Terrace Communications Corporation

Maxtor Corporation

Nathan Hays

Stan Shepherd

David Asson

A satellite communications system can use a spread-spectrum waveform and format, a synchronization scheme, and/or a power management algorithm. This approach can provide benefits such as allowing every terminal to communicate with every other terminal, link margin permitting. This gives the network a mesh topology although it can be configured in a star topology for highly asymmetric applications. A further understanding of the nature and the advantages of particular embodiments disclosed herein may be realized by reference of the remaining portions of the specification and the attached drawings.

Signal coding for improved spectral quality

A receiver includes a plurality of de-spreading correlators that are programmed to only correlate a specific portion of the full spreading code according to an interleave factor. Each correlator may be associated with a different symbol. The received signal may be received at all correlators and is multiplied by a code generated by a code generator according to the symbol associated with the correlator. While each correlator may be despreading the received signal at all times, an enable signal is used to determine when information for an associated cell should be accumulated for each correlator.

Orthogonal symbol interleave for spreading signals

Symbol interleave for wireless communications

Systems, apparatuses, and methods for providing timing estimates of received signals are disclosed. In one embodiment, sub-chip timing in spread spectrum signals can be achieved without requiring oversampling in the receiver. A transmitter can adjust the timing of certain transmitted symbols by a fraction of a chip time from an expected time, and send the mistimed symbols to a receiver. The output of the receiver's de-spreading correlator can show different magnitudes for wedge symbols with different timing errors. By setting some symbols early and some late, and by taking the difference between their magnitudes, a transfer function between the result and a timing error can be determined.

Measurement of baseband timing in a spread spectrum communications system

Particular embodiments provide techniques for controlling power in a channel. The power being consumed in a channel may not always be fully used. For example, bursty or Aloha traffic may limit the power being used to transmit data in a channel. Thus, particular embodiments allow transceivers to increase the power used to transmit data in a channel. For example, many transceivers may be allowed to send data in a channel. If all transceivers were transmitting at once at an increased power level, the aggregate power level may be exceeded for the channel. All the transceivers may be allotted a fixed percentage of the aggregate power so as to guarantee not exceeding the power limit. However, not all transceivers may be using their allotted power at the same time. Thus, when the allotted aggregate power in the channel is not fully utilized, a transceiver may increase its traffic beyond its normal portion. For example, the transceiver may use a power-demanding high order modulation scheme to send data.

Techniques to control power by controlling aggregate traffic in a channel

A disk drive includes a head and a disk, spiral patterns are located on the disk, and the disk drive self-writes servo patterns on the disk using the spiral patterns as a reference for servoing the head. In an embodiment, the disk drive uses preliminary servo patterns to determine repeatable runout of the spiral patterns. In another embodiment, the disk drive reads each spiral pattern with multiple timing windows.

Growing community of inventors

San Francisco, CA, United States of America

Nathan Hays