Abstract: A method and apparatus for enhancing coding efficiency by reducing illegal or other undesirable packet generation while encoding a signal. The probability of generating illegal or other undesirable packets while encoding a signal is reduced by first analyzing a history of the frequency of codebook values selected while quantizing speech parameters. Codebook entries are then reordered so that the index/indices that create illegal or other undesirable packets contain the least frequently used entry/entries. Reordering multiple codebooks for various parameters further reduces the probability that an illegal or other undesirable packet will be created during signal encoding. The method and apparatus may be applied to reduce the probability of generating illegal null traffic channel data packets while encoding eighth rate speech.

Abstract: A method and system that combines voice recognition engines and resolves differences between the results of individual voice recognition engines using a mapping function. Speaker independent voice recognition engines and speaker-dependent voice recognition engines are combined. Hidden Markov Model (HMM) engines and Dynamic Time Warping (DTW) engines are combined.

Abstract: Methods and apparatus are presented to select optimal transmission formats for transmissions to a single user or simultaneous transmissions to multiple users. Priority information and channel state information associated with each user are used to determine the optimal transmit formats. In particular, said formation is used to maximize a given revenue function that enhances system throughput while maintaining fairness among users. Once transmit formats are determined, any unallocated system resources, such as unused Walsh codes or transmission power, can be evenly or proportionately distributed among the users.

Abstract: A method and apparatus for generating an autonomous Pilot Strength Measurement Message (PSMM) by a mobile station traveling in a multi-carrier wireless communication system. In a multi-carrier system, the mobile station receives the pilot channel of a base station on multiple carrier frequencies simultaneously. Fading may vary from carrier frequency to carrier frequency. New pilot strength definitions are used by the mobile station in a set of rules transmitted by the base station. The set of rules determines autonomous generation and transmission of PSMMs by the mobile station upon detection of pilots.

Abstract: Methods and apparatus are presented for implementing an improved Control-Hold Mode that reduces the load of the reverse link and reduces the battery consumption of remote stations. While a remote station is in the improved Control-Hold Mode, the circuitry that monitors the forward packet data channels and the associated control channels are turned off. Since the forward packet data channels and their associated control channels are not monitored, the operations of the reverse channels can be gated off to predetermined duty cycles, or set on intermittent transmission modes, or shut down completely. Transitions from the Control-Hold Mode to the Active Mode can be initiated by the remote station or by a base station. When a transition is initiated by a remote station, the remote station transmits a signaling message to a serving base station and then starts operating the feedback channels before actually receiving forward link signals.

Abstract: A method for coherent estimation of the traffic-to-pilot energy ratio is presented. A received preamble is decoded, and then re-encoded. The received preamble is then multiplied by the re-encoded preamble. The results are summed, squared, and then divided by a pilot energy value. In another method, a message carrying energy information can be inserted between a subpacket preamble and a subpacket.

Abstract: A novel and improved method and apparatus for providing an interface to a digital wireless telephone system compatible with standard analog wire line fax machines is described. To process a fax, a source interface waits until an interface to a destination fax machine has been established before establishing an interface to a source fax machine. The source fax transmission rate must be less than or equal to the destination fax transmission rate and the data rate of the digital channel. To establish the source fax interface at the proper rate, the source interface first selects and initial data rate from a set of standard fax transmission rates. The source interface sends unacceptable rate (failure to train) messages to the source fax machine until the source fax transmission rate is less than or equal to the data channel rate and the destination fax transmission rate.

Abstract: Techniques for puncturing symbols in a communications system. S symbols are received for a frame having a capacity of N symbols, with S being greater than N. P symbols need to be punctured so that remaining symbols fit into the frame. A number of puncture distances, D1 through DN, are computed based on S and P. A particular number of symbol punctures is determined for each computed puncture distance. P1 through PN symbol punctures are then performed at the distances of D1 through DN, respectively. For a more even distribution of the symbol punctures, each of the distances D1 through DN can be selected to be greater than or equal to a minimum puncture distance Dmin defined as Dmin=└S/P┘, where └ ┘ denotes a floor operator. The symbol punctures at each computed distance can be performed together or distributed with symbol punctures at other distances.

Abstract: A method and system that improves voice recognition by improving storage of voice recognition (VR) templates. The improved storage means that more VR models can be stored in memory. The more VR models that are stored in memory, the more robust the VR system and therefore the more accurate the VR system. Lossy compression techniques are used to compress VR models. In one embodiment, A-law compression and A-law expansion are used to compress and expand VR models. In another embodiment, Mu-law compression and Mu-law expansion are used to compress and expand VR models. VR models are compressed during a training process and they are expanded during voice recognition.

Abstract: Method and apparatus for subsampling phase spectrum information by analyzing and reconstructing a prototype of a frame. The prototype is analyzed by correlating phase parameters generated from the prototype with phase parameters generated from a reference prototype in multiple frequency bands. The prototype is reconstructed using linear phase shift values by producing a set of phase parameters of the reference prototype, generating a set of linear phase shift values associated with the prototype, and composing a phase vector from the set of phase parameters and the set of linear phase shift values across multiple frequency bands. The prototype is reconstructed using circular rotation values by producing a set of circular rotation values associated with the prototype, generating a set of bandpass waveforms associated with the phase parameters of the reference prototype in multiple frequency bands, and modifying the set of bandpass waveforms based upon the circular rotation values.

Abstract: A closed-loop, multimode, mixed-domain linear prediction (MDLP) speech coder includes a high-rate, time-domain coding mode, a low-rate, frequency-domain coding mode, and a closed-loop mode-selection mechanism for selecting a coding mode for the coder based upon the speech content of frames input to the coder. Transition speech (i.e., from unvoiced speech to voiced speech, or vice versa) frames are encoded with the high-rate, time-domain coding mode, which may be a CELP coding mode. Voiced speech frames are encoded with the low-rate, frequency-domain coding mode, which may be a harmonic coding mode. Phase parameters are not encoded by the frequency-domain coding mode, and are instead modeled in accordance with, e.g., a quadratic phase model. For each speech frame encoded with the frequency-domain coding mode, the initial phase value is taken to be the initial phase value of the immediately preceding speech frame encoded with the frequency-domain coding mode.

Abstract: A method, apparatus, and article of manufacture used to encode/decode a low activity communication signal—such as a Baudot tone—for transmission over a telecommunications system. The telecommunications system may include any number of wireless links. Once the system is noticed that a low activity signal needs to be transmitted, each vocoder used in the system to encode/decode the signal performs a unique encoding/decoding process. In one embodiment, frames containing errors adversely affecting a signal are delivered to the vocoder and the “soft bits” contained therein are used to determine the original signal transmitted. In another embodiment, encoding of the signal may include encoding the signal using redundancy with the encoded signal being spread across multiple vocoder frames.

Abstract: Controlling transmission energy in a variable rate communication system that gates out portions of a frame in a predetermined and predicable fashion. In particular, the present invention describes a method and apparatus which identifies closed loop power control commands that have been generated erroneously based on portions of a frame that have been gated. The identified power control commands are ignored. In an alternative embodiment, if identification of the erroneous power control commands occurs after response measures have been taken, the transmitting station responds by setting the transmission energy back to the state it would have been in had the erroneous power control commands been identified prior to the response.

Abstract: Systems and techniques for controlling transmission power involve receiving a first to second channel power ratio, receiving a first to second channel power ratio, adjusting the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels, and computing gain of the first channel as a function of the power ratio. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A method for permitting encrypted communications between two stations which are operable with encryption algorithms that accept encryption keys having work factors with different values, by: in a first determining step, determining the lower one of the different values; providing an initial encryption key having a first work factor value; comparing the first work factor value with the lower one of the work factors determined in the determining step; when, in the comparing step, the first work factor value is greater than the lower one of the work factor values determined in the determining step, performing the following steps: performing a first hash function on the initial encryption key to produce a first output, and deriving from the first output a first intermediate key having a work factor value not greater than the lower one of the different work factor values determined in the determining step; performing the first hash function on the first intermediate key to produce a second output, and deriving fro

Abstract: A method of modifying gain tables for the reverse-link communications in a cdma2000 wireless communication network includes the steps of estimating the velocity of a mobile station for a given frame error rate (FER) and data rate, and providing three gains to choose between based on the estimated velocity in order to specify a reverse-link transmit power level. The velocity estimation may be performed using a level crossing technique, a covariance approximation technique, or a Doppler spectrum estimation technique.

Abstract: A method is taught for improving the transmission of information signals in a communications system having a base station and a remote station. First and second transmission links are established with the remote station. An information signal is encoded to provide an encoded information signal having more bits than the information signal. First and second transmission signals are provided wherein each transmission signal has bits selected from the encoded information signal. Each of the first and second transmission signals is transmitted to the remote station by way of a respective one of the first and second transmission links. The remote station receives and combines the first and second transmission signals transmitted by the remote station to provide a combined encoded signal. The combined encoded signal is decoded by the remote station to provide the information signal.

Abstract: A method and an apparatus for generating encryption stream ciphers are based on a recurrence relation designed to operate over finite fields larger than GF(2). A non-linear output can be obtained by using one or a combination of non-linear processes to form an output function. The recurrence relation and the output function can be selected to have distinct pair distances such that, as the shift register is shifted, no identical pair of elements of the shift register are used twice in either the recurrence relation or the output function. Under these conditions, the recurrence relation and the output function also can be chosen to optimize cryptographic security or computational efficiency. Moreover, it is another object of the present invention to provide a method of assuring that the delay that results for the encryption process does not exceed predetermined bounds.

Abstract: In a communication system which conforms to the IS-99 standard, a concatenated code is used to provide for error free file transfer over the air. The concatenated code comprises Reed-Solomon coding, CRC block coding, and convolutional coding. The file is partitioned into data frames and Reed-Solomon encoding is performed on the data frames. CRC block encoding is then performed on the Reed-Solomon encoded data. The CRC encoded data is convolutionally encoded. The CRC block encoding and convolutional encoding are performed in accordance with the IS-99 standard. The additional Reed-Solomon encoding step provides improved error correction capability while maintaining compatibility with the IS-99 standard. At the receiver, Reed-Solomon decoding is performed if the number of erasures in a code word is less than or equal to (n−k) or the symbol errors in a code word is less than or equal to (n−k)/2. Otherwise, a request for retransmission is sent.

Abstract: A method and apparatus for generating an autonomous Pilot Strength Measurement Message (PSMM) by a mobile station traveling in a multi-carrier wireless communication system. In a multi-carrier system, the mobile station receives the pilot channel of a base station on multiple carrier frequencies simultaneously. Fading may vary from carrier frequency to carrier frequency. New pilot strength definitions are used by the mobile station in a set of rules transmitted by the base station. The set of rules determines autonomous generation and transmission of PSMMs by the mobile station upon detection of pilots.