Loran phase codes, revisited

Analysis of Cross-Rate Interference Cancelation by Use of a Novel Phase Code Interval in Loran Navigation System

“…Thus, the dimensional vector space changes from N = 4 in one PCI to N = 8, and therefore, the receiver becomes more complicated. In addition, the total phase code is not equal to zero in one period of PCI in the presented phase coding in , and therefore, the continuous wave interface using this course of phase coding along with implementing the phase decoding algorithm and averaging approach does not result in its decrease to zero. In the new phase code proposed in this work, unlike , the total phase code in one PCI is equal to zero.…”

“…Cross‐Rate Interference (CRI) appears in the Loran system when the signals of a chain (the considered chain) with Group Repetition Interval GRI 1 are coincident from the time point of view with another chain with group repetition interval GRI 2 . Exploiting information from Time Of Arrival (TOA) positioning which is affected by CRI causes navigation accuracy to decrease and causes time for cycle selecting and searching to increase in the Loran system . When interference signals overlap with an arbitrary desired signal, the probability of receiving the desired signal declines.…”

“…Although the number of remaining lines is not remarkable, it can cause a significant error in estimating the time. The Loran standard signal analysis in the frequency domain was performed in , and finally, a sequence of phase coding was presented. Such codes in are orthogonal with each other.…”

“…The Loran standard signal analysis in the frequency domain was performed in , and finally, a sequence of phase coding was presented. Such codes in are orthogonal with each other. Thus, the dimensional vector space changes from N = 4 in one PCI to N = 8, and therefore, the receiver becomes more complicated.…”

“…Thus, our proposed course of phase coding yields not only the complete elimination of CRI interference but also significant improvements in the elimination of CWI interference. Furthermore, the new coding vectors, unlike , are not orthogonal. Indeed, these vectors are bi‐orthogonal meaning that the correlation between each pair of phase coding vector is ρ = 0 or ρ = 1.…”