Discontiguous Spectrum Subcarrier Allocation for Wireless Systems
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Solution Overview
Problem
Conventional wireless communication systems face challenges in transmitting broadband signals due to fragmented communications frequencies that do not include contiguous segments with wide enough bandwidth, particularly in satellite and terrestrial communications, leading to underutilization of spectrum and unreliable connectivity in densely populated areas.
Innovation Solution
The method involves defining orthogonal subcarriers across a frequency band, distributing available physical subcarriers among discontiguous bandwidth segments, and multiplexing communications signals onto these subcarriers using adaptive modulation and coding (AMC) techniques, including pilot signals and data subcarriers, to efficiently utilize non-contiguous frequency bands for broadband communications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional contiguous frequency bands are used for broadband communications, then spectral efficiency is maintained, but the system cannot utilize fragmented spectrum segments and suffers from bandwidth limitations in densely populated areas
Solution Approach 1:
The patent segments the frequency band into multiple subcarriers that can be independently allocated to different users and services. This allows the system to utilize fragmented discontiguous spectrum segments by assigning subcarriers across non-contiguous frequency regions, thereby improving spectrum utilization flexibility while maintaining reliable broadband communications through distributed frequency diversity
Solution Approach 2:
The patent introduces a new dimension of frequency resource allocation by enabling transmissions across discontiguous frequency bands. Instead of being constrained to contiguous spectrum, the system can allocate resources across multiple separated frequency segments, effectively adding a dimensional flexibility to spectrum utilization that resolves the contradiction between adaptability and reliability
2Productivity
If discontiguous frequency bands are utilized for broadband communications, then spectral efficiency and capacity are enhanced, but system complexity increases due to non-contiguous resource allocation
Solution Approach 1:
By segmenting the frequency band into standardized subcarriers and implementing systematic allocation schemes, the patent manages the complexity of discontiguous resource allocation. The segmented structure allows for efficient resource management through standardized procedures, enabling high data rate capacity across fragmented spectrum while keeping system complexity manageable through structured approaches
Solution Approach 2:
The patent changes the parameter of frequency continuity from contiguous to discontiguous, enabling broader spectrum utilization. By implementing adaptive modulation and coding across these varied frequency segments, the system achieves enhanced productivity and data rate capacity while managing the increased parameter complexity through adaptive techniques
3Loss of energy
If satellite frequencies are reused terrestrially in densely populated areas, then spectrum underutilization is reduced, but interference between satellite and terrestrial signals increases
Solution Approach 1:
The patent segments the frequency resources and applies spatial guardbands to separate satellite and terrestrial communications. By dividing the spectrum into distinct allocated regions and implementing spatial separation techniques, the system reduces spectrum underutilization through terrestrial reuse while managing interference through structured segmentation and guardband implementation
Solution Approach 2:
The patent introduces spatial guardbands as an intermediary mechanism between satellite and terrestrial signals. These guardbands act as buffer zones that mediate the interaction between the two communication systems, enabling frequency reuse while reducing harmful interference through controlled spatial and spectral separation
Data Source
AI summary
Methods of transmitting a plurality of communications signals over a plurality of discontiguous bandwidth segments in a frequency band include defining a plurality (NFFT) of orthogonal subcarriers across the frequency band, defining a plurality (N) of available physical subcarriers from among the orthogonal subcarriers. The available physical subcarriers are distributed among, the plurality of discontiguous bandwidth segments. The methods further include spreading the data symbols for each user and combining the spread data symbols to provide composite data signals. The composite data signals are converted to parallel input signals and interleaved. The interleaved signals are assigned to the N available physical subcarriers. Related transmitters, receivers and communications systems are also disclosed.