| 摘要 |
<p>Method and arrangement for rapidly controlling the frequency of a radio-receiver receiving signal-sequences subjected to interference. The signal-sequence is sampled into signal-points (ET) intended for analysis, and a Viterbi-algorithm (10) is adapted (12, 13) by adaptation signals (U1K). A data-sequence of the signal-sequence is Viterbi-analyzed for determining its bit-sequence (S1). According to the invention the signal-point (E¿T?) is branched-up to one branch-signal point (ET) for each state of the Viterbi-algorithm (10). Each branch-signal point is phase-shifted (20) to a corrected signal-point (ET,1) and compared (21) with its adaptation signal (U1?K¿), having separate (K) points. Distances (ΔS¿T,1?K) and angular deviations (Δø¿T,1?K) are calculated between the corrected signal-point (E¿T,1?) and the adaptation-signal (U1?K¿) points. A transition (K1) is selected through the Viterbi-algorithm (10), and the corresponding angular deviation (Δø¿T,1?K) is selected (22). Successively selected angular deviations (Δø¿T,1?K) are processed (22) to a phase correction signal (V) for successively incoming branch-signal points (E¿T?). Remaining states are phase corrected correspondingly.</p> |
