Abstract: A technique for encoding a signal used in a digital communication system in which individual traffic channel data rates may be adapted to specific channel conditions. In particular, a forward error correction coding rate is adapted for individual channels while at the same time maintaining a fixed block size independent of the FEC coding rate. This allows the system data rate to adapt to the channel conditions experienced by a specific user. Thus, users experiencing good communication conditions with low multipath distortion may be allocated higher capacity, whereas users with significant multipath distortion may make use of lower rate (higher levels of coding) error codes to maintain high quality. Messages are sent from a transmitter to a receiver to inform the receiver of the coding rate implemented at any given point in time.

Abstract: A technique for a time division multiplex system in which access to shared broadcast communication media is granted on a demand basis. Particular connections are assigned slot times at the transmitter based on demand. However, no specific information regarding the assignment of time slots need be communicated to the receivers. The transmit side employs a forward error correction technique followed by multiplication by a cover sequence unique to each connection. All receivers listen to the broadcast transmission channel all of the time. The receiver assigned to each connection decodes the signals in such a manner that only the receiver with the correct cover sequence assigned to a particular connection will successfully decode the data associated with that connection. Data frames that fail the forward error correction process are discarded, and only those frames which are successfully decoded are passed up to a higher layer.

Abstract: To minimize overhead in the allocation of channels, forward and reverse link time slots are automatically assigned in pairs. In particular, rather than requiring a separate process for allocating reverse link channels for the sending of acknowledgment messages in response to receipt of a forward link packet, a different scenario takes place. At the receiving end, such as for valid reception of data on a forward link channel at a central base station site, a reverse link time slot is automatically allocated in a time slot which depends upon the time slot allocation on the forward link. This assists with the rapid return of acknowledgment messages in a reverse link direction which is the predominant direction for such messages in a wireless system wherein most data traffic is Web page oriented.

Abstract: A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes.

Abstract: In a wireless communication network, a system and method for transferring a wireless session context allows a subscriber access unit to transfer the session context from one base station to another base station depending on a loading factor which indicates the throughput load through each of the base stations. A subscriber access unit which is located in an overlapping wireless coverage area served by both base stations can transfer the session context such that it is served by the base station having the least throughput load. Subscriber access units in overlapping coverage areas will therefore tend to transfer session context to the least burdened base station processor. In this manner, performance is improved because subscriber access units within a wireless coverage area of multiple base station processors are transferred to the base station able to provide the maximum throughput.

Abstract: To minimize overhead in the allocation of channels, forward and reverse link time slots are automatically assigned in pairs. In particular, rather than requiring a separate process for allocating reverse link channels for the sending of acknowledgment messages in response to receipt of a forward link packet, a different scenario takes place. At the receiving end, such as for valid reception of data on a forward link channel at a central base station site, a reverse link time slot is automatically allocated in a time slot which depends upon the time slot allocation on the forward link. This assists with the rapid return of acknowledgment messages in a reverse link direction which is the predominant direction for such messages in a wireless system wherein most data traffic is Web page oriented.

Abstract: A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes.

Abstract: A single, common correlation filter (CF) core is provided in a wireless system using CDMA. A plurality of channels with different data rates are provided in the wireless system. The channels provided in the wireless system include the access channel, the maintenance channel, and the traffic channel in which information (e.g., pilot or data symbols or both) is transmitted at the tier 1, tier 2 and tier 3 rates. The data rate for transmitting the information is programmable by digital signal processor (DSP). A user-unique code, such as a PN code, is applied to the information being transmitted in the channels of the wireless system. The information is QPSK modulated and transmitted in any one of the channels at any data rate. The transmitted information is correlated at the smallest data rate (i.e., the tier 1 rate) in the correlation filter (CF) of the wireless system by time multiplexing delayed versions of the PN code to the correlation filter core.

Abstract: An antenna apparatus that can increase capacity in a cellular communication system. The antenna operates in conjunction with a mobile subscriber unit and provides a plurality of antenna elements, each coupled to a respective signal control component such as a phase shifter. The phase shift for each antenna element is programmed for optimum reception during, for example, an idle mode when a pilot signal is received. The antenna array creates a beam former for signals to be transmitted from the mobile subscriber unit, and a directional receiving array to more optimally detect and receive signals transmitted from the base station. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference. The phase shifters are adjusted in a coarse and a fine mode. In the coarse mode all phase shifters are jointly incremented through several phase shift values until a signal quality metric is optimized.

Abstract: A directive antenna having plural antenna elements is arranged in a parasitic antenna array. Frequency selective components are connected to a first subset of the antenna elements. Weighting structures are connected to a second subset of the antenna elements. The first and second subsets of antenna elements may be connected by a space-fed power distribution system to produce independently steerable beams having spectrally separated signals.

Abstract: A technique for encoding a signal used in a digital communication system in which individual traffic channel data rates may be adapted to specific channel conditions. In particular, a forward error correction coding rate is adapted for individual channels while at the same time maintaining a fixed block size independent of the FEC coding rate. This allows the system data rate to adapt to the channel conditions experienced by a specific user. Thus, users experiencing good communication conditions with low multipath distortion may be allocated higher capacity, whereas users with significant multipath distortion may make use of lower rate (higher levels of coding) error codes to maintain high quality. Messages are sent from a transmitter to a receiver to inform the receiver of the coding rate implemented at any given point in time.

Abstract: An antenna array formed on a deformable dielectric material or substrate includes a center element and plurality of radial elements extending from a center hub. In the operative mode, the radial elements are folded upwardly into an approximately vertical position, with the center element at the center of the hub and the radial elements circumferentially surrounding the center element. In one embodiment the center element serves an active element of the antenna array and the radial elements are controllable in a directive or reflective state to effect a directive beam pattern from the antenna array. When not in use, the antenna elements are deformed into a plane and can therefore be integrated into a housing for compact storage. In a phased array embodiment, the center element is absent and the plurality of radial elements, are controllable to steer the antenna beam.

Abstract: A directional antenna having a number, N, of outlying monopole antenna elements. These monopole elements are formed as a first upper conductive segment on a portion of a dielectric substrate. The array also includes the same number, N, of image elements. The image elements are formed as a second set of lower conductive segments on the same substrate as the upper conductive segments. The image elements, generally having the same length and shape as the monopole elements, are connected to a ground reference potential. To complete the array, an active antenna element is also disposed on the same substrate, adjacent to at least one of the monopole elements. In a preferred arrangement, the passive monopole elements and corresponding image elements are selectively connected to operate to in either a reflective or directive mode, such as via a switchable coupling circuit that selectively changes the impedances connected between them.