Abstract: Mobile devices, mobile device systems and methods applying to mobile devices are provided that employ intelligent agents in combination with a wide array of remote utilities and information sources to facilitate improving a mobile device user's experience. By collecting contextual information from numerous information sources related to the mobile device user's context, more accurate and optimized determinations and/or inferences are formed relating to which remote utilities to make available to the mobile device user. This facilitates less confusion for the user in selecting desired mobile device content, services, and/or applications. The devices, systems, and methodologies also provide for an improved user experience in an open remote utility provider model.

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: Providing for soft error decoding for wireless relay networks is described herein. By way of example, a wireless node in a wireless relay network can receive a direct signal from a source node, and can receive a forwarded version of the source signal from a relay node. An information flag included with the forwarded version is referenced to determine whether the relay node property received the source signal. If the relay node received the source signal with error, and a destination node received the source signal with error, soft decision information can be generated from the forwarded version of the source signal and employed to assist with decoding of the source signal at the destination node. The soft-decision information improves end-to-end performance of the wireless relay system, while mitigating complexity and bandwidth requirements for the relay node as compared with conventional signal decoding techniques.

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.

Abstract: System and methodologies for reduced-complexity signal detection and decoding in a wireless communication system are provided herein. Systems and methodologies presented herein can utilize a relaxed form of the Lenstra-Lenstra-Lovasz (LLL) lattice reduction algorithm to reduce the complexity of lattice reduction operations in the context of MIMO detection. Additional systems and methodologies presented herein can apply lattice reduction in the context of a maximum likelihood (ML) detector for spherical or elliptical lattice space-time (LAST) codes.

Abstract: A wireless network system and corresponding methodologies that operates in a user cooperative communication system is provided. In operation, the system either combines packets transmitted from a direct channel with packets transmitted from and a relay channel, or uses erroneously relayed packets to assist decoding a direct packet.

Abstract: Systems, methods, and computer-readable media for determining long binary sequences having low autocorrelation functions using evolutionary processes are disclosed. Biphase sequences are found with low peak sidelobe values meeting a predetermined criterion, e.g., threshold low auto-correlation function, including application of semidefinite programming in connection with determining an initial population, and evolving the population with an evolutionary algorithm to bits of the biphase sequences including bit flipping. The found biphase sequences can be communicated to a variety of applications, including wireless communications technologies.

Abstract: System and methodologies for reduced-complexity signal detection and decoding in a wireless communication system are provided herein. Systems and methodologies presented herein can utilize a relaxed form of the Lenstra-Lenstra-Lovasz (LLL) lattice reduction algorithm to reduce the complexity of lattice reduction operations in the context of MIMO detection. Additional systems and methodologies presented herein can apply lattice reduction in the context of a maximum likelihood (ML) detector for spherical or elliptical lattice space-time (LAST) codes.

Abstract: Mobile devices, mobile device systems and methods applying to mobile devices are provided that employ intelligent agents in combination with a wide array of remote utilities and information sources to facilitate improving a mobile device user's experience. By collecting contextual information from numerous information sources related to the mobile device user's context, more accurate and optimized determinations and/or inferences are formed relating to which remote utilities to make available to the mobile device user. This facilitates less confusion for the user in selecting desired mobile device content, services, and/or applications. The devices, systems, and methodologies also provide for an improved user experience in an open remote utility provider model.

Abstract: A method for sensing channel availability in a wireless network includes receiving a measurement request message which includes a channel interval list. A first channel interval in the list includes information associated with a first starting channel number, a first number of channels, and first linkage information of the channel interval list. The method includes processing information associated with the message, generating a first list of contiguous channels, and performing at least first channel measurement to determine a first channel availability for each of the first list of contiguous channels. The method also includes determining whether the channel interval list further includes a second channel interval that needs to be processed based on at least first linkage information, and if needed, generating a second list of contiguous channels and performing at least second channel measurement to determine a second channel availability for each of the second list of contiguous channels.

Abstract: Mobile devices, mobile device systems and methods applying to mobile devices are provided that employ intelligent agents in combination with a wide array of remote utilities and information sources to facilitate improving a mobile device user's experience. By collecting contextual information from numerous information sources related to the mobile device user's context, more accurate and optimized determinations and/or inferences are formed relating to which remote utilities to make available to the mobile device user. This facilitates less confusion for the user in selecting desired mobile device content, services, and/or applications. The devices, systems, and methodologies also provide for an improved user experience in an open remote utility provider model.

Abstract: An iterative decoder comprising a transconductance amplifier, a sampler, a Min-Sum decoder, and an early determination module is provided. The transconductance amplifier outputs a current proportional to the voltage of the coded bit stream. The sampler converts the amplified current into a plurality of currents and stores the sampled currents in a plurality of buffers. The Min-Sum decoder receives parallel currents, wherein currents represent the message of each variable node. The Min-Sum decoder exchanges the message of variable nodes and check nodes iteratively and outputs a set of decode codewords according to the possibilities. The early terminating module stops the iterative decoding when the decoded codeword converged.

Abstract: A wireless network system and corresponding methodologiesthat operates in a user cooperative communication system is provided. In operation, the system either combines packets transmitted from a direct channel with packets transmitted from and a relay channel, or uses erroneously relayed packets to assist decoding a direct packet.

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: Spectrum sensing in wireless communications is provided to identify utilized and/or unutilized frequency bands reserved for primary users using a cyclostationary beamforming approach. An adaptive cross self-coherent restoral (ACS) algorithm can be utilized to extract signals of interest (SOI) at unique cycle frequencies related to primary and/or secondary users from an antenna array measurement. Based on the SOI, one or more users of the spectrum can be identified or the spectrum can be regarded as vacant; this can be based on lobe identification in the frequency spectrum of the SOI, in one example. This mechanism is less complex than traditional cyclic spectrum analysis methods. The cyclostationary beamforming based approach is more effective than the energy detection method. Also, the need for quiet periods in spectrum sensing is eliminated when using this mechanism such that signals can be transmitted simultaneously with receiving signals over the antenna array.

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: System and methodologies for amplifier gain control in a communication system are provided herein. By leveraging similarities between the distribution of received signal samples in an MB-OFDM system and a Gaussian distribution, various algorithms described herein can be utilized to perform fast and low-complexity amplifier gain tuning. Received signal strength indication information corresponding to analog signal samples and/or digital signal samples obtained from an analog to digital converter are analyzed to obtain a signal energy distribution. The obtained signal energy distribution is then compared to a reference Gaussian distribution to adaptively tune an associated amplifier gain.

Abstract: A training-based channel estimation technique is provided to estimate channel state information for MIMO systems that is highly energy efficient and optimal in terms of Cramér-Rao lower bound (CRLB). The technique employs loosely synchronized (LS) codes or shifted LS codes. The codes can be generated using a fast Golay correlator and an efficient Golay correlator. A low-complexity implementation is also provided.

Abstract: System and methodologies for low-distortion index assignment for quantization are provided herein. Various aspects described herein utilize a graph theoretic approach for determining an index assignment mapping between a quantization codebook and a signal constellation by employing a variation of the subgraph isomorphism problem. The graph theoretic index assignment algorithms described herein allow efficient determination of index assignment mappings for both binary and non-binary quantization schemes. Further, the topological structure of a signal constellation can be exploited to simplify the set of subgraphs to be searched in select cases. Various aspects described herein can additionally be utilized to determine index assignment mappings for space-time block codes in a multiple-input multiple-output wireless communication system.