Abstract: Polyphase sequence generation is provided for sequences having good aperiodic correlation properties. The sequences can allow lengths not attainable by other types of sequences (such as Frank sequences) and can yield increase merit factors and more desirable peak-to-side-peak ratios (and therefore decreased sidelobe energy) than other sequences (such as Chu sequences). Perfect root-of-unity sequences of lengths up to 32, achieving the minimum phase alphabets and the maximum merit factors and/or peak-to-side-peak ratios, are searched, and the results are tabulated. Comparing the merit factors and peak-to-side-peak ratios of the best search results to other sequences, a common construction pattern of the improved sequences of length 2m2 are obtained. The improved sequences can be utilized in a variety of configurations, including spread spectrum communication, radar, channel estimation, system identification, and/or the like.

Abstract: Sequence generation in wireless communication is provided for sequences having good aperiodic correlation properties. In particular, dual window quasi-Barker sequences are generated that possess at least some properties of Barker sequences. In addition, the sequences can be orthogonal to mitigate multiple access interference. Dual windowing allows the sequences even after being phase modulated by data to be recognized, provided that delay in transmission is large as compared to the correlation zone. In this regard, the sequences can be utilized in quasi-synchronous spread spectrum and/or code division multiple access (CDMA) signal communication to provide orthogonality while substantially eliminating inter-user and inter-symbol interference. In addition, unlike the single window low periodic correlation sequences, system overheads, such as cyclic prefix, need not be utilized in transmission as the data modulation effect can be accounted for by the dual windowing.

Abstract: Polyphase sequence generation is provided for sequences having good aperiodic correlation properties. The sequences can allow lengths not attainable by other types of sequences (such as Frank sequences) and can yield increase merit factors and more desirable peak-to-side-peak ratios (and therefore decreased sidelobe energy) than other sequences (such as Chu sequences). Perfect root-of-unity sequences of lengths up to 32, achieving the minimum phase alphabets and the maximum merit factors and/or peak-to-side-peak ratios, are searched, and the results are tabulated. Comparing the merit factors and peak-to-side-peak ratios of the best search results to other sequences, a common construction pattern of the improved sequences of length 2m2 are obtained. The improved sequences can be utilized in a variety of configurations, including spread spectrum communication, radar, channel estimation, system identification, and/or the like.

Abstract: Methods and apparatus for enabling effective decoding of rate-compatible punctured codes are presented herein. A puncturing component can derive one or more partial puncturing patterns and corresponding decoding matrices/graphs that represent punctured code from a parity check matrix/graph of a mother code and a puncturing pattern specified for the mother code. Further, a rowcombining component can combine rows of the parity check matrix/graph based on the derived one or more partial puncture patterns. Further, the rowcombining component can create at least one decoding matrix/graph to represent the punctured code based on the combined rows. In addition, a selection component can select a decoding matrix/graph from the created at least one decoding matrix/graph that does not contain a girth-4 cycle.

Abstract: Polyphase sequence generation is provided for sequences having good aperiodic correlation properties. The sequences can allow lengths not attainable by other types of sequences (such as Frank sequences) and can yield increase merit factors and more desirable peak-to-side-peak ratios (and therefore decreased sidelobe energy) than other sequences (such as Chu sequences). Perfect root-of-unity sequences of lengths up to 32, achieving the minimum phase alphabets and the maximum merit factors and/or peak-to-side-peak ratios, are searched, and the results are tabulated. Comparing the merit factors and peak-to-side-peak ratios of the best search results to other sequences, a common construction pattern of the improved sequences of length 2 m2 are obtained. The improved sequences can be utilized in a variety of configurations, including spread spectrum communication, radar, channel estimation, system identification, and/or the like.

Abstract: Joint erasure marking Viterbi algorithm (JEVA), decoder schemes, methods, and systems are provided which perform robust trellis decoder techniques. The provided JEVA decoding schemes are shown to be maximum likelihood decoding schemes that find the most likely transmitted code sequence with a set of symbol erasures, without knowledge of the impulsive noise probability distribution function, and can be implemented sequentially such that they are well suited for dynamically changing impulsive noise channels. In addition, the disclosed details enable various refinements and modifications according to decoder and system design considerations. For example, truncated JEVA is provided for continuous transmission and long frame applications.