Abstract:
An apparatus, software modem, and method for a data communications device, such as a modem (100, 101), to determine a symbol rate and carrier frequency, from a received probe signal, for optimizing a bit rate for data transmission and reception. The various embodiments utilizing a processor (108) or a digital signal processor (106) receive a probe signal, which also typically contains noise and other distortions, particularly envelope delay distortion. The various method and apparatus embodiments then determine a variance of the envelope delay distortion, either directly or indirectly as a correlate of attenuation distortion or as a correlate of a selected transmit pre-emphasis filter specified under the ITU V.34 protocol. The variance of the envelope delay distortion is then utilized to eliminate or disable certain symbol rates and corresponding carrier frequencies in the determination of an optimal symbol rate and carrier frequency for data transmission and reception.
Abstract:
A radio receiver (700) uses automatic frequency control for locking a controlled reference signal (108) to a pilot reference signal (114) that has been distorted by multipath fading. The radio receiver (700) is programmed to sample the pilot reference signal (114) over a predetermined time interval to determine an average pilot frequency, and applies a first weighting function to the average pilot frequency to generate a weighted pilot frequency and a second weighting function to a controlled frequency of the controlled reference signal (108) to generate a weighted controlled frequency. The radio receiver (700) sums the weighted pilot frequency with the weighted controlled frequency to provide an update frequency, and modifies the controlled reference signal (108) such that its frequency matches the update frequency. The radio receiver (700) continues these programmed steps so as to lock the controlled reference signal (108) to the pilot reference signal (114).
Abstract:
An SCT (Selective Call Transceiver) (10) includes a memory (54) which stores a list (60) of addressees with whom the SCT user normally communicates. The memory also stores, for each of selected addressees, an associated group (62) of customized messages. The SCT (10) has a processor (18) that is programmed to permit the user to easily choose a customized message to be sent to an addressee, either by way of replying to a previously received message or by initating transmission of a new communication.
Abstract:
An apparatus for placing at least one biological reagent at a plurality of locations on a substrate includes a stamp member onto which the at least one biological reagent is applied. The stamp member defines a plurality of transfer elements patterned to correspond to the plurality of locations. The stamp member contacts the substrate to transfer the at least one biological reagent from the plurality of transfer elements to the plurality of locations. The transfer elements can be defined by reservoirs or projected portions of the stamp member.
Abstract:
A method and apparatus is used for securing programming information in communication device (100). The apparatus comprises a read-only memory (116) containing a current serial number normally expected to be unchanged from an original serial number pre-programmed into the read-only memory (116), the original serial number being unique to the communication device (100). The apparatus further includes a non-volatile memory (114) having stored therein a current stored value normally expected to be unchanged from an original stored value derived from the original serial number. The processor (108) is programmed, in response to an occurrence of a predetermined event, to compare a first comparison value derived from the current serial number with a second comparison value derived from the current stored value, and allow an operation of the communication device (100) in response to the first comparison value matching the second comparison value.
Abstract:
An encryption server receives a first encrypted message (105) and decrypts (403) the encrypted message using a first key, yielding a decrypted message comprising a second encrypted message (105A), an identification of a sender of the first encrypted message, and an identification of a first recipient. The second encrypted message, the identification of the sender, and the identification of the first recipient are determined (405) from the decrypted message. The second encrypted message and the identification of the sender are encrypted (409) with a second key, yielding a third encrypted message (109). The third encrypted message (109) is transmitted to the first recipient.
Abstract:
A frequency synthesizer (200) with temperature compensation and frequency multiplication. The synthesizer (200) having a temperature uncompensated frequency oscillator (202) coupled to a phase locked loop (206) including at least one temperature compensating and frequency multiplication element (208). The element (208) preferably being a multi-modulus divider. The element (208) is programmed by a control circuit (210) to vary as a function of temperature and to vary as a function of a fractional frequency multiplication factor. The element (208) also may provide adjustment of the nominal frequency of the frequency oscillator (202). The frequency oscillator (202) and preferably all the elements of the synthesizer (200) are temperature-compensated by the element (208) to produce a multiplied and temperature-compensated frequency output.
Abstract:
A tonal sound recognizer determines tones in a tonal language without the use of voicing recognizers or peak picking rules. The tonal sound recognizer computes feature vectors for a number of segments of a sampled tonal sound signal in a feature vector computing device (120), compares the feature vectors of a first of the segments with the feature vectors of another segment in a cross-correlator (130) to determine a trend of a movement of a tone of the sampled tonal sound signal, and uses the trend as an input to a word recognizer (140) to determine a word or part of a word of the sampled tonal sound signal.
Abstract:
An electrochemical cell (10) is provided with first (20) and second (30) electrodes, and a solid polymer electrolyte (40) disposed therebetween. The electrodes may either be of the same or different materials and may be fabricated from ruthenium, iridium, cobalt, tungsten, vanadium, iron, molybdenum, nickel, silver, zinc, and combinations thereof. The solid polymer electrolyte is in intimate contact with both the anode and the cathode, and is made from a polymeric support structure having dispersed therein an electrolyte active species. The polymer support structure is preferably a polybenzimidazole.