Abstract: The transmit power of a mobile station on the reverse link channel that carries channel state information, rate selection, and/or sector selection information is power controlled separately from the reverse link traffic channels when the mobile station is in soft handoff. The serving base station in the active set for the mobile station controls the mobile station transmit power on the rate control channel. The non-serving base stations control the transmit power on the reverse traffic channel.

Abstract: A wireless receiver, such as in a mobile station or base station within a wireless communication network, estimates the frame error rate (FER) for one channel using signal information received on another, associated channel. As such, FER estimates may be generated for a channel of interest during discontinuous periods of that channel, or where the duty cycle of the channel is too low to support a desired FER estimation rate. Signal information received on the associated channel is manipulated as needed to conform to the format of the channel of interest, such as the encoding format, and then decoded as if it had been received on the channel of interest. Thus, the signal information is treated as virtually encoded data for the channel of interest, and may comprise essentially any type of signal that is known or determinable, such as a pilot, synchronization, traffic, or control channel.

Abstract: Mobile terminals in a high data rate CDMA system may be placed in a control hold mode wherein reverse link control channels are gated, or transmitted at a reduced duty cycle. Mode decisions are based on the activity of the mobile terminal in both the forward and reverse links. A forward link inactivity timer is maintained at the base station that schedules forward link communications to a mobile terminal. The reverse link inactivity timer may be maintained at the same base station, at a different base station in the mobile terminal's active set, or at the base station controller. The forward link inactivity timer may follow the mobile terminal's selection of best forward link serving base station in handoff. When both the forward and reverse link inactivity timers have expired, and no forward link data is pending, the mobile terminal may be commanded to a control hold mode.

Abstract: A call admission policy is provided that has a dynamic operating point setting desired load levels for data calls and for voice calls. A request for a first call admission may be granted even though the desired load levels are exceeded if there is sufficient power to admit at least one additional second call, wherein the first call is selected form the group of data or voice calls and the second call is the remaining type of call within the group.

Abstract: A CDMA system in which the base stations transmit a synchronization channel comprising a primary subchannel from which slot synchronization is determinate and a secondary subchannel containing a cyclic hierarchical code unique for each base station and for each slot in a frame. The cyclic code is derived from a first code unique to a base station and a different cyclic shift of a second code also unique to the base station in each slot of a frame. Mobile stations quickly and with low-complexity detectors determine slot synchronization from the primary subchannel and then determine base station identification and frame synchronization by correlating samples of signal received on the secondary subchannel with a set of first codes and cyclic shifts of corresponding second codes.

Abstract: In a wireless communications system, after a high data rate user is admitted and a supplemental channel is assigned to the user, a control message is sent to a receiver to communicate for power ramp-up and ramp-down profiles. The control message contains parameters of a data rate, a starting time and a duration of time as group in assigned fields in the message which is provided by a control signal source. In response to the control message, a controller provides a rate controllable signal with reference to the parameters of the control message to a data encoder. A bursty input data stream is fed to a buffer. The data encoder withdraws the data from the buffer in response to the rate controllable signal. The bit rate transitions in the bursty input data stream are smoothed with reference to the parameters. There is provided an output data stream having smoother data rate transitions than the input data stream.

Abstract: Mobile terminals in a high data rate CDMA system may be placed in a control hold mode wherein reverse link control channels are gated, or transmitted at a reduced duty cycle. Mode decisions are based on the activity of the mobile terminal in both the forward and reverse links. A forward link inactivity timer is maintained at the base station that schedules forward link communications to a mobile terminal. The reverse link inactivity timer may be maintained at the same base station, at a different base station in the mobile terminal's active set, or at the base station controller. The forward link inactivity timer may follow the mobile terminal's selection of best forward link serving base station in handoff. When both the forward and reverse link inactivity timers have expired, and no forward link data is pending, the mobile terminal may be commanded to a control hold mode.

Abstract: A wireless receiver, such as in a mobile station or base station within a wireless communication network, estimates the frame error rate (FER) for one channel using signal information received on another, associated channel. As such, FER estimates may be generated for a channel of interest during discontinuous periods of that channel, or where the duty cycle of the channel is too low to support a desired FER estimation rate. Signal information received on the associated channel is manipulated as needed to conform to the format of the channel of interest, such as the encoding format, and then decoded as if it had been received on the channel of interest. Thus, the signal information is treated as virtually encoded data for the channel of interest, and may comprise essentially any type of signal that is known or determinable, such as a pilot, synchronization, traffic, or control channel.

Abstract: In a CDMA cellular radio system during soft handoff the base stations interpret the conventional power control commands sent by the mobile station according to a majority vote thus reducing the probability of responding to an erroneous power control command. Alternatively, during soft handoff every other power control command received is deliberately ignored. The base stations also synchronize their power levels periodically resulting in more optimum base station power transmission levels, in turn resulting in a reduction in system noise and an increase in system capacity.

Abstract: The invention relates to systems and methods for receiving signals modulated with a carrier frequency, wherein the signals include spreading chip sequences having at least one zero. The invention includes a method of receiving and despreading spread spectrum signals wherein the spread spectrum signals include spreading chip sequences having at least one zero and at least one non-zero chip. The method includes receiving and sampling a spread spectrum communication signal. The receiver generates a despreading code which is synchronized with the sampled spread spectrum communication signal. The sampled spread spectrum communication signal is then despread with the despreading code by omitting at least one operation involving at least one zero chip. The invention further includes a receiver configured to receive signals modulated with a carrier frequency over a channel, wherein the signals include spreading chip sequences having at least one zero.

Abstract: The transmit power of a mobile station on the reverse link channel that carries channel state information, rate selection, and/or sector selection information is power controlled separately from the reverse link traffic channels when the mobile station is in soft handoff. The serving base station in the active set for the mobile station controls the mobile station transmit power on the rate control channel. The non-serving base stations control the transmit power on the reverse traffic channel.

Abstract: A wireless communication network reduces its signaling overhead by recognizing when a mobile station transitions from an inactive state, such as Control Hold or quasi-active, back to an active state. Based on such recognition by the network, the mobile station begins sending desired traffic data without need for explicitly negotiating its return to active state, thereby reducing or eliminating higher-layer signaling, e.g., Layer 3 and above, that is otherwise required for return to active state operations. The network might further avoid explicit signaling by, for example, using transmitted reverse link Power Control Bits to indicate that an inactive mobile station should remain inactive. In this manner, inactive mobile stations may be allowed to return to active state without explicit signaling where appropriate, or held in the inactive state if needed, all without need for explicit network signaling.

Abstract: Methods and apparatus for generating spreading codes in a CDMA system are disclosed in accordance with the teachings of the present invention wherein the system includes a pseudonoise (PN) code generator and a logic device configured to replace a portion of a PN code generated by the PN code generator with at least one zero or to add at least one zero to a PN code generated by the PN code generator. The PN code generator generates a PN code made up of chips. One or more of these chips may be replaced by zeros or one or more zeros may be inserted between chips. Thus, when combined at a chip level with a substantially orthogonal code such as a Walsh code the resulting spreading code will be less effected and in some instances not effected at all by certain time delays inserted into the system (i.e time lag from multi-path dispersive transmissions).

Abstract: In a parallel concatenated convolutional code (PCCC) or turbo code encoder, information bits are supplied to a first convolutional code encoder for producing first parity bits and via an interleaver to a second convolutional code encoder for producing second parity bits, the output of the encoder comprising the information bits and at least some of the first and second parity bits. The interleaver interleaves the information bits in groups each of N bits, where N is an integer greater than one. A parity bit generator can generate additional parity bits which are operated on by the convolutional code encoders and interleaver. A complementary decoder is described. The grouped interleaving can provide reduced memory requirements and faster convergence of the iterative decoding process.

Abstract: The BER is used as a parameter for evaluating the performance of an optical transmission system. Performance of optical systems is also defined by the Q factor, which uniquely determines the BER in the absence of distortion. The measurements are effected in a point of operation of the channel which gives a value of interest for the Q factor. To this end, the optical SNR is lowered by adding noise over the information signal. A distortion-free Q (Q.sub.DF) and a back-to-back Q (Q.sub.BB) are determined in the same operating point of the system. The distortion penalty for transmitter-receiver pair may be determined by comparing Q.sub.DF to Q.sub.BB. The noise loading technique will allow to investigate if equalizing. The value of OSNRs at the output of a particular system results in equalizing the noise margin in that systems or not.

Abstract: A method and apparatus for channel performance equalization in wavelength division multiplexed (WDM) systems is disclosed. Performance of the channels is estimated from optical power measurements of each signal transmitted by the channels. The measurements are taken at the inputs of optical amplifiers in the transmission path of the system. The channels are equalized by adjusting the optical power of the channel transmitters. The method is applicable to point-to-point networks as well as more complex network configurations such as those having an add-drop multiplexer (ADM) for inserting and extracting channels from the transmission path. The method can compensate for signals having different bit rates by applying an offset to the amount of optical power adjustment of the channel transmitters.

Abstract: The BER is used as a parameter for evaluating the performance of an optical transmission system. Performance of optical systems is also defined by the Q factor, which indicates the signal-to-noise ratio of the electric signal regenerated by the receiver. In the absence of distortion, Q is univocally determined by the BER. Q is calculated using an estimated BER measured with the path under normal conditions of operation, and a distortion-free Q is determined in the same operating point of the system. The distortion penalty for the path is obtained by comparing the measured Q with the distortion free Q. In addition, the distortion penalty for a transmitter-receiver pair, and a distortion penalty for a transmission link between the transmitter and receiver may be determined.

Abstract: Bidirectional WDM transmission at 2.5 Gb/s using a bidirectional erbium-doped fiber amplifier (EDFA) is demonstrated over a distance of 300 km. A symmetrical EDFA configuration with a frequency tunable reflection attenuator is used as a bidirectional amplifier. Experimental results show that the allowable gain of the EDFA can be increased significantly while the associated bit error rate BER penalty remains negligible.