Abstract: A transmitter and a receiver using a set of Large-Area Code-Division-Multiple-Access (LA-CDMA) codes. The LA-CDMA codes are generated from a plurality of pulses, and a plurality of codewords. The plurality of pulses has a plurality of intervals between each of the pulses. Each pulse has an amplitude and a polarity. Each interval is unequal to other intervals of the plurality of intervals. Only one interval is an odd number larger than a value of a smallest interval of the plurality of intervals. No value of any interval is a sum of any two or more values of two or more intervals, respectively, in the plurality of intervals. Each codeword is different from other codewords in the plurality of codewords. The plurality of codewords are either orthogonal, or bi-orthogonal, or trans-orthogonal.

Abstract: A framing method and the synchronous wireless system therewith, wherein the method includes the steps of: partitioning the data stream into frames according to the frame length, in which the number of sub-frame in each frame can be determined by the periodicity of selected LA codes; forming each sub-frame by a plurality of time slots, in which the number of the said time slots can be determined by the number of pulses of the said LA codes, and the said time slot length varies with the variation of the pulse interval of the said LA codes; and filling in each time slot by modulation with the selected orthogonal spread spectrum codes. Different base stations from different, nearby cells shall be assigned different LA-CDMA codes so that adjacent cell interference can be reduced. While in nearby cells, the same spreading code can be assigned, therefore greatly reducing requirement for the number of spreading codes, as well as the requirement for the lengths of the spreading codes.

Abstract: In accordance with the present invention, a method is provided for a mobile station to select one cell site in a plurality of cell sites in cellular systems with an Interference Free Window. This method is based on measurement of the signal on the downlink. In preferred embodiments, a mobile station receives the downlink spread spectrum signals from a plurality of neighboring cells. By using a RAKE type correlator or matched filter, the signal energy and the multipath delay spread profile can be estimated at the mobile station. A new function is defined as the ratio of the multipath delay spread to the energy of the received signal. Minimizing the said function will result in a cell site that provides the best quality of service in a multipath propagation environment.

Abstract: A reverse synchronization method, which is used in a wireless system utilizing orthogonal spreading codes with Interference Free Window characteristic, wherein the transmission time of the signal from a remote unit is adjusted with respect to a predetermined Interference Free Window [−n, +n], such that the arrival time in a base station of the signal from the said remote unit falls within the said predetermined Interference Free Window. This eliminates inter-symbol interferences and multiple access interferences when multipath signals from a same remote unit and signals from different remote units arrive within an Interference Free Window.

Abstract: This invention publishes a spread spectrum multiple access coding technique applied in any wireless digital telecommunication system involving Code Division Multiple Access and spread spectrum technique. The group of basic pulses has normalized amplitudes and duration of 1 and polarity; the number of basic pulses is ascertained by practical factors; there is no equal interval between basic pulses on time axis, and asymmetry of pulses' positions is employed to achieve arranging coding. This coding scheme can control and minimize the side lobes of auto-correlation and cross-correlation functions, then simplify the design of a CDMA system, so a wireless digital telecommunication system with large capacity can be established effectively to solve the contradiction between ever increasing demand for telecommunication capacity and limited frequency resources.

Abstract: This invention publishes a spread spectrum multiple access coding technique applied in any wireless digital telecommunication system involving Code Division Multiple Access and spread spectrum technique. The group of basic pulses has normalized amplitudes and duration of 1 and polarity; the number of basic pulses is ascertained by practical factors; there is no equal interval between basic pulses on time axis, and asymmetry of pulses' positions is employed to achieve arranging coding. This coding scheme can control and minimize the side lobes of auto-correlation and cross-correlation functions, then simplify the design of a CDMA system, so a wireless digital telecommunication system with large capacity can be established effectively to solve the contradiction between ever increasing demand for telecommunication capacity and limited frequency resources.