Abstract: In a communications network having time-dispersed signals, there is provided a mechanism for soft decision decoding. It comprises: radio reception of a time-dispersed signal, at least partly equalizing those time-dispersal effects, recovering information contained in the signal, multiplying with that recovered information the absolute value of that at-least-partly-equalized signal (scaled by a number derived from channel conditions over a time during which at least part of the information to be recovered is distributed), and error-correcting the multiplied information by a Viterbi algorithm channel decoding scheme of error correction. Accordingly, soft decision information is generated from within the equalization process itself.

Abstract: In a cellular radiotelephone network, there is provided a mechanism for dynamic frequency reuse. It comprises: allocating according to one reuse pattern during one time interval at least one of a plurality of hopped carriers and allocating according to another reuse pattern during another, substantially non-overlapping time interval that hopped carrier, all in substantially non-interfering time synchronism with any proximal reuse of that carrier. The attendant advantage is the realization of a dynamically allocatable frequency reuse, using shared carriers and frequency hopping to provide the desired C/I performance.

Abstract: A method for compensating for capacity overload in a communication system by first determining the received signal power level at a base site is described. The power level is compared with a threshold power level. If the received power level is greater than the threshold, the signal-to-noise ratio for the system is reduced. With the acceptable signal-to-noise ratio reduced, the subscriber power will be reduced. The received signal power level at the base site will then return to the threshold level. Alternatively, a signal-to-noise ratio of a pilot signal can be determined at the base. The signal-to-noise ratio is compared to a threshold signal-to-noise ratio. If the signal-to-noise ratio of the pilot is less than the threshold, the threshold level is reduced. With the acceptable signal-to-noise ratio reduced, the subscribers are directed to reduce their power.

Abstract: A central-site (100) has located within it a synchronization system for purposes of backing-up a GPS external synchronization system. The central-site (100) is coupled to a plurality of base-sites (102, 103) which are required to be synchronized to one another. When the GPS signal is lost, the synchronization system within the central-site (100) allows the plurality of base-sites (102, 103) to maintain synchronization to one another. In this manner, the necessity for a synchronization system within each of the plurality of base-sites (102,103) is eliminated.

Abstract: A CM (105) receives requests for data transfer from a series of UMs (101-103) and from an EM (104). The requests contain the UM (101-103) or EM (104) address and the size of the data packet to be transferred. The CM (105) processes the requests on a FIFO basis, stores the requests in a queue and assigns either a small data channel or a large data channel, depending on the packet size to be transferred, and also the corresponding number of required timeslots. The CM (105) picks the first request off the queue and sends a grant to the particular UM (101-103) or EM (104) which receive the grant and immediately access either the assigned small or large data channels in the required number of timeslots.

Abstract: An apparatus scales binary samples representing a predetermined waveform (109) to achieve every possible transition in a multi-level transmission system. The predetermined waveform (109) is partitioned into M symbol intervals, each symbol interval having a corresponding waveform represented by a series of binary samples V stored in M separate ROM devices (311-316). Depending on the required amplitude and polarity of the transition, logic blocks (351-356) control scaling multipliers (321-326) and polarity multipliers (331-336) to perform the required scaling and inverting of the binary samples retrieved from ROM (311-316). The scaled and inverted samples are added together by an adder (345) and sent to a D/A converter (350) where the desired scaled and inverted waveform is converted/generated from the scaled and inverted binary samples.

Abstract: A noise signal is obtained from a data processor output, such as a data line, an address line, or a control line, and used to control the frequency modulation of an oscillator. The modulated output is used to clock the data processor.

Abstract: A password scheme wherein a node is provided a configuration message at start-up which configures a shell of the node directing a search order of network password files. The node, group, and network password files are then transparently searched in the order specified by the configuration message.

Abstract: A first bit of the communication signal is encrypted and forwarded to a CRC where it is processed in parallel with the encryption of the second bit. The first bit is then passed to the scrambler and the second bit is passed to the CRC where they are processed in parallel with a third bit which is encrypted. This process continues until the last bit is scrambled.

Abstract: A communication system having a site employing a plurality of communication channels. Each channel is assigned a desired received signal strength threshold. A channel is assigned to a subscriber unit based upon the strength of the signal received at the site and the power control range of the subscriber unit. The selection of a channel may be performed either by the site or the subscriber unit. In an FDMA environment, each separate frequency division channel may be assigned different received signal strength thresholds. In a non-overlapping time interval (TDMA) environment, each separate time division channel may be assigned different received signal strength thresholds. In another embodiment, a combination of FDMA and TDMA environments can be used.

Abstract: A cellular radiotelephone system transfers a call from a source base-site (200) to one target base-site (205,210). A source base-site (200) in the first RF coverage area (100) measures the signal strength (RSSI.sub.S) of a mobile (225), provides a forecasted signal strength (RSSI.sub.F) representing a would-be power increase of the mobile (225) and sets up two time windows. The source base-site (200) sends the measured and forecasted signal strengths to candidate target base-sites (205,210) found by the mobile (225) which measure the mobile (225) signal strength (RSSI.sub.T) and compare it once to RSSI.sub.S plus a hysteresis value. If RSSI.sub.T is greater than RSSI.sub.S, the call is transferred to the best responding cell. If RSSI.sub.T is below RSSI.sub.S, RSSI.sub.T is compared to RSSI.sub.F. During this time, the mobile 225 will increase power at the end of the first time window. If RSSI.sub.T is ever greater than RSSI.sub.

Abstract: In a TDMA cellular system, there is provided a mechanism for splitting the allocation of time slots within a TDM frame between adjacent coverage areas. There is provided a method of and apparatus for time-allocation of TDMA channels. It comprises: periodically allocating some portion of a carrier of radio traffic to one coverage area during one time interval and periodially allocating some other portion of that same carrier to another coverage area during a substantially non-overlapping time interval, all in time synchronism with any proximal reuse of that carrier. The distribution of channels in adjacent coverage areas thereby approaches parity and the minimum channel capacity per coverage area is enchanced.

Abstract: A programmable logic device having four AND gate means defined therein is used to combine first and second inputs as well as multiplexing and latch signals. These signals are ANDed together (first input and multiplexing signals; inverted multiplexing signal and latch signal and second input; inverted multiplexing signal, second input signal and device output signal; and inverted latch signal and device output signal) to provide four output signals which are ORed together to produce the device output signal.

Abstract: A receiver module 140 controls the amplitude of a random burst signal 200 in a TDMA system. A random burst signal 200 presence detector 330 detects when the random burst signal 200 has arrived during a timeslot reserved for the random access burst 200. After detection, a control processor monitors the signal strength or amplitude of the random access burst 200 for a predetermined time period, determines the amount of AGC attenuation required, and inserts the required AGC attenuation to control the amplitude of the random access burst 200 for the duration of the timeslot.

Abstract: An apparatus automatically corrects for DC offset in a multi-level packet-switched receiver. A reference carrier frequency is used during the receiver's idle mode to establish a DC offset exiting a discriminator (302). The DC offset is amplified by a video amplifier (315) and fed into an error amplifier (320) which generates the negative of the DC offset. The DC offset and the negative of the DC offset are input into a summing network (330) resulting in a zero DC offset exiting the video amplifier (315).

Abstract: A receiver 200 automatically compensates for intermodulation of an input signal. The receiver 200 is preceded by a receiver front-end 105 which is coupled to antennas 100-102 receiving the signal. The gain of the antenna path/frequency is calibrated and stored for all combinations of antenna path/frequency. When a signal is received, the receiver 200 determines the correct stored gain factor representing the antenna receiving the signal and the frequency of the signal. The gain factor is compared against a predetermined threshold, and if the gain factor is greater than the threshold, an attenuator 400 placed at the front of the receiver 200 is inserted to optimize signal intermodulation. If the gain factor less than the threshold, the attenuator 400 is bypassed to optimize the sensitivity of the receiver 200.

Abstract: A requesting manager sends a message to its local configuration processor requesting notice of status changes in a general or particular, resource or node. The configuration manager establishes a record in its status monitoring file containing the information from the requesting process' message. The configuration manager receives messages: from remote configuration managers or local resource managers regarding resource status changes; and from its local network interface module regarding node changes. The configuration manager then compares these status change notifications with the records in its status monitoring file. If there is a match, the configuration manager sends a message to the requesting process reporting the status change. The status changes that are reported may be limited by the requesting process by specifying a particular status change, a particular resource, or other option.

Abstract: A distributed data processing system is provided comprising a plurality of processes which communicate with one another using messages. When a process is created or terminated anywhere in the system a notification message may be requested. Such requests may be made regarding different organizational levels of the system, for example the entire system, one node, or a group of related processes.

Abstract: An analog signal is input to a converter where a feedback signal is subtracted to form an analog error signal. The analog error signal is then processed through a first quantizer to provide a course output bit. The difference between the input and output of the first quantizer is then processed through a second quantizer to provide a trim output bit. The two bits are combined and returned as the feedback signal and are provided to a decimation filter which will provide the digital output representation of the analog input.