Abstract: A telecommunications terminal includes a memory and a processor programmed to execute instructions stored in the memory. The instructions include determining an estimate of a link attenuation of a first communication link while receiving a channel and applying the estimate of the link attenuation to a second communication link after transitioning to the second communication link.

Abstract: A telecommunications terminal includes a memory and a processor programmed to execute instructions stored in the memory. The instructions include determining an estimate of a link attenuation of a first communication link while receiving a channel and applying the estimate of the link attenuation to a second communication link after transitioning to the second communication link.

Abstract: A multisubscriber unit is disclosed for use of in a digital cellular communication system to communicate with a base transceiver station and eventually to switched telephone network. The multisubscriber unit connects to a plurality of individual subscriber telephones. It includes a plurality of upconverters, modulators, downconverters, demodulators speech compressors, speech decompressors, and voice activity detectors that are assigned to a subscriber telephone upon detection of an off hook signal from the telephone. Preferably, upon the detection of data to be transmitted, to channel allocation is requested from a pool of time division multiple access channels in a digital speech interpolation pool.

Abstract: A digital cellular communication system in which fixed subscribers and mobile subscribers share base transceiver stations, base station controllers and mobile switching centers to communicate with the switched telephone network. Mobile subscribers communicate using any cellular radio protocol, while the fixed subscribers communicate via a multi-subscriber unit (MSU) using the inventive air interface. The MSU system uses digital speech interpolation to transmit speech spurts between subscribers and the switched telephone network. Preferably, time division multiple access channels in a digital speech interpolation pool are allocated and deallocated on a speech spurt basis.

Abstract: The present invention provides for carrier offset tracking which is particularly well suited for use in a receiver for digital cellular mobile telephones. The tracking includes storing samples received in time slots, generating estimates of the transmission channel impulse response, recording two samples of each tap of each channel impulse response estimate, generating frequency offset estimates from the phase difference in each time slot between the samples, combining this plurality of frequency offset estimates to generate a precise frequency offset estimate, and adjusting a controllable frequency source to compensate for the precise frequency offset estimate. Time-reversed operation further enhances performance and permits implementation with reasonable complexity for a standards compliant mobile receiver.

Abstract: The present invention provides for sample timing adjustment using channel impulse response which is particularly well adapted for use in a receiver for digital cellular mobile telephones. The sample timing adjustment includes storing samples in time slots, generating estimates of the transmission channel impulse response, and using a subset of the samples received during the time slot, and generating error measurements of the degree to which the estimated channel impulse responses match the actual channel impulse responses. The different measures use simultaneously recorded samples having different time offsets. At least one sample used for each measure is advanced in time and one sample used for each measure is retarded in time relative to the samples used for generating the first measure. Then, a sample time setting that minimizes the error measurement is determined and the sampling is adjusted to reflect the newly determined sample time setting.

Abstract: A mobile telephone system multiplexes plural voice traffic channels on a single carrier using a TDMA protocol. The capacity of the mobile telephone system is increased by assigning voice traffic capacity, not on a conversation basis, but on an information burst basis. In order to avoid compromising the voice transmission capacity, control signals (for the allocation and deallocation of both forward and reverse traffic channels) are sent using multiple diversity, i.e. both time and frequency. In addition, to increase the number of available control channels, a control channel comprises a sub-divided portion of an otherwise equivalent voice traffic slot. For reverse allocation requests, which are transmitted over a contention access channel, power diversity is used in addition to time and frequency diversity.

Abstract: The present invention provides for a receiver that employs integrated symbol timing adjustment and carrier tracking algorithms based on channel impulse response estimates. It uses variable coefficient least mean square tracking during estimation of the transmission channel's impulse response. Maximum likelihood sequence estimation equalization can also be integrated into the system using a non-real time operation that permits and exploits "time-reversed" equalization to significantly enhance bit-error rate performance and permits implementation of all the functions in a reasonably simple receiver.

Abstract: A mobile telephone system multiplexes plural voice traffic channels on a single carrier using a TDMA protocol. The capacity of the mobile telephone system is increased by assigning voice traffic capacity, not on a conversation basis, but on a speech spurt basis. Accordingly, delays of undetermined duration may occur between subsequent information bursts which correspond to the transmission of speech spurts. An adjustment request regarding the power with which the information bursts are transmitted from a transmitting station to a receiving station is generated by detecting an information burst transmission at the receiving station, measuring the time which elapses following the transmission, and comparing the elapsed time with a predetermined threshold value. If the elapsed time exceeds the threshold, a further transmission is requested from the transmitting station notwithstanding the availability of any information to transmit.

Abstract: A receiver for use in digital cellular communication systems determines the type of data transmitted without having to decode the data. Digital cellular communication systems typically use convolutional forward error correction (FEC) coding to allow for error detection and correction at the receiver. The type of encoding is different depending on whether voice data or control data is transmitted. In general, FEC coding is a redundant coding of the encoded data so that for a given encoding algorithm with FEC coding, there will be a limited number of valid code sequences less than the total possible number of code sequences for a transmission of the same number of bits. This characteristic is used to identify the type of encoding without decoding the received information. Consequently, decoding requirements are reduced to those corresponding to the active transmitting encoder, resulting in receiver complexity reduction.

Abstract: The present invention provides for an equalization method that forms the nucleus of a receiver for digital cellular mobile telephones. A number of distinct aspects of the design are considered novel, including non-real time operation that permits and exploits "time-reversed" equalization to significantly enhance bit error rate performance. The present invention employs the use of a maximum likelihood sequence estimation process. It uses variable coefficient least mean square tracking during estimation of the transmission channel's impulse response. It also employs the use of integrated symbol timing adjustment and carrier tracking algorithms. Time-reversed operation further enhances performance and permits implementation with reasonable complexity of a standards compliant mobile receiver.