Spatio-temporal Precoding for Faster-than-Nyquist MISO Transmissions
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Solution Overview
Problem
Existing digital communication systems face challenges in implementing Faster-than-Nyquist (FTN) signaling on Multiple Input Single Output (MISO) channels without requiring complex receivers, as they introduce inter-symbol interference that complicates signal detection.
Innovation Solution
A method and device that use spatio-temporal precoding to compute precoded symbols, accounting for both inter-user and inter-symbol interference, allowing for FTN signaling at a rate higher than the Nyquist rate, thereby enabling efficient data transmission to multiple receivers using known receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If FTN signaling is used to improve bandwidth efficiency, then bandwidth efficiency is improved, but receiver complexity increases due to ISI
Solution Approach 1:
The patent applies preliminary anti-action by computing precoded symbols at the transmitter that pre-compensate for both inter-user interference and inter-symbol interference. The precoding process calculates precoded symbols using channel state information and pulse shape characteristics, then transmits these pre-corrected symbols. This preliminary correction eliminates the need for complex ISI cancellation at the receiver, resolving the contradiction between bandwidth efficiency and receiver complexity.
2Object-affected harmful factors
If precoding is applied to mitigate spatial interference, then spatial interference is reduced, but computational complexity at the transmitter increases
Solution Approach 1:
The patent merges the mitigation of spatial interference and temporal interference into a unified precoding framework. Instead of treating inter-user interference and inter-symbol interference separately, the invention combines both interference types into a single precoding computation that simultaneously addresses both issues. This merging approach reduces overall computational complexity compared to sequential processing of each interference type.
3Productivity
If FTN signaling rate is increased beyond Nyquist rate, then bandwidth efficiency is improved, but inter-symbol interference increases
Solution Approach 1:
The patent applies preliminary action by incorporating the pulse shape characteristics and expected ISI effects into the precoding computation before transmission. The precoded symbols are calculated with knowledge of the FTN signaling rate and pulse shape, pre-compensating for the inter-symbol interference that will occur during transmission. This preliminary compensation allows the system to operate at FTN rates while maintaining signal integrity.
Data Source
AI summary
The invention provides a method and device for sending K data messages simultaneously from a data transmission device to K receivers, over a Multiple Input Single Output, MISO, channel. The transmitter uses a Faster-than-Nyquist signaling rate. By making use of spatio-temporal channel interference model at the transmitter, the benefits of FTN in terms of effective rate and energy efficiency do not come at the expense of increased receiver complexity.