Spreading Sequence Selection for NOMA Interference Reduction
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Solution Overview
Problem
In spread spectrum communication, especially in Non-Orthogonal Multiple Access (NOMA) technology, continuous collision and interference occur when multiple user equipment select the same spreading sequence, leading to de-spreading failures and increased block error rates.
Innovation Solution
User equipment selects different spreading sequences for each symbol from a set of pre-configured sequences to minimize interference, ensuring that at least two symbols use distinct sequences, allowing the base station to correctly de-spread the data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If user equipment selects the same spreading sequence for multiple symbols to simplify transmission, then device complexity is reduced, but continuous collision and interference occur between spread data from different user equipment
Solution Approach 1:
The patent makes the spreading sequence selection dynamic by requiring user equipment to select different spreading sequences for different symbols rather than using a fixed sequence. This dynamic variation across symbols prevents continuous collision and interference while maintaining manageable complexity through predefined selection rules.
Solution Approach 2:
The patent changes the parameter of spreading sequence selection by introducing the constraint that at least two symbols must use different spreading sequences. This parameter change transforms the static sequence selection into a varied selection process, eliminating continuous interference while preserving system simplicity.
2Productivity
If user equipment independently selects spreading sequences from a pre-configured set to reduce signaling overhead, then communication efficiency is improved, but continuous collision and interference occur when multiple user equipment select the same sequence
Solution Approach 1:
The patent applies local quality by allowing user equipment to independently select spreading sequences from a pre-configured set, giving each user flexibility in sequence selection. This local autonomy improves communication efficiency while the additional constraint of using different sequences for different symbols ensures de-spreading accuracy is maintained.
Solution Approach 2:
The patent introduces dynamics into the sequence selection process by requiring variation across symbols. This dynamic approach prevents continuous collision and interference that would otherwise occur with static sequence selection, maintaining both communication efficiency and de-spreading accuracy.
3Reliability
If the base station allocates different spreading sequences for different user equipment to avoid interference, then data transmission accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent implements self-service by enabling user equipment to independently select spreading sequences from a pre-configured set without base station allocation. This autonomous selection reduces signaling overhead while the constraint of using different sequences for different symbols ensures transmission accuracy is maintained through interference avoidance.
4Device complexity
If user equipment uses the same spreading sequence for all symbols to simplify processing, then device complexity is reduced, but block error rate increases due to continuous interference
Solution Approach 1:
The patent applies periodic action by requiring user equipment to vary spreading sequences across different symbols in a periodic manner. This periodic variation prevents continuous interference patterns that would otherwise occur with static sequence usage, maintaining low device complexity while improving data transmission accuracy.
Data Source
AI summary
A method for spread spectrum communication, a user equipment and a base station are provided in embodiments of the present disclosure. The method for spread spectrum communication applied to a user equipment includes: selecting spreading sequences for a plurality of symbols of data to be transmitted in a set of spreading sequences, respectively, wherein spreading sequences selected for at least two symbols are different; spreading the data by using the selected spreading sequences; transmitting the spread data.