Frank Frederiksen’s research while affiliated with Nokia Bell Labs and other places

... Low implementation complexity, the high spectral efficiency of DFT-S-OFDM, stands out as the most acceptable waveforms for 5G accompanying its predecessor OFDM. Investigation on DFT-S-OFDM similar waveforms that are devoid of CP should be on the rise with the aim of encompassing the aforementioned defects, 13 to avoid increase in dramatic complexity of methodologies like generalized frequency division multiplexing (GFDM) or filter bank multicarrier (FBMC) 14,15 making it low LTE compatibility. In this research, zero-tail discrete Fourier transform (ZT DFT-S-OFDM) signals are considered an alternate waveform candidate for conventional CP-OFDM and DFT-S-OFDM modulation. ...

Reference:

Peak to average power ratio reduction of ZT DFT‐S‐OFDM signals using hybrid improved monarch butterfly optimization‐PTS scheme with TR‐clipping scheme

... These methods can be simultaneously implemented based on various use cases. For example, using DRX combined with the PDCCH optimization schemes (i.e., WUS or crossslot scheduling) can reduce power consumption by up to 20% [162]. While those UE-level power-saving techniques in 3GPP Rel 16 offer significant benefits, they also involve trade-offs, as indicated in Table 10. ...

Reference:

Intelligent Heterogeneous Aerial Edge Computing for Advanced 5G Access

... This paper focuses on the 868 MHz ISM band. The occupancy of this particular part of the radio spectrum was the subject of [2,[17][18][19][20]. In [2,17], the traffic intensity and resulting interferences were analyzed on the basis of measurements taken in five different locations. ...

Reference:

Daily Changes in Channel Occupancy in the 868 MHz ISM Band

... The work in [17] has analyzed the listen-before-talk (LBT) mechanism and proposed a new channel access priority for URLLC services, which brings short transmission delay and guarantees the low latency constraint of 1 ms. The authors in [18] have proposed a wireless access technology based on MulteFire, which uses a grant-free uplink scheduling mechanism to reduce the uplink delay. At the same time, URLLC will be interfered with other wireless systems on unlicensed bands which reduces reliability. ...

Reference:

Unlicensed Assisted Ultra-Reliable and Low-Latency Communications

... In fact, this mechanism known as listen-before-talk (LBT) is studied and validated on a SDR platform addressing the coexistence between LTE-LAA systems and wireless local area networks (WLAN) [5]. Moreover, it is also considered for 5G services such as the ultra-reliable and low latency communication (URLLC) [6], thus the incorporation of more advanced features to the current SDR-based platforms is required for the adoption and standardization of unlicensed communication systems. 5G networks have also introduced a massive MIMO technology, where a higher number of antennas at the base station provides a new dimension for opportunistic transmissions in addition to the time-frequency dimension, i.e. the spatial dimension. ...

Reference:

Spectrum Sensing in Software Defined Radio for Cognitive Radio Networks: A Survey

... The downlink physical broadcast channel (PBCH) is used to transmit system information together with PSS and SSS. PSS/SSS and PBCH are known as synchronization signal (SS) blocks, which are sent together with the same periodicity [28][29][30]. In NR-U operations, SS block is transmitted by the gNB in all the deployment scenarios. ...

Reference:

Performance analysis of user power consumption in NR-unlicensed DRX

... (b) Unique Word DFT spread OFDM: Unique Word-spread-OFDM works on similar lines to that of ZT-DFT-s-OFDM, the only difference is that a distinctive signal process is conducted to generate Unique Word (UW) bits that gets appended to the trailing end of each OFDM symbol [11]. On the contrary, several complexity considerations needs to be considered wrt to the transmitter and receiver design. ...

Reference:

EVALUATION OF PAPR REDUCTION ABILITY OF 5G INSPIRED WAVEFORM CANDIDATES

... For cellular networks, HARQ was introduced as part of high-speed packet access in 3G in 2012 and has been a key component in 4 th generation (4G) and 5 th generation (5G) system designs. HARQ has evolved significantly towards supporting 5 and 6 nines of reliability while supporting millisecond level packet latency, for example, the ultra-reliable low latency communications (URLLC) mode in 5G [2]. ...

Reference:

Revisiting Data Recovery Loops in 6G Networks

... If the channel conditions, resource allocation or link adaptation formats change for the retransmission, the RLC segment size may be changed without resegmentation, because the "segment offset" mechanism [52] may indicate new segments with updated segment length relative to their length and position in the original PDU byte-buffer. All this flexibility [46] was not possible in the fixed size PDU solution of the WCDMA/HSPA. ...

Reference:

CONVERGENCE OF PACKET COMMUNICATIONS OVER THE EVOLVED MOBILE NETWORKS; SIGNAL PROCESSING AND PROTOCOL PERFORMANCE

... In addition, conventional LTE BSs require synchronization of uplink and downlink switching points, otherwise, the disparity in transmit power between the BS and the mobile user equipment (MUE) may lead to irreconcilable cross-link interference. However, this is not the case for pico BSs in HetNets, as their transmit power is very close to that of the MUE, which allows pico BSs to independently adjust their uplink and downlink switching points to better adapt to the services they carry [12], [13]. These new features provide strong grips on scheduling the network at a finer granularity but also bring challenges that more complex factors inevitably have to be taken into account when designing scheduling policies. ...

Reference:

User Association and Channel Allocation in 5G Mobile Asymmetric Multi-band Heterogeneous Networks