Zero excess bandwidth modulation
US7616701B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 2004 |
| Grant date | Nov 10, 2009 |
| Priority date | — |
| Expiry date | Jan 30, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/497
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
ZEB (zero excess bandwidth) modulation. The modulation rate of a signal is increased to the entirety of a communication channel's available bandwidth. Spectral zeroes at the edges of the available bandwidth now coincide with spectral zeroes at the edges of the Nyquist band and lead to ISI (intersymbol interference), which cannot be eliminated by equalization. Thus, in a ZEB system intersymbol interference (ISI) is intentionally allowed and dealt with by the known technique of TH (Tomlinson-Harashima) precoding. Comparison of conventional zero-ISI systems with ZEB systems, both exhibiting identical transmit spectra with finite spectral roll offs towards the edges of the available bandwidth, illustrate significant gains in channel throughput achievable by the ZEB systems. Similar gains can hardly be achieved by more sophisticated channel coding for zero-ISI systems. For ZEB systems an effective spectral shaping involving a simple infinite impulse response (IIR) of the overall channel is proposed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.