The communication system includes a hybrid fiber/coax distribution network. A head end provides for downstream transmission of telephony and control data in a first frequency bandwidth over the hybrid fiber/coax distribution network and reception of upstream telephony and control data in a second frequency bandwidth over the hybrid fiber/coax distribution network. The head end includes a head end multicarrier modem for modulating downstream telephony information on a plurality of orthogonal carriers in the first frequency bandwidth and demodulating upstream telephony information modulated on a plurality of orthogonal carriers in the second frequency bandwidth. The system includes service units, operatively connected to the hybrid fiber/coax distribution network for upstream transmission of telephony and control data and for receipt of the downstream control data and telephony. Also provided is a method and apparatus for performing a Fast Fourier Transform (FFT).

Communication system with multicarrier telephony transport

A method and apparatus for controlling transmission power levels in a mobile communication system. The method provides for a closed-loop power control method. A mobile station provides information on the quality of the signal received from the base station, and the base station responds by adjusting the power allocated to that user in a shared base station signal. The transmission power is adjusted initially by a large increment and then ramped down at an increasingly decreasing rate. The mobile station also provides information to the base station as to its relative velocity and the base station adjusts its transmission power in accordance with this velocity information.

Method and apparatus for performing fast power control in a mobile communication system

Techniques for canceling pilot interference in a wireless (e.g., CDMA) communication system. A received signal typically includes a number of signal instances (i.e., multipaths). For each multipath desired to be processed, the other multipaths act as interference on the desired multipath. If the pilot is generated based on a known data pattern (e.g., all zeros) and covered with a known channelization code (e.g., a Walsh code of zero), then the pilot in an interfering multipath may be estimated as the spreading sequence at a time offset corresponding to the arrival time of that multipath. The pilot interference from each interference multipath may be estimated based on the spreading sequence for the interfering multipath and the despreading sequence for the desired multipath. The total pilot interference from a number of interfering multipaths may be subtracted from the data component in the desired multipath to provide pilot-canceled data having improved performance.

Method and apparatus for canceling pilot interference in a wireless communication system

Spread spectrum receiver architectures and methods are described for reducing interference, particularly the interference observed at a user-end terminal in a W-CDMA 3G mobile communications system. Interpath interference which arises due to non-zero cross and auto correlation of more than one spreading code is suppressed by estimating a transmitted signal stream, or a plurality of such signal streams in the case of a plurality of multipath components, respreading this estimated signal and subtracting non-orthogonal interference contributions from a received signal. The techniques provide an improved bit error rate or equivalently, enhanced capacity for a digital mobile communications network.

Receiver processing systems

A disk drive has a normal mode of operation and a built-in self-test (BIST) mode of operation for producing a sequence of channel metrics {Γ n }. The disk drive includes a recording surface having a plurality of bit cells and a transducer for reading the plurality of bit cells to produce a noise-corrupted read signal. The disk drive further includes means responsive to the noise-corrupted read signal for generating a sequence of observed samples {y n }, the sequence of observed samples {y n } forming a sequence of observed-sample subsequences {Y n }. An expected sample generator operates during the BIST mode of operation to provide a sequence of expected samples {w n }, the sequence of expected samples forming a sequence of expected-sample subsequences {W n }. A channel metrics Γ n computation system computes a sequence of channel metrics {Γ n }. Each channel metric Γ n is a function of a distance determined from one of the observed-sample subsequences Y n to the corresponding expected-sample subsequence W n . Each channel metric Γ n is independent of the earliest observed sample in every prior observed-sample subsequence Y n and the earliest expected sample in every prior expected-sample subsequence W n .

Disk drive having built-in self-test system for characterizing performance of the drive

A system and method for canceling interference present in a code-division multiple access (CDMA) channel signal received at a CDMA receiver that is caused by multipath components of a transmitted pilot channel signal or by soft handoff conditions is computationally efficient because it operates at symbol rates. The channel signal from which such multipath interference is canceled can be either a traffic (data) channel or the pilot channel itself. Interference signals are produced in groups corresponding to the fingers of the CDMA rake receiver. The interference signals corresponding to each finger are used to cancel interference in the other fingers.

Interference suppression in a cdma receiver

A method determines the transmission quality of a signal transmitted by a base station and received by a mobile station in a cellular digital radio telephone network. The mobile station determines the phase error of detected bits a the input of the channel decoder, calculates the average and variance of the phase error. The average and variance are used to calculate the S/N ratio. The S/N ratio information is transmitted to a base station which converts the S/N ratio to a value defining the BER estimate of the received signal.

Method to determine transmission quality

A wireless telecommunications mobile station, which is bi-directionally coupled to a base station through a communication channel, includes a device for receiving signals over the communication channel from the base station, power control circuitry for selectively deriving power control commands, and a device for transmitting the selectively derived power control commands to the base station. The power control circuitry of the mobile station provides, in cooperation with power control circuitry of the base station, closed loop power control to the communication channel. The power control circuitry includes circuitry for selectively deriving power control commands based on one of first power control commands or second power control commands in response to a determined mobility of the mobile station. The determined mobility can be indicative of a Doppler shift of carrier transmitted from the base station, or a velocity derived from the Doppler shift.

Forward link closed loop power control for a third generation wideband CDMA system

Power control apparatus (88), and an associated method, for controlling communication signals generated during operation of a communication system, such as an IS-953G cellular communication system. Determinations are made as to whether a communication channel (16) upon which communication signals are transmitted exhibits a deep fade condition. If a determination of a deep fade condition is made, power control is effectuated to reduce the power levels of communication signals subsequently transmitted on the communication channel.

Apparatus, and associated method, for effectuating power control of a communication device

A wireless telecommunications mobile station (10), which is bidirectionally coupled to a base station (30) through a communication channel (29), includes a device (64) for receiving signals over the communication channel from the base station, power control circuitry (18a) for selectively deriving power control commands, and a device (74) for transmitting the selectively derived power control commands to the base station. The power control circuitry of the mobile station provides, in cooperation with power control circuitry of the base station, closed loop power control to the communication channel. The power control circuitry includes circuitry (70, 72) for selectively deriving power control commands based on one of first power control commands or second power control commands in response to a determined mobility of the mobile station. The determined mobility can be indicative of a Doppler shift of carrier transmitted from the base station, or a velocity derived from the Doppler shift.

Antti Kansakoski

Papers

Interference suppression in a cdma receiver

Method to determine transmission quality

Forward link closed loop power control for a third generation wideband CDMA system

Apparatus, and associated method, for effectuating power control of a communication device

Forward link closed loop power control based on mobile station mobility