Orthogonal OFDM Mapping to Extend MIMO Radar Sensing Range
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Solution Overview
Problem
The MIMO-OFDM radar waveform reduces the maximum sensing range by a factor of N due to subcarriers being mapped onto each transmit antenna at periodic intervals, leading to poor radar sensing performance.
Innovation Solution
Perform spectrum spreading on to-be-transmitted data using K orthogonal sequences to obtain orthogonal data matrices, map these matrices onto different frequency division multiplexing OFDM subcarriers, and apply inverse fast Fourier transform (IFFT) processing to obtain OFDM time domain signals, which are then transmitted through separate transmit antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If subcarriers are mapped onto different transmit antennas at periodic intervals to implement mutual orthogonality, then orthogonality between transmit antennas is achieved, but the maximum sensing range is reduced by N times
Solution Approach 1:
The patent changes the mapping parameters of subcarriers onto transmit antennas from periodic intervals to a comb-like distribution pattern. Specifically, subcarriers are mapped according to the formula: subcarrier index = k + m×N, where k ranges from 0 to N-1 for different transmit antennas. This parameter transformation maintains orthogonality while extending the sensing range by reducing the interval between subcarriers on the same antenna from N intervals to 1 interval.
2Reliability
If the quantity of periodic intervals of mapped subcarriers is determined by the quantity of transmit antennas, then orthogonality is maintained, but radar sensing performance deteriorates
Solution Approach 1:
The patent introduces asymmetric subcarrier distribution across transmit antennas. Instead of symmetric periodic mapping where each antenna gets equally spaced subcarriers, the comb-like mapping creates an asymmetric pattern where subcarriers are densely packed on each antenna (interval of 1) while maintaining overall orthogonality through the mathematical relationship subcarrier index = k + m×N. This asymmetric distribution improves radar sensing performance while preserving orthogonality.
Data Source
AI summary
This application discloses a data transmission processing method and apparatus, a communication device, and a storage medium. The data transmission processing method includes: performing, by a transmit end, spectrum spreading on to-be-transmitted data through K orthogonal sequences, to obtain K orthogonal data matrices; the transmit end maps the K orthogonal data matrices onto different frequency division multiplexing OFDM subcarriers, to obtain K first OFDM signals, where the first OFDM signals are spectrum spreading data matrix OFDM signals; performing, by the transmit end, inverse fast Fourier transform IFFT processing on a kth first OFDM signal among the K first OFDM signals, to obtain a kth first OFDM time domain signal; and the transmit end maps the kth first OFDM time domain signal onto a kth transmit antenna, and transmits a first data signal through the kth transmit antenna.