Jhong Sam Lee

Author:

Jhong S. Lee

ISBN #:

0890069905

US Patent:

6377555, Apr 23, 2002

Filed:

Sep 22, 1998

Appl. No.:

09/151797

Inventors:

Jhong Sam Lee - Potomac MD 20854
Leonard E. Miller - Kensington MD 20895

International Classification:

H04J 1300

US Classification:

370252

Abstract:

A method for determining the amounts of channel powers in the orthogonally multiplexed forward link of a CDMA cellular telephone or PCS system required to provide sufficiently high signal levels for these channels at the location of a mobile telephone receiver at or near the edge of the cell. The method first formulates the power requirements for the several types of forward link channels as a system of equations in the with the powers as variables, parametric in several parameters, including the number of active traffic channels, that vary with time. The method then proceeds to solve the system of equations to determine time varying powers of the pilot, synchronization, and paging channels; it also determines a value of the required power for a traffic channel that is useful for initializing the existing closed loop forward traffic channel power control of the system.

US Patent:

6385435, May 7, 2002

Filed:

Apr 20, 2000

Appl. No.:

09/552882

Inventors:

Jhong Sam Lee - Rockville MD 20850

International Classification:

H04B 714

US Classification:

455 24, 455 63, 4552781

Abstract:

A coupled interference cancellation system (CICS) for canceling retransmission-antenna-to-receiving-antenna (coupled) interference signals. The system is connected to a bidirectional, over-the-air repeater for a wideband digital cellular communication system. For each repeater direction, the CICS injects one or more modulated pilot signals at the retransmission antenna input which are emitted along with the communications signal. The portion of the repeater output signal that is coupled to the receiving antenna is indicated by the properties of the pilot signals that are detected at the repeaters receiving antenna. The detected quadrature components of the pilot signals are used to generate a cancellation signal by vector modulation and delay of a sample of the retransmission antenna input. The cancellation signal is applied at the receiving antenna output to subtract the coupled interference.

US Patent:

6556555, Apr 29, 2003

Filed:

Sep 14, 1999

Appl. No.:

09/395159

Inventors:

Leonard E. Miller - Kensington MD
Jhong Sam Lee - Potomac MD

Assignee:

J.S. Lee Associates, Inc. - Rockville MD

International Classification:

H04J 1302

US Classification:

370335, 370203

Abstract:

A method and program for determining the PN generator mask which is required to obtain a specific shift of the PN sequence at the output of a phase shift network (PSN), relative to the reference sequence that is represented by the inverse of the characteristic polynomial of the PN sequence. The method applies for any initial loading (state) of the PN generator, which can be either the simple shift register generator (SSRG) type or the modular shift register generator (MSRG) type of linear feedback shift register (LFSR). The application of the present invention includes, but is not limited to, any code division multiple access (CDMA) cellular telephone system which requires a method for generating specific shifts of a given reference PN sequence for each base station and each mobile station in the network.

US Patent:

63204614, Nov 20, 2001

Filed:

May 12, 2000

Appl. No.:

9/570339

Inventors:

Jhong Sam Lee - Rockville MD

International Classification:

H03F 366

US Classification:

330 52

Abstract:

A feedforward high power linear amplifier for wideband cellular applications uses slope compensation in combination with two modulated pilot signals to control intermodulation distortion cancellation stages in order to effect a much higher degree of linearity than can be achieved with conventional feed forward linear power amplifier designs.