Abstract: For a transmission system in which (a) a received sequence of symbols is processed by an inner decoder followed by an outer decoder and (b) the inner decoder is capable of providing to the outer decoder more than one output sequence corresponding to the received sequence, the decoded sequence released by the outer decoder is screened for errors undetected by the outer decoder, if a predetermined criterion is satisfied.

Abstract: In a system for simulcasting digitally modulated and analog FM signals over the same FM frequency band, the effect of the analog FM signal on the digitally modulated signal in the simulcast is calculated and canceled from the latter signal before its transmission. As a result, the digital transmission is free from interference from the analog FM signal. Moreover, the digital transmission is achieved by adaptively inserting a time varying number of carriers modulated by digital data into the FM band. The carriers are selected frame by frame to control their interference with the analog FM signal. In accordance with the invention, the carriers are selected in a predetermined order, and in a preferred embodiment grouped contiguously with one another in the FM band. As a result, the rate of control information required to identify the inserted carriers to a receiver is advantageously low.

Abstract: We have invented methods of and devices for introducing unequal error protection into spread spectrum communication systems. One embodiment of the invention addresses certain inefficiencies of the standard known as IS-95 used, for example, in some mobile direct sequence code division multiple access ("DS-CDMA") phone systems. The invention allows for increased system capacity and/or improved quality. More specifically, spread spectrum multiple access ("SSMA") coding may be combined with the concept of unequal error protection ("UEP"), resulting in an UEP SSMA coding process. IS-95, in order to make significant portions of a signal highly immune to errors, has imposed the same high degree of error immunity on less significant portions of the signal (when, in fact, a lower degree would suffice) and, thus, wastes bandwidth. The present invention's coding process (i.e., UEP SSMA) utilizes bandwidth in a closer to optimal manner than known methods.

Abstract: In a system for simulcasting a digitally modulated signal and an analog FM signal over the same FM frequency band, the composite signal is received and applied to a conventional FM receiver, and a digital receiver in accordance with the invention. An extended Kalman filter is employed in the digital receiver to estimate the analog FM signal based on a version of the recovered FM signal from the FM receiver, and a discrete version of the composite signal whose spectrum has been translated and is at an intermediate carrier frequency. The estimated FM signal, which is in a discrete form, is subtracted from the discrete version of the composite signal. The resulting signal, which is an estimated version of the digitally modulated signal, is demodulated to recover the digital data as transmitted.

Abstract: A belt for use on a long nip press for dewatering a fibrous web includes a base assembled by spirally winding a prepared structure strip in a plurality of non-overlapping turns. Successive turns are abutted against and joined to those previously wound by sewing or otherwise bonding along the continuous spiral seam thus formed. The prepared structure strip may be a fabric strip woven from lengthwise and crosswise yarns, which may be monofilament yarns of a synthetic polymeric resin. The fabric strip may be of either a single- or multi-layer weave. At least one side of the base, namely, that side which will be on the inside of the belt in its endless loop form, and which slides over the arcuate pressure shoe component of the long nip press during its operation, is coated with a polymeric resin, such as polyurethane, to render it impervious to liquids, and especially to the oil used to lubricate the surface of the arcuate pressure shoe.

Abstract: A method and device are disclosed that utilize a spread spectrum coding process for processing a signal having first and second time portions to achieve unequal error protection of the time portions by variably modulating the power of one segment relative to the second segment. In such a signal, the first segment contains information that is more significant, i.e., more sensitive to error, than the second segment and the power modulator increases the average power of the signal during the first time portion relative to the average power of the signal during the second time portion. Preferably, the power increase of the first time portion is proportional to the power decrease of the second time portion so as to maintain overall system power requirements. The method and device are particularly suited for a digital cellular telephone systems such as DS-CDMA. In such a system, the signal is spread by a single spreading sequence.

Abstract: A belt for use on a long nip press for dewatering a fibrous web includes a base assembled by spirally winding a prepared structure strip in a plurality of non-overlapping turns. Successive turns are abutted against and joined to those previously wound by sewing or otherwise bonding along the continuous spiral seam thus formed. The prepared structure strip may be a fabric strip woven from lengthwise and crosswise yarns, which may be monofilament yarns of a synthetic polymeric resin. The fabric strip may be of either a single- or multi-layer weave. At least one side of the base, namely, that side which will be on the inside of the belt in its endless loop form, and which slides over the arcuate pressure shoe component of the long nip press during its operation, is coated with a polymeric resin, such as polyurethane, to render it impervious to liquids, and especially to the oil used to lubricate the surface of the arcuate pressure shoe.

Abstract: A method and system for reducing co-channel interference (CCI) in multiple access communication by providing complete or partial cancellation of a mixed CCI interfering signal in a system base station. An exemplary system includes first and second base stations communicating with users in first and second cells, respectively. The first base station transmits a downlink signal to a user in the first cell. The downlink signal is also a mixed CCI interfering signal in that it interferes with reception of an uplink signal in the second base station. A cancellation signal representative of the interfering signal is supplied along a transmission path from the first base station to the second base station. The second base station utilizes the cancellation signal to reduce the effect of the interfering signal on a received composite signal by, for example, combining the cancellation signal or a suitably processed version thereof with the received composite signal.

Abstract: We have invented methods of and devices for introducing unequal error protection into spread spectrum communication systems. One embodiment of the invention addresses certain inefficiencies of the standard known as IS-95 used, for example, in some mobile direct sequence code division multiple access ("DS-CDMA") phone systems. The invention allows for increased system capacity and/or improved quality. More specifically, spread spectrum multiple access ("SSMA") coding may be combined with the concept of unequal error protection ("UEP"), resulting in an UEP SSMA coding process. IS-95, in order to make significant portions of a signal highly immune to errors, has imposed the same high degree of error immunity on less significant portions of the signal (when, in fact, a lower degree would suffice) and, thus, wastes bandwidth. The present invention's coding process (i.e., UEP SSMA) utilizes bandwidth in a closer to optimal manner than known methods.

Abstract: A method for effecting error protecting coding in digitally modulated analog information as a function of the quality of transmission characteristics in the communication channel is provided in which the error code is embodied in the source code word, such as by reducing the number of significant bits and substituting error protecting code bits. This results in the maintenance of transmission capacity while providing the space needed for the redundant signals required to preclude error.

Abstract: The invention refers to heat weld joints of the type used for adjoining webs of reinforced plastic foil intended for use as stretched ceiling covers. The invention consists in the provision of means at intervals along the heat weld joints for reinforcing same to withstand the influence of heat. The invention also covers a process for the preparation of such reinforced heat weld joints.

Abstract: The knife assembly consists essentially of a relatively light two-edged cutting insert and a heavier holder. The insert is symmetrical about its longitudinal axis. In cross-section the two cutting edges of the insert represent the acute corners of a parallelogram, the obtuse corners of which are occupied by two longitudinal grooves that are hook-shaped in cross section. The holder includes a base plate having a projection complementary to either of said grooves. A clamping plate secures the insert on the base plate and binds said projection and said hook-like groove together. In the assembled knife the cutting edge of the insert is bounded by two plane surfaces one of which is flush with a plane surface on the holder and the other of which is flush with a plane surface on the clamping plate.