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: 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: There is provided a scheme for centering data prior to detection. It comprises: determining carrier frequency error, and pre-adjusting the data detection process to compensate for that error throughout the ensuing data detection. This scheme for reliable multi-level data detection further comprises: upon detection of carrier presence, determining carrier frequency error, gating a voltage associated with the frequency error to the differential amplification process to establish common mode rejection and compensating for that error throughout the ensuing multi-level data detection, and then analog-to-digital conversion of the differentially amplified multi-level data. A scheme for computationally centering the subsequent data detected to compensate for the error is also provided.

Abstract: A system for facilitating link continuity and prompt supervisory control in a communication system with discontinuous transmissions comprising varying the carrier power in a first communication unit and varying frequency deviation of a modulating signal to provide a continuous signal detectable by a second communication unit, where continuous monitoring at the second communication unit allows for rapid detection and reaction to received supervisory control signals through the use of continually comparing the received supervisory signal to an expected signal and qualifier signal to enhance the reaction time of the second communication unit.

Abstract: There is provided a mechanism for soft trellis decoding. It comprises: generating decisions that rely upon other decision making and associating with it information indicative of the confidence held in those decisions and generated from the relative merit of any given decision. It further comprises: generating Maximum Likelihood Sequence Estimation equalization decisions and multiplying a signed value of the generated decision by the absolute values of the difference between alternative criterion utilized to arrive at any given decision, whereby the relative merit comprises a measure of signal quality at the time that given decision is made.

Abstract: In a network of interconnected wireless networks and wired telephone networks, there is provided a mechanism for sustained association of users with communications paths. It comprises: upon an attempted use of an unassociated telephone, identifying oneself to the network (via the wireless network) and activating one's telephone line by keying one's own telephone number through the telephone keypad, locating his telephone line by monitoring unassociated lines for activity, and the one so identified receiving a sustaining association (for more than a few communications) with the telephone line so located.

Abstract: In a receiver employing complex correlation, there is provided a mechanism for carrier frequency offset equalization. There exists a linear phase progression in the correlation process that is indicative of frequency offset. One method involves curve fitting the phase progression in order to warp the sync word against which subsequent correlation is performed rather than controlling the reference frequency of the receiver. The other successively approximates the phase progression by pre- and re-warping the synchronization reference word within the correlation process itself rather than controlling the reference frequency of the receiver.

Abstract: In a communication system having a time base for system synchronization, there is provided a method and apparatus for controlling the sensitivity of a receiver comprising the steps of (a) receiving a signal that was predeterminally transmitted by another relative to the time base (wherein signal reception is confirmed when the amplitude of the received signal exceeds a pre-established threshold), (b) determining signal transit time from the time difference between the instant of signal reception relative to the time base and the instant of signal transmission relative to the time base, (c) controlling the sensitivity of the receiver as a function of the transit time by: (1) increasing the gain of the receiver from a minimum sensitivity at the predetermined transmission instant to a maximum sensitivity at maximum range (maximum expected transit time) and (2) nominally maintaining the receiver's gain at the level prevailing at the instant the signal is received.

Abstract: A method comprising distributing channel coding on either side of a limited capacity communication path by partially channel coding a signal at a first processing point and communicating the partially coded signal over the communication path to a second processing point. The partially coded signal comprises at least some but not all of the necessary coded bits. The channel coding algorithm is completed at the second processing point using the communicated partially coded signal thereby increasing throughput over the limited capacity path while minimizing added delays.

Abstract: A non-hermetic, three-dimensional, microwave semiconductor device carrier with integral waveguide couplers is disclosed. A molded plastic substrate having a suitable dielectric constant and varying thicknesses comprises plated conductors and locations for receiving GaAs MMIC's. MMIC's are mounted to a metal backplate and die bonded to the plated conductors. The waveguide couplers are integrally molded as part of the carrier substrate, and comprise plated through cylindrical members. Signals from a waveguide cavity are coupled to the MMIC's by inserting the waveguide couplers into a waveguide port. The carrier and integral waveguide coupler together with a plated molded cover forms a non-hermetic package providing pseudo-shielding cavities about the resident multiple semiconductor GaAs die. Transmission line impedance control is enhanced varying the substrate thickness on a per conductor basis. Frequency of operation exceeds 12 gigahertz.

Abstract: In a radio frequency communication system employing channelization, such as a cellular TDMA system, and having a plurality of reuse channel levels, such as multiple frequency reuse patterns, each level having at least one associated reuse channel, a method and device comprising: determining relative interference for a reuse channel of a first reuse level in relation to relative interference for a reuse channel of at least a second reuse level resulting in a reuse level gradient and assigning the subscriber unit to at least one reuse level in response to the reuse level gradient.

Abstract: There is provided a scheme for bit error rate detection. It comprises: detecting the bit value present in a received multi-level signal, more narrowly detecting the bit value present in that received multi-level signal, comparing the results of narrow detection with the results detected otherwise to identify errors in detection, and accumulating detected symbol errors over unit time. Bit error rate detection can be used for antenna selection--selecting one of a plurality of diversity antennas when the error rate exceeds a certain error threshold.

Abstract: A method and appartus for diversity reception in a communication system wherein at least a dual branch receiver is provided with a stored replica of expected reference information that is correlated with the received time-dispersed signals to obtain an estimate of the transmission channel's impulse response as seen by each branch, and determine, among other things, phase error between the branch local oscillators and the time-dispersed signals. Matched filters are constructed which then coherently align the time-dispersed signals from each branch with that branch's local oscillator, also constituting the first part of the equalization. The diversity processing stage may perform bit by bit selection on the re-aligned signals, maximal ratio combining of the re-aligned signals, or equal gain combining of the re-aligned signals, following each by a sequence estimation which uses similarly selected or combined channel distortion compensation parameters to complete the equalization process on the new signal.

Abstract: An interference detecting circuit is used in a cellular radiotelephone communication system which employs angular modulated frequencies in order to determine when to change the communication process so as to maintain the integrity of the communication path. For example, when the circuit detects an excessive amount of multipath or co-channel interference on a channel serving an active call, the system may decrease the effective data bit rate. The circuit includes a logarithmic envelope detector for receiving a channel's angular modulated signal and for providing a log envelope output signal, a high pass filter for removing a particular range of undesired frequencies from the log envelope output signal, and a level detector for indicating the level of filtered output signal. The output of the level detector represents the amount of interference on the angular modulated frequency signal. A microcomputer analyzes the amount of interference to determine when such communication process changes are desired.

Abstract: A cellular system employs a subaudible signalling control protocol. The protocol includes transmitting supervisory related signals between the radiotelephone and one of the cell sites at a first subaudible digital bit rate, and transmitting data messages between the radiotelephone and said one of the cell sites at a second subaudible digital bit rate. Additionally, the system employs specific protocols involving alert, hand-off and call disconnect which accommodate the subaudible signalling, yet provide significant integrity and reliability advantages over previously known protocols.

Abstract: A telephone system employs a novel message system for calling parties. The switch controller includes selectable and programmable announcement machines, while the telephone devices include indicators which allow call transferees the ability to determine the reason the call was transferred, e.g., the called telephone was busy, did not answer or the called telephone party is in conference. When desired, a telephone party is capable of programming the switch controller to reply to any particular incoming phone calls with one of a number of customized or preselected messages.