Duplicate Transmission via DCM for PSD-Limited Wireless Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication technologies face challenges in efficiently transmitting data to multiple users while maintaining high throughput and overcoming power spectral density (PSD) limitations in wireless channels.
Innovation Solution
The method involves generating a physical layer (PHY) convergence protocol (PLCP) protocol data unit (PPDU) that includes user data for multiple users, with bandwidth split information and duplicate transmission information. This PPDU is mapped using a dual carrier modulation (DCM) scheme across multiple tones and resource units (RUs), allowing for duplicate transmissions to increase transmit power without exceeding PSD limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If duplicate transmission is used to increase transmit power, then the signal-to-interference-plus-noise ratio (SINR) is improved, but the power spectral density (PSD) limits are exceeded
Solution Approach 1:
The patent segments the transmission bandwidth into multiple resource units (RUs), with each RU carrying a duplicate copy of the user data. By dividing the total bandwidth into separate RUs and distributing the duplicate transmissions across these segments, the system achieves the SINR benefits of duplication while keeping the power density within PSD limits through frequency dispersion.
Solution Approach 2:
The patent transitions from a single-carrier transmission approach to a multi-carrier approach by mapping duplicate data copies across multiple RUs in the frequency domain. This dimensional expansion from one carrier to multiple carriers allows the system to achieve transmit power enhancement without exceeding PSD limits, as the power is distributed across multiple frequency dimensions rather than concentrated in a single carrier.
2Length of moving object
If multiple resource units are used for duplicate transmissions, then the effective range is extended, but the device complexity increases
Solution Approach 1:
The patent employs a universal dual carrier modulation (DCM) scheme that can handle multiple users and multiple RUs using the same fundamental mapping approach. The DCM mechanism serves multiple functions: it creates duplicate copies of data, distributes them across RUs, and enables both single-user and multi-user transmissions. This multi-functionality reduces the need for separate complex mechanisms for each transmission scenario.
Solution Approach 2:
The patent utilizes parameter changes in the resource unit allocation and bandwidth splitting to manage complexity. By dynamically adjusting the number of RUs, the bandwidth distribution, and the mapping parameters based on the number of users and channel conditions, the system achieves extended effective range while adapting the complexity to match the actual transmission requirements rather than always operating at maximum complexity.
3Productivity
If bandwidth is split across multiple RUs, then spectral efficiency is improved, but the transmission time increases
Solution Approach 1:
The patent ensures continuity of useful action by transmitting duplicate copies of user data simultaneously across multiple RUs rather than sequentially. All RU transmissions occur in parallel within the same time slot, maintaining continuous and efficient utilization of the wireless medium. This parallel transmission approach preserves spectral efficiency while avoiding the time penalty that would result from sequential transmission of duplicate copies.
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 tone mapping techniques and packet designs that support duplicate (or “DUP mode”) transmissions to multiple users. In some implementations, an access point (AP) may transmit a PPDU that includes first user data and second user data, where at least the first user data is transmitted in a DUP mode. As such, the first user data may be mapped to a number (N) of tones spanning a first RU in accordance with a dual carrier modulation (DCM) scheme, and a duplicate copy of the first user data may be mapped to N tones spanning a second RU in accordance with the DCM scheme. In some implementations, the second user data also may be transmitted in a DUP mode.