Distributed LTF Tone Mapping Under 6 GHz PSD Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication devices operating in the 6 GHz band face power spectral density (PSD) limits that reduce communication range and packet detection capabilities, necessitating a solution to enhance transmit power without exceeding these limits.
Innovation Solution
Implementing distributed tone plans for long training fields (LTFs) in PPDU transmissions, allowing noncontiguous subcarrier allocation to increase overall transmit power while adhering to PSD constraints, and optimizing LTF sequences to reduce peak-to-average power ratio (PAPR) for accurate channel estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If PSD limits are imposed on 6 GHz band transmissions, then interference to other services is reduced, but communication range and packet detection capabilities deteriorate
Solution Approach 1:
The patent segments the frequency spectrum into noncontiguous subcarrier groups (distributed tone plans) rather than using contiguous allocations. This segmentation allows the transmit power to be distributed across multiple separated frequency resources, enabling the system to comply with PSD limits while achieving higher overall transmit power through multiple subcarrier transmissions, thereby extending communication range without causing excessive interference to any single frequency band.
2Object-affected harmful factors
If PSD limits are imposed on 6 GHz band transmissions, then interference to other services is reduced, but packet detection capabilities deteriorate
Solution Approach 1:
The patent divides the transmission into multiple noncontiguous subcarrier segments that can be detected independently or collectively. This segmentation allows receivers to accumulate energy across multiple distributed tones, improving packet detection capability while maintaining compliance with PSD limits that reduce interference to other services.
3Power
If distributed tone plans are used for LTF transmissions, then overall transmit power is increased within PSD limits, but complexity of tone mapping increases
Solution Approach 1:
The patent segments the LTF transmission across multiple noncontiguous subcarrier groups using distributed tone plans. This segmentation enables the system to increase overall transmit power by distributing energy across multiple frequency resources while complying with PSD limits, despite the increased complexity of tone mapping operations.
4Measurement precision
If LTF sequences are optimized to reduce PAPR, then channel estimation accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent changes the parameters of LTF sequences by optimizing them to reduce peak-to-average power ratio (PAPR). This parameter optimization improves channel estimation accuracy by reducing signal distortion, though it increases computational complexity in the sequence generation and optimization processes.
Data Source
AI summary
This disclosure provides methods, devices and systems for increasing the transmit power of wireless communication devices operating on power spectral density (PSD)-limited wireless channels. Some implementations more specifically relate to LTF designs that support distributed transmissions. In some aspects, a transmitting device may obtain a sequence of values representing an LTF of a PPDU and may map the sequence of values to a number (N) of noncontiguous subcarrier indices of a plurality of subcarrier indices spanning a wireless channel according to a distributed tone plan. In some implementations, the transmitting device may modulate the sequence of values on N tones, representing a logical RU, and map the N tones to the N noncontiguous subcarrier indices, respectively. In some other implementations, the sequence of values may be obtained based on relative locations of the N noncontiguous subcarrier indices in the wireless channel.