Anna University

Kbc Research Foundation Pvt. Ltd.

International Business Machines Corporation

Kbc Research Foundation

Srikanth Subramanian

Venkat Venkatsubra

Sarad Ammanat Venugopalan

Kyle R Moser

Ranadip Das

Pedro V Torres

Amit Ranjan Lakra

Sarad Ammanath Venugopalan

Sathish Viswanathan

Methods and systems for detecting a preamble of a data packet in wireless communication systems is provided. To determine a preamble from a received signal, which may include a noise-altered preamble bit sequence, linear feedback shift registers (LFSRs) can be used to generate a count of the received preamble, and the count is compared to pre-generated scores to identify a match. Example methods include for each of a number of different preamble orientations of a preamble, generating a count value based on a comparison of bits of the preamble with a random bit sequence to produce a sequence of count values, and comparing the sequence of count values with m sequences of count values. A sequence of count values is identified that includes a maximum number of matching elements, and the received preamble is determined to be one of the m preambles corresponding to the identified sequence.

Methods and systems for detecting a preamble of a data packet in wireless communication systems

Sub-channels in cells of an Orthogonal Frequency Division Multiple Access (OFDMA) network are formed based on random permutations of a set of subcarrier indices. The random permutations are performed for each cell of the network using a pseudo-random number generator (PRNG) and a shuffle technique. Different initial states of the PRNG are used to generate the random permutation of the subcarrier indices for each cell. In an embodiment, sub-carriers represented by a contiguous group of indices in the random permutation obtained for a cell are assigned to form a sub-channel. Interference diversity for the OFDMA network is thereby improved.

Subchannel formation in OFDMA systems

A network system employs path health information to select an acceptable path between a source node and destination node within an information handling system (IHS) and/or between a source node within one IHS and a destination node within another IHS. One or more switches may connect these two IHSs together. The network system accesses the path health information to determine the availability of paths for communicating between nodes.

Network system using path health information for path selection

Methods and systems for synchronizing wireless transmission of data packets is provided. Signals having a data packet frame format including a preamble (with a pattern of symbol sequences) and data are received, and patterns of symbol sequences are correlated. A first metric can be calculated that is a ratio of an average of the correlation values and an average of a power of the signals. A second metric can be calculated that defines an average of a power of noise in the signals. The methods include determining an approximate division of the preamble and data in the data packet of each signal based on the first and second metrics. The methods further include determining a cross-correlation between versions of a transmitted signal to produce a number of peaks equal to a number of transmit antennas, generating a third metric based on combinations of cross-correlations, and identifying a position of a maximum peak within the third metric as a fine timing offset amount.

Methods and systems for synchronizing wireless transmission of data packets

A method for processing data packets in an interception proxy server without using a Network Address Translation module. A TCP packet received at a router is encapsulated using generic routing encapsulation (GRE). The TCP packet is redirected to a proxy server through a GRE tunnel which includes a redirection rule comprising a local destination IP address and port to be used for traffic passed through the tunnel. When the proxy server receives the TCP packet, the TCP packet is decapsulated. If a flag is set in the payload header of the TCP packet indicating that a redirection rule has been configured for traffic passed through the tunnel, the payload header of the TCP packet is modified according to the redirection rule. The modified TCP packet is then passed to a transmission control protocol of the proxy server.

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Chennai, India

Srikanth Subramanian