Single Antenna Spatial Multiplexing via Delay Offset Precoding
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Solution Overview
Problem
Current wireless communication systems face limitations in efficiently transmitting multiple spatial streams from a single transmitter antenna, as they require multiple antennas at both the transmitter and receiver for spatial multiplexing, which is not feasible in all devices due to space and energy constraints.
Innovation Solution
The proposed solution involves precoding data signals with different multipath components to create offset signals in the delay/Doppler domain, allowing a single transmitter antenna to transmit multiple spatial streams simultaneously by emulating a multi-beam transmission using a single beam, thereby achieving spatial multiplexing without the need for multiple antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spatial multiplexing is implemented using multiple antennas at both transmitter and receiver, then spectral efficiency is improved, but device complexity and hardware requirements increase
Solution Approach 1:
The patent segments the spatial multiplexing function into two parts: the transmitter uses a single antenna with precoding to create virtual multiple-antenna effects, while the receiver uses multiple antennas to separate the spatial streams. This segmentation allows the transmitter to be simplified while maintaining overall system performance.
Solution Approach 2:
The patent creates virtual copies of multiple transmit antennas through precoding techniques. By applying different precoding matrices to the same physical antenna, the system generates signals that appear to originate from multiple spatial locations, effectively copying the functionality of multiple antennas without requiring multiple physical transmit antennas.
2Productivity
If multiple antennas are used at the transmitter for spatial multiplexing, then throughput is improved, but space and energy constraints are violated
Solution Approach 1:
The patent merges the functions of multiple transmit antennas into a single physical antenna by combining multiple spatial streams through precoding. This allows the single antenna to transmit multiple data streams simultaneously by encoding them with different spatial signatures, achieving the throughput of multiple antennas with the hardware of one.
Solution Approach 2:
The single transmit antenna is designed to perform multiple functions: it transmits multiple spatial streams simultaneously, performs precoding operations, and adapts to different channel conditions. This multi-functionality allows the antenna to replace what would traditionally require multiple specialized antennas, reducing energy consumption and hardware complexity.
3Productivity
If traditional spatial multiplexing with multiple antennas is used, then multiple spatial streams can be transmitted, but the solution is not feasible for devices with space constraints
Solution Approach 1:
The patent transitions from spatial dimension to signal processing dimension by using precoding. Instead of physically separating multiple transmit antennas in space, the system separates spatial streams through mathematical transformations in the signal domain. This dimensional change allows multiple streams to be transmitted from a single antenna location, eliminating the need for additional physical space.
Data Source
AI summary
A device includes a wireless interface configured for wirelessly transmitting a signal to a receiver; and a precoder unit configured for obtaining a first data signal to be transmitted and a second data signal to be transmitted; and for performing a first multipath-precoding of the first data signal according to a first set of paths between the device and the receiver to obtain a first precoded signal; and for performing a second multipath-precoding of the second data signal according to a second set of paths between the device and the receiver to obtain and a second precoded signal; wherein the precoder unit is configured for generating the first precoded signal and the second precoded signal such that the second precoded signal is delayed with respect to the first precoded signal at the receiver. The device is configured for transmitting the first precoded signal and the second precoded signal.