Abstract: A wellhead for subsea use and a method of making same where the wellhead is constituted by a body having a bore (3) therethrough and at least one side bore (9, 11) for provision of fluid communication through the wall of the wellhead (1), and where the wellhead (1) includes a pipe hanger (30) provided with a bore (34) therethrough and a side bore (36) for provision of fluid communication between a tubing string (9?) connected to the pipe hanger (30) and one of the side bores (9) of the wellhead (1), where the wellhead (1) is provided with at least one internal safety valve (42, 44) arranged to be able to shut off fluid communication through the wellhead.

Abstract: Methods and apparatus for enhancing estimations of channel response in a wireless communication system are discussed. As an example, a method can comprise: selecting a selected channel from among one or more channels in the communication system; determining, for the selected channel, an initial channel estimate comprising a sequence of frequency-domain samples; determining a phase slope of the initial channel estimate; generating a flat-phase channel estimate by removing the phase slope from the initial channel estimate; and generating an enhanced channel estimate for the selected channel by applying a smoothing function to the flat-phase channel estimate. Other aspects, embodiments, and features are also claimed and described.

Abstract: Techniques for performing detection and decoding at a receiver are described. In one scheme, the receiver obtains R received symbol streams for M data streams transmitted by a transmitter, performs receiver spatial processing on the received symbols to obtain detected symbols, performs log-likelihood ratio (LLR) computation independently for each of D best data streams, and performs LLR computation jointly for the M?D remaining data streams, where M>D?1 and M>1. The D best data streams may be selected based on SNR and/or other criteria. In another scheme, the receiver performs LLR computation independently for each of the D best data streams, performs LLR computation jointly for the M?D remaining data streams, and reduces the number of hypotheses to consider for the joint LLR computation by performing a search for candidate hypotheses using list sphere detection, Markov chain Monte Carlo, or some other search technique.

Abstract: Methods and apparatus for enhancing estimations of channel response in a wireless communication system are discussed. As an example, a method can comprise: selecting a selected channel from among one or more channels in the communication system; determining, for the selected channel, an initial channel estimate comprising a sequence of frequency-domain samples; determining a phase slope of the initial channel estimate; generating a flat-phase channel estimate by removing the phase slope from the initial channel estimate; and generating an enhanced channel estimate for the selected channel by applying a smoothing function to the flat-phase channel estimate. Other aspects, embodiments, and features are also claimed and described.

Abstract: Disclosed herein are methods and apparatus for enhancing the estimation of channel response in a wireless communication system.

Abstract: A wellhead for subsea use and a method of making same where the wellhead is constituted by a body having a bore (3) therethrough and at least one side bore (9, 11) for provision of fluid communication through the wall of the wellhead (1), and where the wellhead (1) includes a pipe hanger (30) provided with a bore (34) therethrough and a side bore (36) for provision of fluid communication between a tubing string (9?) connected to the pipe hanger (30) and one of the side bores (9) of the wellhead (1), where the wellhead (1) is provided with at least one internal safety valve (42, 44) arranged to be able to shut off fluid communication through the wellhead.

Abstract: Disclosed herein are methods and apparatus for enhancing the estimation of channel response in a wireless communication system.

Abstract: Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs).

Abstract: Techniques for performing detection and decoding at a receiver are described. In one scheme, the receiver obtains R received symbol streams for M data streams transmitted by a transmitter, performs receiver spatial processing on the received symbols to obtain detected symbols, performs log-likelihood ratio (LLR) computation independently for each of D best data streams, and performs LLR computation jointly for the M?D remaining data streams, where M>D?1 and M>1. The D best data streams may be selected based on SNR and/or other criteria. In another scheme, the receiver performs LLR computation independently for each of the D best data streams, performs LLR computation jointly for the M?D remaining data streams, and reduces the number of hypotheses to consider for the joint LLR computation by performing a search for candidate hypotheses using list sphere detection, Markov chain Monte Carlo, or some other search technique.

Abstract: Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs).

Abstract: In a method of manufacturing and laying a plurality of elongate elements into an umbilical comprising a core element, a plurality of conduits of metal and if necessary at least one cable situated outside the core element, which core element is advanced along a feed line and the conduits and the cables are fed onto the outside of the core element and laid in a helix, a first group of single lengths of metal tubes forming the conduits are provided parallel one to another, the single lengths are advanced in the direction of the feed line, a second group of single lengths of metal tubes are provided parallel one to another, the lengths of the second group are advanced in the direction of the feed line and the first ends of the lengths of the second group are welded to the second end of the lengths of the first group, further groups of single lengths of metal tubes are provided and welded to the lengths of the foregoing group respective by, the metal tubes welded together are laid to the outside of the core elemen

Abstract: Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs).

Abstract: In a method of manufacturing and laying a plurality of elongate elements into an umbilical comprising a core element, a plurality of conduits of metal and if necessary at least one cable situated outside the core element, which core element is advanced along a feed line and the conduits and the cables are fed onto the outside of the core element and laid in a helix, a first group of single lengths of metal tubes forming the conduits are provided parallel one to another, the single lengths are advanced in the direction of the feed line, a second group of single lengths of metal tubes are provided parallel one to another, the lengths of the second group are advanced in the direction of the feed line and the first ends of the lengths of the second group are welded to the second end of the lengths of the first group, further groups of single lengths of metal tubes are provided and welded to the lengths of the foregoing group respective by, the metal tubes welded together are laid to the outside of the core elemen

Abstract: Umbilical hose joint for connecting the ends of two hoses (1, 2) to each other in order to establish a continuous hose having a substantially uniform diameter, said joint comprising an inner sleeve extending into the ends of the two hoses (1, 2), each hose being crimped to the sleeve by a hose fitting (6, 7), said inner sleeve (3) being made of a single piece.