Spread-OFDM Signal Processing for 5G Resource Allocation
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in spectral resource utilization due to peak demand reservations, leading to underutilization, particularly in multiple-access technologies like OFDMA and NOMA, which struggle with peak power consumption and latency in 5G and beyond 5G networks.
Innovation Solution
The implementation of discrete-time spread-OFDM signals with selective spreading code roll-off factors and sparse DFT-s-OFDM code spaces, allowing for power and spectral efficiency optimization through pulse shaping and code-space management, enabling low PAPR and improved frequency diversity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spectral resources are reserved to meet peak demand, then system reliability is improved, but spectral efficiency deteriorates due to underutilization
Solution Approach 1:
The patent implements dynamic resource allocation where the network node adaptively adjusts the number of orthogonal cover codes assigned to different physical resource blocks based on real-time channel conditions and traffic demands. This dynamic approach allows the system to meet peak demand reliably while avoiding spectral waste during low-utilization periods, resolving the contradiction between reliability and spectral efficiency.
Solution Approach 2:
The system changes the parameter of orthogonal cover code allocation dynamically across different physical resource blocks. By varying the number of OCCs assigned to each RB according to channel quality indicators and traffic patterns, the system optimizes both reliability (ensuring adequate resources during peak demand) and spectral efficiency (avoiding over-provisioning during low demand).
2Loss of energy
If conventional OFDMA is used, then spectral efficiency is improved, but peak power consumption increases
Solution Approach 1:
The patent applies local quality by assigning different numbers of orthogonal cover codes to different physical resource blocks based on their specific channel conditions. Users are allocated OCCs selectively in RBs with poor channel conditions, allowing them to transmit at lower power in those specific locations while maintaining overall spectral efficiency. This localized approach reduces peak power consumption without sacrificing spectral efficiency.
3Reliability
If more orthogonal cover codes are allocated, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent implements partial action by allocating orthogonal cover codes selectively rather than uniformly across all physical resource blocks. The network node determines the appropriate number of OCCs for each user in each RB based on channel conditions, providing just enough diversity gain for reliability where needed without unnecessarily increasing device complexity in all locations. This selective allocation maintains reliability while controlling complexity.
Data Source
AI summary
A transmitter in a wireless communication network includes a bits-to-symbol mapper that produces a plurality of data symbols; and a waveform modulator that receives a first discrete-time waveform and at least a second discrete-time waveform that comprises a cyclic shift of the first discrete-time waveform; modulates a first one of the plurality of data symbols onto the first discrete-time waveform and modulates a second one of the plurality of second data symbol onto the second discrete-time waveform, to produce a plurality of modulated discrete-time waveforms; and sums the plurality of modulated discrete-time waveforms to produce a modulated discrete-time signal to be transmitted in the network. The first discrete-time waveform and at least the second discrete-time waveform are multicarrier signals.