Mobile data traffic has grown substantially owing to the widespread use of data-hungry devices such as smart handsets and laptops. This has encouraged researchers and system designers to develop more efficient network designs. The authors review the technologies that can support speeds of multiple Gbps for future fifth-generation (5G) networks. They examine the many challenges, problems, and questions that arise in the research and design stage, and conclude that the anticipated high-traffic demands and low-latency requirements stemming from the Internet of Things (IoT) and machine-to-machine (M2M) communications can be met only with radical changes to the network paradigm. These include harnessing the millimeter-wave band for the dense deployment of small cells. Future wireless systems will include myriad smart features and applications to make 5G the most intelligent and dominant wireless technology thus far.

Peak-to-average power ratio (PAPR) is a major drawback in most multi-carrier communication techniques such as orthogonal frequency division multiplex system (OFDM). OFDM consists of lots of independent modulated subcarriers, as a result the amplitude of such a signal can have very large values. These large peaks increase the amount of intermodulation distortion resulting in an increase in the error rate. The PAPR of an OFDM signal can be reduced in several ways: selective mapping, Golay sequences, cyclic coding, clipping and filtering, and multiple signal representation techniques. The authors have improved the performance of the OFDM system by using low-density parity-check (LDPC) codes as an alternative to turbo coding in mitigating the PAPR problem which has been used in the pervious works of the authors. The authors present the design for the proposed (LDPC) code technique that achieves good error correction performance and is used to lower the PAPR in a multiple-input multiple-output OFDM system. The simulation results show that 6–60% reduction in PAPR over current values in the literature can be achieved depending on the system type.

Inter cell interference (ICI) is a major challenge that degrades the performance of mobile systems, particularly for cell-edge users. This problem arises significantly in the next-generation system, as the trend of deployment is with high densification, which yields an ultra-dense network (UDN). One of the challenges in UDN is the dramatic increase of ICI from surrounding cells. A common technique to minimize ICI is interference coordination techniques. In this context, the most efficient ICI coordination is fractional frequency reuse (FFR). This paper investigates the FFR in UDN millimeter wave network at 26-GHz band. The focus is on dense network with short inter site distance, and higher order sectorisation (HOS). The metrics used in frequency reuse is the signal to interference plus noise ratio rather than the distance, as the line of sight in millimeter wave can be easily blocked by obstacles even if they are in close proximity to the serving base station. This paper shows that FFR can improve the network performance in terms of per user cell-edge data throughput and average cell throughput, and maintain the peak data throughput at a certain threshold. Furthermore, HOS has a potential gain over default sectored cells when the interference is carefully coordinated. The results show optimal values for bandwidth split per each scenario in FFR scheme to give the best tradeoff between inner and outer zone users performance.