摘要:
The present invention is a method and apparatus for voice communication. Vocoded frames are transmitted using a transmission intervals. Each transmission interval is split into a first interval portion and a second interval portion. Code symbols associated with each vocoded frame are divided into a group A and a group B. The method includes transmitting group A code symbols of a first vocoded frame using a first interval portion of an interval i; decoding the group A code symbols received at the first interval portion of the interval i; performing an error detection code check on the first interval portion of the interval i; generating and sending a negative acknowledgment signal when the first interval portion of the interval i fails the error detection code check; and transmitting group B code symbols of the first vocoded frame using a second interval portion of an interval i+N.
摘要:
Method and apparatus to provide a pseudo random noise (PN) sequence having a particular code phase offset for use in a radio in a Code Division Multiple Access (CDMA) radio system (100). In one embodiment, a first mask (320) is applied to shift a reference PN sequence to the assigned PN code phase (416). Upon reaching the end of the reference PN sequence, the initial state is reloaded (420) into the PN generator state register to reset the state value to its initial value, thereby producing a cyclical sequence. In a second embodiment, a first mask (622) and a second mask (624) are applied to the reference sequence produced by the PN generator state registers (620) to produce the appropriate portions of the output sequence.
摘要:
A receiver (200) is provided receiving signals from differing base stations (BTSA and BTSB). The signal from BTSA is encoded using a first rate convolutional encoder while the signal transmitted from BTSB is encoded using a second rate convolutional encoder. Since the multiple base station links may result in a different number of symbols being received for each bit transmitted, the symbols received for each link cannot be simply combined. Therefore, in the preferred embodiment of the present invention, the resulting symbols are passed to multiple branch metric circuits (210–211), where branch metrics (μi) for the symbols are obtained. After the ith branch metrics for the base stations are computed, the branch metrics for each base station are passed to a combiner (212) where they are combined.
摘要:
Multiple-configuration communication apparatus includes: a communication device (130) simultaneously maintaining at least a first and a second channel; a storage device (114, 116, 118) storing a plurality of communication configurations; and a configuration controller (120) determining a first time frame and during the first time frame, selecting a first communication configuration of the plurality of communication configurations and controlling the communication device to configure itself to the first communication configuration to at least one of transmit and receive information over the first channel, and determining a second time frame that is different from the first time frame and during the second time frame, selecting a second communication configuration of the plurality of communication configurations, and controlling the communication device to configure itself to the second communication configuration to at least one of transmit and receive information over the second channel.
摘要:
A communication band is divided into a plurality of allocation channels (202, 204, 206, 208). At least one allocation channel (204) is transferred to a transform domain. The behavior of the at least one allocation channel is monitored in the transform domain in order to derive a set of statistics. The set of statistics are used to determine a channel category for the at least one allocation channel.
摘要:
A method and apparatus to adaptively puncture bits within QAM modulated data symbols transmitted in a communication system in order to effect a signaling channel. The method and apparatus utilize inherent characteristics of a particular mapping scheme for the QAM constellation to selectively puncture particular bits within a data symbol with signaling information and predetermined binary values to selectively increase the log-likelihood ratio gains of those particular bits punctured with the signaling information. The log-likelihood ratios are used to obtain the signaling information and, thus, increasing the gain of the log-likelihood ratios affords greater reliability for the signaling information without increasing the required system resources.
摘要:
A method and apparatus to efficiently calculate log-likelihood ratios for each bit within M-ary QAM modulated symbols transmitted in a communication system. The method and apparatus utilize characteristics of square Karnaugh mapping of the QAM symbol constellation in order to reduce the number of distance calculations needed to determine the log-likelihood ratios for each of the bits within a demodulated symbol. The reduction in the number of calculations affords significant reduction in the time needed to determine log-likelihood ratios, especially for higher order M-ary QAM systems.
摘要:
A current mode of operation is provided to a Walsh spreader (203), and based on the current mode of operation, the Walsh spreader (203) either varies a Walsh code at a symbol rate, or holds the Walsh code constant. During multi-carrier transmission a first symbol within a data stream (210) is spread with a first Walsh code, while symbols immediately preceding and following the first symbol are spread by a another, differing Walsh code. The sequence of Walsh codes exiting the spreader (201) is further scrambled by a pair of Pseudo-Noise (PN) codes (224) that are held constant for three Walsh code periods during multi-carrier transmission, and are not held constant during direct-spread transmission.
摘要:
A transmitter (300) comprises summers (301-307, 3178-319), and mixers (309-315, 333). During multi-carrier transmission, multiple I and Q components enter the transmitter. I.sub.1 is summed with I.sub.3, Q.sub.3 is subtracted from Q.sub.1, Q.sub.1 is added to Q.sub.3, and I.sub.3 is subtracted from I.sub.1. The outputs of a first and a second summer (301, 305) enters a first and a second mixer (309, 313) where they are mixed by a cosine function. Similarly, the outputs of a third and a fourth summer (303, 307) enter a third and a fourth mixer (311, 315) where they are mixed by a sine function. The output from first and the second mixer (309, 311) enter a first summer (317) where they are summed along with the I.sub.2 component. The output from the third and the fourth mixer (313, 315) enters a second summer (319) where they are summed along with the Q.sub.2 component.
摘要:
One or more vehicle communication systems associated with one or more vehicles may be activated. The one or more vehicles may, for example, include a gateway vehicle. A backhaul connection between a vehicle communication system associated with the gateway vehicle and a cellular infrastructure may be established. Signals from the cellular infrastructure may be received at the vehicle communication system associated with gateway vehicle. Using the vehicle communication system associated with the gateway vehicle, the signals received from the cellular infrastructure may be transmitted. Signals from one or more mobile devices may be received using the vehicle communication system associated with the gateway vehicle. The signals received from the one or more mobile devices may be transmitted to the cellular infrastructure using the vehicle communication system associated with the gateway vehicle.