Abstract: A wireless receiver includes a variable attenuator, a signal-to-noise ratio (SNR estimator), and a received signal strength indicator (RSSI) level detector. The RSSI level of the received signal is used as a primary criterion on setting the attenuator status. Once the attenuator is set based upon the RSSI readings, an SNR check is made to determine the possible presence of IM. Then, further adjustment on the attenuator status is made according to the SNR check.

Abstract: A demodulator of a CDMA base station receiver comprises a bank of 64 noncoherent Walsh correlators, each of which are identified by an index value and provide a correlator output signal to a soft decision metric generator. The soft decision metric generator provides a decision metric, D.sub.k, as a function of the L highest energy correlator output signals and their corresponding index values, where L>1.

Abstract: A distributed processing telephone system for providing "plug-and-play" capability. In particular, a key telephone system comprises a plurality of telephone sets. Each telephone set is coupled to a least one common communications channel, or telephone line, and includes at least one tunable RF modem. There is no key service unit (KSU). That is, the system is KSU-less. Resources of the telephone system are allocated using a peer-to-peer protocol. For example, as each telephone set is newly added to the system, the new telephone set adaptively determines its own allocation of resources, e.g., intercom numbers, etc. During operation, each telephone set requests the appropriate resources from its peers.

Abstract: A head-end dynamically allocates bandwidth of a communications channel as a function of the type of communications traffic. In particular, the head-end communicates to subscriber stations via a broadband cable network using an access protocol, which is modified to provide a variable number of mini-slots and a variable number of data slots in each frame. Each mini-slot is used to request assignment of a data slot(s) to subscriber stations for the communication of information and, also, as a vehicle to resolve contention between subscriber stations. The head-end dynamically adjusts the number of mini-slots over a period time as a function of the type of communications traffic, e.g., bursty and isochronous traffic sources. Any variation in the number of mini-slots concomitantly effects the number of data slots available to communicate information. For example, less mini-slots provides more data slots.

Abstract: A digital cellular/personal communications service (PCS) application incorporates a logical link connection (LLC) server. In this approach, there are two ATM connections in the path of an AAL-2 connection: one between a base station and the LLC Server and the other between the LLC Server and a vocoder group. All LLCs from, or to, a given base station use a common ATM connection irrespective of the vocoder used at the other end. Similarly, all LLCs from, or to, a given vocoder group use a common ATM connection irrespective of the destination base station at the other end. At the LLC Server, LLC packets from many base stations destined for the same vocoder group are extracted and bundled into the ATM connection between the LLC Server and the destination vocoder group. Similar treatment is given to the packets originating at vocoders and destined for base stations.

Abstract: A generalized form of a multimodulus algorithm (GMMA) is described for use in blind equalization. A receiver uses a signal point constellation representing 256 levels. This signal space is divided into sample, or data, subsets. Cost function minimization is done with respect to each sample subset.

Abstract: A distributed processing telephone system for providing "plug-and-play" capability. In particular, a key telephone system comprises a plurality of telephone sets. Each telephone set is coupled to a least one common communications channel, or telephone line, and includes at least one tunable RF modem. There is no key service unit (KSU). That is, the system is KSU-less. Resources of the telephone system are allocated using a peer-to-peer protocol. For example, as each telephone set is newly added to the system, the new telephone set adaptively determines its own allocation of resources, e.g., intercom numbers, etc. During operation, each telephone set requests the appropriate resources from its peers.

Abstract: A distributed processing telephone system for providing "plug-and-play" capability. In particular, a key telephone system comprises a plurality of telephone sets. Each telephone set is coupled to at least one common communications channel, or telephone line, and includes at least one tunable RF modem. There is no key service unit (KSU). That is, the system is KSU-less. Resources of the telephone system are allocated using a peer-to-peer protocol. For example, as each telephone set is newly added to the system, the new telephone set adaptively determines its own allocation of resources, e.g., intercom numbers, etc. During operation, each telephone set requests the appropriate resources from its peers.

Abstract: In an embodiment of the invention, a speaker/microphone peripheral includes a digital-signal-processor (DSP) based acoustic echo canceler and supports a plurality of modes of operation. One mode is a video/telecommunications mode. In this mode, when headphones are inserted or removed, the acoustic echo canceler is reset.

Abstract: A blind equalization cost function called the "constrained Hilbert cost function" (CHCF) provides for reliable blind convergence of a two-filter equalizer structure. In particular, the CHCF cost function is designed in such a way that the two filters are constrained to be a Hilbert pair. Advantageously, this technique can be used with any blind equalization algorithms, such as RCA, CMA, and MMA.

Abstract: A digital audio broadcasting (DAB) system includes a radio-frequency (RF) transmitter and a corresponding RF receiver. The RF transmitter transmits an RF DAB signal that includes a pilot signal at 250 Khz. An RF section of the RF receiver includes a phase-lock-loop (PLL) to compensate for any carrier frequency differences in the received RF DAB signal. This PLL tracks the phase of the received RF DAB signal when an amplitude of a recovered IF signal is above a predetermined threshold and upon detection of the pilot signal.

Abstract: A timing technique for a Quantization-Level-Sampling (QLS) modem puts timing information in a downstream pulsed signal transmitted from the public switched telephone network (PSTN) to the QLS modem. In response to this timing information, the QLS modem synchronizes to the network sampling clock in the PSTN. In particular, the pulsed signal includes data-bearing samples, which were provided by a far-end QLS modem, and at least one non-user-data-bearing (NUDB) sample in which the level of this NUDB sample periodically alternates. The QLS modem extracts timing information from this periodic alternating signal level to synchronize the QLS modem to the network sampling clock.

Abstract: A digital audio broadcasting system incorporates a perceptual audio coder that encodes a digital audio signal for broadcast. A "source label" is provided by controlling the perceptual audio coder in such a way that the number of coefficient samples, n, used in each transmission frame represents information about the source. For example, if the value of n is odd, then a binary "1" is transmitted, but if the value of n is even, then a binary "0" is transmitted. As a result, a low-bit rate "source label" is transmitted over a number of frames. In a receiver, the source of the digital audio signal is identified by simply monitoring the value of n over the number of frames. More importantly, the value of n in each frame is required by a corresponding perceptual audio decoder, in the receiver, to correctly recover the digital audio signal.