An overview of downlink radio resource management for UTRAN long-term evolution

A Flexible Frame Structure for 5G Wide Area

“…Secondly, although not shown in Fig. 3, the proposed frame structure also allows users to be scheduled on non-consecutive frequency blocks to benefit from frequency domain scheduling diversity as also known from LTE [8].…”

“…low cost MTC devices to be instructed to only monitor and operate on part of the bandwidth, which will also be favorable from a terminal energy consumption point of view. This is contrary to LTE, where the UEs need to monitor the full carrier bandwidth as the PDCCH is transmitted on full bandwidth [8].…”

“…This is possible due to the in-resource position of the CCH, which allows using beamforming for both the CCH and the corresponding downlink data transmission in case of single stream transmission, as the same set of reference symbols are applicable for channel estimation (and coherent demodulation) for those PHY channels. In LTE, the PDCCH is transmitted with open loop transmit diversity mode, due to the time-wise disjoint position of the CCH (PDCCH) and data (PDSCH), where common reference symbols (CRS) are used for both the PDCCH and PDSCH transmissions [8]. In LTE-A there is support for dedicated reference symbols for the PDSCH demodulation when using Transmission Mode 9, while the PDCCH is still relying on common reference symbols.…”

“…As an example, if cell A mutes a certain set of its time-frequency domain resources, then the users that the neighboring cell B schedules on that set of time-frequency domain resources will experience improved SINR for both the CCH and the data reception. The same flexibility for ICIC is not possible for LTE due to strict time-division of PDCCH and data in each subframe, where the PDCCH transmission is distributed over the full cell bandwidth [8], [12].…”

“…The corresponding relation between physical (PHY) layer control and data channels is outlined and numerical results are presented. Throughout the paper the LTE 4G standard [7]- [8] is used as our reference for motivating and quantifying the benefits of the new 5G frame structure.…”