust PRACH receiver is a critical issue. Moreover, with the introduction of new type of services in fifth generation (5G) New Radio (NR) systems, such as ultra-reliable low-latency communications or machine-type communications, and with the need for mechanisms that are able to dynamically adapt to the changing environment, the design of a robust PRACH receiver is a priority but, at the same time, it opens the way to the development of new solutions. The performance of preamble detection in PRACH worsens when channels become more time dispersive. In order to guarantee an acceptable performance for most of users in a cell, in this paper we provide an improved PRACH receiver design that reduces the combined effect of different error events that determine the total missed detection probability. Considering the difficulty of achieving an accurate detection in some scenarios, a new robust three-step approach is proposed to overcome the issues of conventional PRACH signal detection. It is shown that the proposed approach outperforms the traditional peak detection one when the time-dispersion of the channel increases. The benefits of the proposed solution are demonstrated by means of Monte Carlo simulations.

在无线蜂窝网络中，仅当定时正确同步时，才可以调度用户设备进行上行链路传输。因此，必须建立专用信道，即物理随机接入信道（PRACH），其具有作为非同步用户设备与上行链路正交传输方案之间的接口的关键作用。由于在延迟以及噪声和多径衰落对信号检测的影响方面有严格的要求，因此，鲁棒的PRACH接收机的设计是一个关键问题。此外，随着第五代（5G）新型服务的推出，新无线电（NR）系统（例如超可靠的低延迟通信或机器类型的通信）以及对能够动态适应的机制的需求适应不断变化的环境 稳健的PRACH接收机的设计是当务之急，但同时，它为开发新解决方案开辟了道路。当信道变得更加分散时间时，PRACH中的前同步码检测性能会变差。为了保证小区中大多数用户可以接受的性能，本文提供了一种改进的PRACH接收机设计，该设计减少了确定总漏检概率的不同错误事件的综合影响。考虑到在某些情况下实现精确检测的困难，提出了一种新的鲁棒三步法来克服常规PRACH信号检测的问题。结果表明，当信道的时间色散增加时，该方法优于传统的峰值检测方法。