Abstract: A communication system and receiver is provided that facilitates increased message size in a communication system that supports a large number of transmitters sharing a common frequency band. The communication system facilitates increased message size by incorporating a plurality of transmit bit sets in each burst of data. The additional transmit bit sets are incorporated into a plurality of transmit codes that are generated using at least one additional spreading code that is orthogonal to the base spreading code. The plurality of transmit codes are then combined into one composite message and the composite message is spread again using another scrambling sequence. The final composite spread message is transmitted to the receiver in the appropriate message time slot, resulting in CDM/TDMA burst signal that facilitates increased message size.

Abstract: Methods and apparatus are provided for coupling a satellite to an earth terminal. The apparatus inputs of the satellite that is configured to receive digital uplink signals, an autoscaling digital multiplexer of the satellite that is configured to digitally multiplex the digital uplink signals to produce a digital composite signal, and a digital modulator of the satellite that is configured to digitally modulate the digital composite signal to produce a digitally modulated composite signal. In addition, the apparatus comprises an input of the earth terminal that configured to receive the digitally modulated composite signal and a digital demodulator of the earth terminal that is configured to digitally demodulate the digitally modulated composite signal received by the input of the earth terminal to produce a second digital composite signal.

Abstract: Methods and apparatus are provided for coupling an earth terminal to a satellite The apparatus comprises multiple inputs of the earth terminal configured to receive multiple digital communication signals, a autoscaling digital multiplexer of the earth terminal configured to digitally multiplex the multiple digital communication signals to produce a digital composite signal, and a digital modulator of the earth terminal configured to digitally modulate the digital composite signal to produce a digitally modulated composite signal. In addition, the apparatus comprises an input of the satellite configured to receive the digitally modulated composite signal, and a digital demodulator of the satellite configured to digitally demodulate the digitally modulated composite signal received by the input of the satellite to produce a second digital composite signal.

Abstract: Methods and apparatus are provided for generating for generating a multiplexed communication signal in a wireless communication system. The apparatus comprises inputs configured to receive digital communication signals, a transform matrix configured to transform the digital communication signals into transformed digital communication signals, and a processor configured to generate a scaling vector for the transformed digital communication signals. Furthermore, the apparatus further comprises an operator configured to produce a mantissa for each of the transformed digital communication signals with the scaling vector and a multiplexer configured to multiplex the mantissa for each of the transformed digital communication signals and the scaling vector to produce the multiplexed communication signal.

Abstract: A transmitter adds packet transmission order information to transmitted packets using a forward error device (416) and a masking device (420). The masking device (420) receives ordering masks (610) from a mask store (424). The ordering masks (610) are maintained in a known order, and the ordering masks (610) and the known order are known to both the transmitter and the receiver. The receiver includes an unmasking device (504) that applies ordering masks to unmask the packets, and then an error detection device checks for errors. The ordering masks (610) are applied in the known order until errors are below an acceptable limit. When errors are below an acceptable limit, the relative packet order is determined from the known order of the ordering masks.

Abstract: Multiple format secure voice apparatus for communication handsets includes a core unit with a speaker, a microphone, a keypad, and a display. The core unit also includes an audio circuit coupled to the speaker and the microphone, an encryption/decryption element coupled to the audio circuit, a coder/decoder element coupled to the audio circuit and the encryption/decryption element, and a control element coupled to the keypad, the display, the audio circuit, the encryption/decryption element, and the coder/decoder element. A standard interface coupling is connected to an audio I/O terminal, a data I/O terminal of the coder/decoder element, and a control I/O terminal of the control element. A mating standard interface coupling mates with the standard interface coupling of the core unit and is coupled to the mating standard interface coupling.

Abstract: Methods and apparatus are provided for coupling a satellite to an earth terminal. The apparatus inputs of the satellite that is configured to receive digital uplink signals, an autoscaling digital multiplexer of the satellite that is configured to digitally multiplex the digital uplink signals to produce a digital composite signal, and a digital modulator of the satellite that is configured to digitally modulate the digital composite signal to produce a digitally modulated composite signal. In addition, the apparatus comprises an input of the earth terminal that configured to receive the digitally modulated composite signal and a digital demodulator of the earth terminal that is configured to digitally demodulate the digitally modulated composite signal received by the input of the earth terminal to produce a second digital composite signal.

Abstract: Methods and apparatus are provided for coupling an earth terminal to a satellite The apparatus comprises multiple inputs of the earth terminal configured to receive multiple digital communication signals, a autoscaling digital multiplexer of the earth terminal configured to digitally multiplex the multiple digital communication signals to produce a digital composite signal, and a digital modulator of the earth terminal configured to digitally modulate the digital composite signal to produce a digitally modulated composite signal. In addition, the apparatus comprises an input of the satellite configured to receive the digitally modulated composite signal, and a digital demodulator of the satellite configured to digitally demodulate the digitally modulated composite signal received by the input of the satellite to produce a second digital composite signal.

Abstract: Methods and apparatus are provided for generating for generating a multiplexed communication signal in a wireless communication system. The apparatus comprises inputs configured to receive digital communication signals, a transform matrix configured to transform the digital communication signals into transformed digital communication signals, and a processor configured to generate a scaling vector for the transformed digital communication signals. Furthermore, the apparatus further comprises an operator configured to produce a mantissa for each of the transformed digital communication signals with the scaling vector and a multiplexer configured to multiplex the mantissa for each of the transformed digital communication signals and the scaling vector to produce the multiplexed communication signal.

Abstract: Multiple format secure voice apparatus for communication handsets includes a core unit with a speaker, a microphone, a keypad, and a display. The core unit also includes an audio circuit coupled to the speaker and the microphone, an encryption/decryption element coupled to the audio circuit, a coder/decoder element coupled to the audio circuit and the encryption/decryption element, and a control element coupled to the keypad, the display, the audio circuit, the encryption/decryption element, and the coder/decoder element. A standard interface coupling is connected to an audio I/O terminal, a data I/O terminal of the coder/decoder element, and a control I/O terminal of the control element. A mating standard interface coupling mates with the standard interface coupling of the core unit and is coupled to the mating standard interface coupling.

Abstract: A receiver performs rapid adaptive interference canceling for use in despreading multiple CDMA channels sharing the same RF front end. The receiver includes a buffer (22) for providing for overlapping time samples and rate adaptation, a windowing function (24) for improving interference rejection capability and a FFT (26) for calculating the input power spectrum. The receiver further includes a circuit (28, 30) to whiten the input power spectrum. The whitened power spectrum is multiplied (32) against the frequency domain version of different spreading sequences and the inverse FFT (40) of the product is performed. The output of this inverse FFT is buffered (44) to provide multiple despread output channels, with a plurality of code phases for further processing.

Abstract: A subscriber unit (26) communicates with a satellite (12) using electromagnetic signals so that observations (102) of the signals are obtained. Surface contours are generated (104) based on the signal component measured. The surface contour intersections produce candidate locations on the earth's surface. The candidate locations seed a least-squares estimation to produce final locations. Data produced during the least-squares fit is used to generate confidence ellipses (116) about the final locations. Most likely actual locations are determined from the fit associated with the confidence regions. A variety of signal source measurements can be used while providing a best estimate of a signal source location when an exact solution is not mathematically possible. The location is converted to coordinates that can be used in a satellite communication system (10) for making decisions regarding the granting or denying of communication services, billing rate and the like.

Abstract: A finite impulse response filter performs an FFT on a signal, multiplies it by a transfer function in the frequency domain, and then performs an inverse FFT. The transfer function is dynamically computed in real-time by detecting signal energy in the frequency domain and turning off bins that contain the signal. The signal is delayed prior to turning off the bin in a FIFO memory by an amount equal to the time required to compute the transfer function. In this way, relatively fast changes in the interference environment can be tracked and rejected. For example, short duration narrow band interference signals in the presence of a wideband signal of interest, including direct sequence (DS) spread-spectrum signals in the presence of frequency hopped (FH) spread spectrum signals are rejected. The received signal quality of DS spread spectrum signals is improved.