Abstract: An acquisition channel (20) includes a UWB sampler block (21) coupled to an analog integration block (22) further coupled to a digital integration block (24) via an analog/digital converter (23). For each range cell the UWB sampler block (21) repeatedly samples the received signal by tuning the sampling instants to the range cells to be acquired. The acquisition channel (20) is further coupled to a processor (26) and a database (25).

Abstract: A method of simplifying the encoding of a predetermined number of bits of data into frames including adding error coding bits so that a ratio of the frame length times the baud rate of the frame times he bit packing ratio of the data divided the total bits of data is always an integer. The method may also convolutionally encode the bits of data so that the same equation is also always an integer.

Abstract: The present invention is a method of simplifying the encoding of a predetermined number of bits of data into frames. The method adds error coding bits so that a ratio of the frame length times the baud rate of the frame times the bit packing ratio of the data divided the total bits of data is always an integer. The method may also convolutionally encode the bits of data so that the same equation is also always an integer.

Abstract: A method for determining changes in internal delays of RF units, the RF units including a plurality of receivers and transmitters. The method includes providing initial direct signals' time of arrivals of the RF units initial internal delays of the RF units. Following this, each transmitter transmitting a direct signal, and the real-time direct signal's time of arrivals of the RF units, are measured. Then, changes in internal delays of the RF units are calculated based on the real-time direct signals' time of arrivals and initial direct signals' time of arrivals. And finally, real-time internal delays of the RF units are calculated based on the changes in internal delays and the initial internal delays of the RF units.

Abstract: Base stations having potentially interfering terminal stations that are geographically located on the same or similar diagonal or Line of Sight (relative to the base station) operate on a first set of time frames (e.g., “even” time frames). Similarly, base stations having potentially interfering terminal stations that are not geographically located on the same or similar diagonals operate on a second set of time frames (e.g., “odd” time frames). By alternating in their use of the even and odd frames, the potential for co-channel interference between terminal stations is minimized. Systems and methods are disclosed which reduce co-channel and adjacent channel interference between terminal stations of different cells as well as adjacent channel interference between terminal stations of adjacent cells. The methods and systems so described can be used during the deployment or expansion of a communication system in a region.

Abstract: A method of assigning downlink time slots to receive units where the units may generate data using different modulation schemes. The method preferably assigns the downlink time slots as a function of the complexity of modulation schemes employed by the units. Further, the method preferably assigns the time slots from the least complex modulation scheme to the most complex scheme. The method may further assign uplink time slots to transmit units where the transmit units may generate data using different modulation schemes. The method preferably assigns the uplink time slots as a function of the complexity of modulation schemes employed by the uplink units. Further, the method preferably assigns the uplink time slots from the least complex modulation scheme to the most complex scheme. In other embodiments, the downlink time slots are assigned as a function of the bit per symbol rate employed by the receive units, preferably from the lowest bit per symbol rate to the highest bit per symbol rate.

Abstract: A method of assigning downlink time slots to receive units where the units may generate data using different modulation schemes. The method preferably assigns the downlink time slots as a function of the complexity of modulation schemes employed by the units. Further, the method preferably assigns the time slots from the least complex modulation scheme to the most complex scheme. The method may further assign uplink time slots to transmit units where the transmit units may generate data using different modulation schemes. The method preferably assigns the uplink time slots as a function of the complexity of modulation schemes employed by the uplink units. Further, the method preferably assigns the uplink time slots from the least complex modulation scheme to the most complex scheme. In other embodiments, the downlink time slots are assigned as a function of the bit per symbol rate employed by the receive units, preferably from the lowest bit per symbol rate to the highest bit per symbol rate.

Abstract: A system that provides a wireless broadband connection between base stations and customer sites is described. The system includes indoor units within the base stations and customer sites and communicate across cables to outdoor units. The indoor units link to routers, switches and other devices and services. The outdoor units transmit and receive wireless data and send it to the indoor units. The indoor units control the timing of detector measurements in the outdoor unit by transmitting a regular, repeating control message at a predetermined time. Once the outdoor unit receives the control message, it samples its detectors and reports measurements back to the indoor unit.

Abstract: A system and method providing a wireless broadband connection between base stations and customer sites. The system includes indoor units, within the base stations and customer sites, that communicate across cables to outdoor units. The indoor units link to routers, switches and other devices and services. The outdoor units transmit and receive wireless data and send it to the indoor units. The indoor units control the functioning of the outdoor units by transmitting digital messages along the interface cables. The outdoor units report various detector values to the indoor units, which allows the indoor units to tune and adjust several functions within the outdoor units. Several embodiments for automatically calibrating the receive path gain in the base stations to compensate for the base station cable between the indoor unit and outdoor unit are described. In addition, an improved transmit power control technique which is not affected by modulation type, is also described.

Abstract: The system and method optimizes a SNR calculation for a signal received during a downlink burst even in the absence of a node's preferred modulation. This system and method are used in communication systems that include a multi-modulation modem. An adaptation factor is selected whereby its use during portions of the downlink burst, which were not modulated using the preferred modulation, provides the SNR. The selected adaptation factor is used by an equalizer to perform channel inversion to the signal. The system and method can be used in, for example, an FDD or TDD communication system. Such communication systems can be, for example, symmetric, asymmetric, and/or adaptive in their operation.

Abstract: A system and method for enhancing the performance of an equalizer in a modem. Multiple techniques are disclosed which improve the modem performance. A first technique uses stored parameters for each burst from each remote site to demodulate a received data stream. A second technique compensates for the gain droop caused by storing parameters across each burst. A third technique minimizes errors caused by adapting the equalizer coefficients for each data burst by analyzing the SN ratio and error rate of the received burst. A fourth technique improves the convergence of the equalizer by using a two-part preamble, whereby both parts are transmitted using different modulation techniques. A fifth technique is provided which performs a soft reset of the modem without performing a complete reset of the modem. A sixth technique determines a modem adaptation factor based on the expected modulation type of an incoming burst transmission.

Abstract: On embodiment of the system and method provides asymmetric adaptive modulation which allows uplink and downlink subframes of data to be transmitted between a base station and a CPE with different modulation schemes, thus increasing the efficiency of downlink transmissions while maintaining the stability of uplink transmissions. In systems with multiple CPEs, each CPE and base station pair can independently select their uplink and downlink modulation techniques. The system and method are also adaptive in that they adjust the modulation schemes based on, for example, signal to noise ratio measurements or bit error rate measurements.

Abstract: On embodiment of the system and method provides asymmetric adaptive modulation which allows uplink and downlink subframes of data to be transmitted between a base station and a CPE with different modulation schemes, thus increasing the efficiency of downlink transmissions while maintaining the stability of uplink transmissions. In systems with multiple CPEs, each CPE and base station pair can independently select their uplink and downlink modulation techniques. The system and method are also adaptive in that they adjust the modulation schemes based on, for example, signal to noise ratio measurements or bit error rate measurements.

Abstract: A system and method for enhancing the performance of an equalizer in a modem. Multiple techniques are disclosed which improve the modem performance. A first technique uses stored parameters for each burst from each remote site to demodulate a received data stream. A second technique compensates for the gain droop caused by storing parameters across each burst. A third technique minimizes errors caused by adapting the equalizer coefficients for each data burst by analyzing the SN ratio and error rate of the received burst. A fourth technique improves the convergence of the equalizer by using a two-part preamble, whereby both parts are transmitted using different modulation techniques. A fifth technique is provided which performs a soft reset of the modem without performing a complete reset of the modem. A sixth technique determines a modem adaptation factor based on the expected modulation type of an incoming burst transmission.

Abstract: A system and method providing a wireless broadband connection between base stations and customer sites. The system includes indoor units, within the base stations and customer sites, that communicate across cables to outdoor units. The indoor units link to routers, switches and other devices and services. The outdoor units transmit and receive wireless data and send it to the indoor units. The indoor units control the functioning of the outdoor units by transmitting digital messages along the interface cables. The outdoor units report various detector values to the indoor units, which allows the indoor units to tune and adjust several functions within the outdoor units. Several embodiments for automatically calibrating the receive path gain in the base stations to compensate for the base station cable between the indoor unit and outdoor unit are described. In addition, an improved transmit power control technique which is not affected by modulation type, is also described.

Abstract: Base stations having potentially interfering terminal stations that are geographically located on the same or similar diagonal or Line of Sight (relative to the base station) operate on a first set of time frames (e.g., “even” time frames). Similarly, base stations having potentially interfering terminal stations that are not geographically located on the same or similar diagonals operate on a second set of time frames (e.g., “odd” time frames). By alternating in their use of the even and odd frames, the potential for co-channel interference between terminal stations is minimized. Systems and methods are disclosed which reduce co-channel and adjacent channel interference between terminal stations of different cells as well as adjacent channel interference between terminal stations of adjacent cells. The methods and systems so described can be used during the deployment or expansion of a communication system in a region.