Frequency-Domain Preamble With Single-Carrier Data Waveform
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently utilizing frequency-domain waveforms, particularly in channel estimation and data transmission, due to inter-symbol interference and the need for complex equalizers, which can lead to reduced throughput and increased costs.
Innovation Solution
Implementing a frequency-domain preamble based on orthogonal frequency division multiplexing (OFDM) waveforms to facilitate channel estimation, followed by data transmission using a single carrier time-domain waveform, which simplifies receiver design and reduces computational costs by avoiding FFT calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM waveform is used for data transmission, then spectral efficiency is improved, but inter-symbol interference increases and complex equalizers are required
Solution Approach 1:
The transmission is segmented into two distinct parts: an OFDM preamble for channel estimation and a single-carrier body for data transmission. This segmentation allows the system to use OFDM's spectral efficiency for pilot signals while avoiding its inter-symbol interference problems for actual data transmission.
Solution Approach 2:
The waveform type parameter is changed between different portions of the transmission. The preamble uses OFDM parameters (multiple subcarriers, frequency-domain processing) while the body uses single-carrier parameters (time-domain transmission, no FFT required), allowing optimization for different functional requirements.
2Device complexity
If single carrier waveform is used for data transmission, then receiver complexity is reduced, but spectral efficiency decreases
Solution Approach 1:
Channel estimation is performed in advance using the OFDM preamble before the actual data transmission begins. This preliminary action provides the receiver with channel knowledge that simplifies subsequent single-carrier data reception, allowing the system to maintain low complexity while achieving good spectral efficiency.
Solution Approach 2:
The OFDM preamble acts as an intermediary that facilitates the transition from complex OFDM transmission to simple single-carrier reception. It provides the necessary channel information that enables the receiver to efficiently decode the single-carrier data without requiring complex equalization.
3Productivity
If OFDM waveform is used throughout the slot, then throughput is improved, but computational cost increases due to FFT calculations
Solution Approach 1:
The transmission slot is segmented into a preamble portion using OFDM and a body portion using single-carrier modulation. This segmentation allows the system to limit FFT calculations to only the preamble for channel estimation, while the majority of the data transmission uses computationally efficient single-carrier modulation.
Solution Approach 2:
OFDM processing (FFT calculations) is applied partially rather than excessively - only to the extent necessary for channel estimation in the preamble, rather than being applied to the entire data transmission. This partial application maintains throughput while reducing computational cost.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, in a slot, a preamble provided based at least in part on an orthogonal frequency division multiplexing (OFDM) waveform. The UE may perform an estimation operation based at least in part on the preamble. The UE may receive, in the slot, a data transmission via a single carrier time-domain waveform based at least in part on the estimation operation. Numerous other aspects are provided.