System for reducing the affects of signal fading on received signals
US5191598A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1991 |
| Grant date | Mar 2, 1993 |
| Priority date | — |
| Expiry date | Feb 7, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0204
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Signals in synchronizing sequences and data sequences are transmitted over a fading channel to a Viterbi-receiver. The signals are received by antennas and sampled to received antenna signals (s.sub.in,r (k)). Part channel estimates (h.sub.est,r) for the individual antennas are formed. For Viterbi-analysis, assumed input signals (s.sub.a,r (.DELTA.T.sub.ij,k)) for the data sequence are produced with the aid of the part channel estimates (h.sub.est,r). Part metric values (m.sub.r (.DELTA.T.sub.ij, k)) are formed as a difference between the received antenna signal (s, .sub.in,r (k)) and corresponding assumed input signals (s.sub.a,r (.DELTA.T.sub.ij, k)) for Viterbi state transitions (.DELTA.T.sub.ij). For one state transition there is formed a metric value such as the sum of a metric value ((M(T.sub.j, k-1)) for an old state (T.sub.j) at a preceding sampling time point (k-1) increased with a weighted (K.sub.r) sum of the part metric values (m.sub.r (.DELTA.T.sub.ij, k)) belonging to individual part channel estimates (h.sub.est,r). Corresponding metric values are formed for all state transitions to the new state (T.sub.i) and the smallest of these metric values is chosen in accordanc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.