Abstract: A method of multicarrier modulation using co-located transmitters to achieve higher transmission capacity for mobile paging and two-way digital communication in a manner consistent with FCC emission mask limits. Co-location of the transmitters obviates the need for stringent, symmetrical subchannel interference protection and provides for a wider range of operating parameters, including peak frequency deviation, bit rate, and carrier frequencies, to obtain optimal transmission performance.

Abstract: An improved tubing rotator is mounted to the casing bowl of a well, for rotating a tubing string extending down the well. A swivel dognut assembly is provided, comprising inner and outer sleeves. The tubing string is suspended from the inner sleeve which is rotatably supported from the stationary outer sleeve. The outer sleeve is adapted to be suspended from the tapered inner surface of the casing bowl, and is restrained from vertically upwards displacement by holddown screws. The outer sleeve is almost entirely contained or recessed within the casing bowl. A housing is bolted onto the casing flange. A pair of worms extend through the housing and driveably engage a ring gear associated with the inner sleeve. Because the sleeves are seated in the casing bowl, a compact rotator assembly is obtained.