Cellular Network Coverage via Dynamic UE Power and Beam Sweeping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 5G cellular network deployments face challenges in expanding coverage, particularly in rural areas, due to limitations in link budgets and signal-to-interference-plus-noise ratio (SINR) at cell edges, which affect Voice over Internet Protocol (VoIP) and enhanced Mobile Broadband (eMBB) services, especially in large cells where thermal noise dominates.
Innovation Solution
The method involves increasing the user equipment (UE) transmission power by determining the instantaneous transmit power level based on UE capabilities, time-frequency opportunities, and modulation and coding schemes, using DFT-S-OFDM waveform with pi/2 BPSK modulation, and enhancing channel estimation through DMRS techniques to improve SINR and coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If UE transmission power is increased to extend coverage distance, then coverage area is improved, but device power consumption increases and maximum power limits are reached
Solution Approach 1:
The patent implements periodic beam sweeping where the base station transmits reference signals in different directional beams across multiple time slots. This periodic action allows the UE to measure and report channel quality for different beams, enabling the system to select optimal beams for data transmission without requiring continuous high power transmission in all directions, thus extending coverage while managing power consumption.
Solution Approach 2:
The patent dynamically adjusts transmission parameters including beam direction, modulation and coding scheme (MCS), and transmit power based on measured channel conditions. By changing these parameters adaptively, the system optimizes the trade-off between transmission distance and power consumption, allowing extended coverage when needed while reducing power consumption under favorable conditions.
2Area of stationary object
If cell size is increased to reduce base station density, then deployment cost is reduced, but SINR at cell edge deteriorates
Solution Approach 1:
The patent segments the downlink transmission into multiple directional beams, each covering a specific spatial sector. By dividing the overall coverage area into multiple beam segments and selecting the best beam for each UE based on channel measurements, the system maintains high SINR at cell edges while supporting large cell areas, avoiding the need for dense base station deployment.
Solution Approach 2:
The patent applies different transmission qualities to different spatial directions through beamforming. Each beam is optimized for its specific direction with appropriate power allocation and modulation schemes. This local optimization ensures that UEs at cell edges in favorable beam directions achieve sufficient SINR, enabling larger cell sizes without uniformly degrading edge performance.
3Reliability
If beam sweeping is performed to improve directional SINR, then cell edge SINR is improved, but transmission overhead increases
Solution Approach 1:
The patent implements partial beam sweeping where not all possible beam directions are transmitted in every time slot. Instead, a subset of beams is swept periodically, and the system uses interpolation and prediction to infer channel conditions for non-transmitted beams. This partial action reduces the overhead of beam sweeping while still achieving sufficient cell edge SINR through selective beam transmission.
4Power
If DFT-S-OFDM waveform with pi/2 BPSK modulation is used to reduce PAPR, then maximum UE transmit power is increased, but data rate capability is reduced
Solution Approach 1:
The patent dynamically selects between different waveforms (DFT-S-OFDM and CP-OFDM) and modulation schemes based on channel conditions and service requirements. DFT-S-OFDM with pi/2 BPSK is used when maximum power transmission is needed for coverage extension, while CP-OFDM with higher-order modulations is used when data rate is the priority and channel conditions permit. This dynamic adaptation resolves the trade-off between power capability and data rate.
Data Source
AI summary
Embodiments of the present disclosure are related, in general to communication, but exclusively related to methods and systems for improving coverage of a cellular network. The method comprising obtaining a transmission power capability of a user equipment (UE), and determining a time-frequency opportunities allocated to the UE and a modulation and coding scheme (MCS) associated with the UE. Thereafter, indicating an increase in the instantaneous transmit power level to the UE based on the transmission power capability of the UE, the time-frequency opportunities and the associated MCS. The method also comprises obtaining the number of Resource Elements (REs) available for PUSCH transmission. A Transport Block Size is obtained for the REs obtained and is transmitted by adding Cyclic Redundancy Check. The procedure also includes the usage of uplink symbols in special slots. The method also comprising the usage of Reference Symbols across the transmission opportunities based on the UE capability.