Abstract: A method of identifying a target mobile transceiver in a communications network that includes multiple unknown mobile transceivers. In this aspect of the method, a location system interrogates the target mobile transceiver multiple times in an interrogation pattern to cause the target mobile transceiver to transmit a signal in response to each interrogation. The location system monitors signals transmitted by all mobile transceivers in the network, and identifies the target mobile transceiver as the mobile transceiver whose pattern of response most closely matches the interrogation pattern.

Abstract: MultiCode Spread Spectrum (MCSS) is a modulation scheme that assigns a number N of Spread Spectrum (SS) codes to an individual user where the number of chips per SS code is M. When viewed as Direct Sequence Spread Spectrum, MCSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of NM operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e. interference between the N SS codes. In this patent, we introduce three new types of MCSS. MCSS Type I allows the information in a MCSS signal to be detected using a sequence of partial corrrelations with a combined complexity of the order of M operations. MCSS Type II allows the information in a MCSS signal to be detected in a sequence of low complexity parallel operations which reduce the ICI.

Abstract: MultiCode Spread Spectrum (MCSS) is a modulation scheme that assigns a number N of Spread Spectrum (SS) codes to an individual user where the number of chips per SS code is M. When viewed as Direct Sequence Spread Spectrum, MCSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of NM operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e. interference between the N SS codes. In this patent, we introduce three new types of MCSS. MCSS Type I allows the information in a MCSS signal to be detected using a sequence of partial corrrelations with a combined complexity of the order of M operations. MCSS Type II allows the information in a MCSS signal to be detected in a sequence of low complexity parallel operations which reduce the ICI.

Abstract: The position of a Wireless Transceiver (WT) is estimated using the Time Of Arrival (TOA) at several Monitoring Sites (MS) of the signal transmitted by the WT. Several sites are used to solve for the coordinates of the WT using hyperbolic trilateration. A time reference is used to synchronize the Monitoring Sites (MS). Super-Resolution (SR) techniques are applied to increase the resolution of the TOA estimate obtained via correlation of the received signal at each MS. SR techniques can improve the TOA resolution substantially.

Abstract: One way to increase the bandwidth efficiency of a linear modulation scheme is to increase the number M of possible signaling levels. Such an increase is achieved however at the expense of a smaller minimum distance d.sub.min between the multilevels, for a fixed average signal power. The present invention involves the use of a conversion filter as part of a digital signaling system used over a communications channel of limited bandwidth and power. A conventional linear digital signaling system consists of an encoder, a shaping filter, a modulator and a bandpass filter. In the present invention, the digital signaling system consists of an encoder, a conversion filter, a modulator and a passband filter. The conventional filter increase the bandwidth efficiency of the scheme when its impulse response spreads over L signaling intervals. Such an increase is achieved however, at the expenses of a smaller d.sub.min. By increasing the modulation index h of the conversion filter, it is possible to increase d.sub.min.

Abstract: In this patent, we present MultiCode Direct Sequence Spread Spectrum (MC-DSSS) which is a modulation scheme that assigns up to N DSSS codes to an individual user where N is the number of chips per DSSS code. When viewed as DSSS, MC-DSSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of N2 operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e., interference between the N DSSS codes. In this patent, we introduce new DSSS codes, which we refer to as the “MC” codes. Such codes allow the information in a MC-DSSS signal to be decoded in a sequence of low complexity parallel operations which reduce the ICI. In addition to low complexity decoding and reduced ICI.

Abstract: In this patent, we present MultiCode Direct Sequence Spread Spectrum (MC-DSSS) which is a modulation scheme that assigns up to N DSSS codes to an individual user where N is the number of chips per DSSS code. When viewed as DSSS, MC-DSSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of N.sup.2 operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e., interference between the N DSSS codes. In this patent, we introduce new DSSS codes, which we refer to as the "MC" codes. Such codes allow the information in a MC-DSSS signal to be decoded in a sequence of low complexity parallel operations which reduce the ICI. In addition to low complexity decoding and reduced ICI. MC-DSSS using the MC codes has the following advantages: (1) it does not require the stringent synchronization DSSS requires, (2) it does not require the stringent carrier recovery DSSS requires and (3) it is spectrally efficient.