Abstract: A method for enabling synchronization of a communications terminal in a wireless communication system, and a corresponding acquisition system of the communications terminal, wherein the method consists of the steps of: receiving a burst at a receiver of the communications terminal, the burst containing a composite waveform including two or more component waveforms, wherein each of the two or more waveforms has a known frequency variation throughout the burst; detecting the presence of the composite waveform; and estimating a frequency offset and a timing offset of the composite waveform as received into the receiver, whereby synchronization is achieved.

Abstract: A method is disclosed to operate a spread spectrum receiver with an active set of base stations. The method includes monitoring a current serving base station of the active set with a Set Searcher and simultaneously monitoring individual ones of remaining base stations of the active set with a C/I (carrier-to-interference ratio) Searcher. One of the remaining base stations is designated as a Candidate base station for potentially replacing the current serving base station and is monitored continuously by a first set of fingers of the C/I Searcher. The other remaining ones of the base stations of the active set are monitored in a time multiplexed manner by a second set of fingers of the C/I Searcher.

Abstract: A method is disclosed to operate a spread spectrum receiver with an active set of base stations. The method includes monitoring a current serving base station of the active set with a Set Searcher and simultaneously monitoring individual ones of remaining base stations of the active set with a C/I (carrier-to-interference ratio) Searcher. One of the remaining base stations is designated as a Candidate base station for potentially replacing the current serving base station and is monitored continuously by a first set of fingers of the C/I Searcher. The other remaining ones of the base stations of the active set are monitored in a time multiplexed manner by a second set of fingers of the C/I Searcher.

Abstract: A waveform to be transmitted as a burst within a channel that is used for the synchronization of unsynchronized wireless communications terminals in a wireless communications system, and a method of synchronization involving the waveform, that consists of a composite waveform. The composite waveform comprises two or more component waveforms, wherein each of the two or more component waveforms has a known frequency variation throughout the burst. The composite waveform has a composite bandwidth on an order of an available channel bandwidth and each of said two or more component waveforms have a component bandwidth on the order of the available channel bandwidth. Furthermore, a range of values for the differences between the instantaneous frequencies of two of said two or more component waveforms is on an order of twice of said available channel bandwidth.

Abstract: A system and method of blind channel estimation to receive a signal burst over a communications channel; divide the signal burst into a prescribed number of groups of symbols; hypothesize all possible transmitted data sequences or each group; generate a corresponding channel estimate for each possible data sequence; determine an error measurement for each corresponding channel estimate; select a number of the corresponding channel estimates for each group from amongst the corresponding channel estimates, the number of the corresponding channel estimates being selected for having smaller error measurements than remaining corresponding channel estimates not selected; identifying a best channel estimate for each group from amongst the number of the corresponding channel estimates having been selected for each group; and reviewing the best channel estimate having been identified for each group and reidentifying best channel estimates for some of the groups so as to increase smoothness of a curve in two-dimensiona

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: 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: 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.