Abstract: This invention relates to a multiple access encoding method, which includes: expand the complete complementary orthogonal code mate to generate generalized complementary orthogonal code group, where the auto-correlation function of the generalized complementary orthogonal code group mentioned is the impulse response, and the cross-correlation function is zero everywhere; expand the generalized complementary orthogonal code group and the extension matrix to generate the expanded generalized complementary orthogonal code group; perform multiple access encoding to the transmitted data by using the expanded generalized complementary orthogonal code group and its shift code group. The invention also discloses a multiple-access transmission method, multiple access decoding method, multiple access coding equipment, multiple access transmission equipment, multiple access decoding equipment and the corresponding communication system.

Abstract: This invention provides a code division multiplexing method and system which include the following steps: constructing the basic grouping perfect orthogonal complementary code pair mate, modulating the C code and S code of the basic grouping perfect orthogonal complementary code pair mate to the M orthogonal carrier frequency or orthogonal polarization waves which are serially in time, and implementing continuous shift on the modulated basic grouping perfect orthogonal complementary code pair mate.

Abstract: The present invention provides the method and system of a Time Division Multiplexing which makes use of a number of symbols in the time domain transmitting data sequence in parallel. The method includes: the transmitting terminal forms the transmission signals which are overlapped by a number of symbols in the time domain, and the receiving terminal does data sequence detection in the time domain for the received signals according to the one-to-one relationship between the transmission data sequence and the time waveform of the transmission data sequence. In addition, the present invention also provides a kind of Time Division Multiplexing system based on the above method of the Time Division Multiplexing. The present invention makes actively use of these overlapping to produce the coding constraint relation, thus the spectral efficiency of the system is improved by a large margin.

Abstract: The present invention relates to a code multiplexing method which employs the parallel linear or nonlinear coding whose coding rate is more than one for the multiplexing transmission. When the coding rate is more than one, the parallel input bits sequence and the parallel output bits sequence have a one-to-one relationship. The aforementioned parallel coding method is beyond the finite field, and all the parallel coding polynomial set is coprime with each other. The method includes the following steps: compositing the encoding matrix B which contains K coding vectors, forming K parallel data transmission paths which correspond to the K coding vectors, processing the convolutional coding between each data path and the corresponding coding vector where the coding constraint length is L, forming the N-dimensional output vectors by summing the result of the K convolutional coding data paths, receiving the aforementioned N-dimensional coding output vectors and taking the sequence detection.

Abstract: The present invention provides a code division multiple address coding method which uses related random variables or some constants such as time, space and frequency as the coding element. The encoding procedure includes following steps: selecting the basic orthogonal perfect complementary dual code; selecting the basic time, space and frequency coding expansion matrix; constituting a perfect orthogonal complementary code pairs mate; expanding the length and the number of the code group in accordance with the law of spanning tree; completing the coding by transforming the spanning tree.

Abstract: This invention is a method about frequency multiplex. We employ numbers of sub-carriers whose frequency spectrum are overlapped each other to modulate the transmitted data sequences, and then we get the complex modulated signals. In the receiver point, we make use of one mapping between the overlapped signals' spectrum and the transmitted data sequences to detect the transmitted data sequences. By overlapping the adjacent sun-carriers, this invention can greatly increase the spectrum efficiency, and the more the multiplicity, the higher the spectrum efficiency. Furthermore, when the spectrum efficiency increases, the needed number of signal levels for this invention will not have exponential growth, just linear growth in stead, so the requirement for system linearity can be decreased greatly.

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 method for forming an orthogonal code group for use in a spread spectrum communication system is disclosed. The orthogonal code group can be formed by orthogonal rotation of a nonzero real number and complex number sequence. Multiple groups of orthogonal codes can also be obtained by orthogonal rotation of a given orthogonal code group as long as the given code group includes real number and/or complex number elements. Every code within a code group thus formed is substantially orthogonal with other codes within the code group. Furthermore, the code groups thus formed retain desirable characteristics of the initial code group.

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 the steps of generating a plurality of pluses, and generating a plurality of codewords. The plurality of pluses has a plurality of intervals between each of the pulses in the plurality of pulses, respectively. Each pulse of the plurality of pulses has an amplitude and a polarity. Each interval of the plurality of intervals is unequal to other intervals of the plurality of intervals. Only one interval of the plurality of intervals is an odd number larger than a value of a smallest interval of the plurality of intervals. No value of any interval in the plurality of intervals is a sum of any two or more values of two or more intervals, respectively, in the plurality of intervals.

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: A spread-spectrum system with a base station and a plurality of user equipment. The base station has a plurality of spread-spectrum transmitters. Each spread-spectrum transmitter spread-spectrum processes data with a particular code-division-multiple-access (CDMA) code from a plurality of CDMA codes to generate a particular spread-spectrum signal The particular CDMA code has a zero correlation window. The spectrum transmitter transmits the particular spread-spectrum signal over the communications channel using radio waves. The plurality of user equipment has a plurality of spread-spectrum receivers. Each spread-spectrum receiver spread-spectrum processes, from the communications channel, the particular spread-spectrum signal with the particular CDMA code from the plurality of CDMA codes, to obtain the data.

Abstract: Spread spectrum multiple access codes for use in a spread spectrum multiple access communications system and a method of generating such codes are disclosed. In one embodiment, an N-bit spread spectrum code is first transformed with an ideal periodic auto-correlation function to an orthogonal group of spread spectrum multiple access codes. Then, each code's length is extended by 2&Dgr; elements, where &Dgr; denotes a predetermined width of a desired zero-correlation window for the code's auto-correlation function. The extended codes can be used for the spread operation, and the non-extended codes can be used for the de-spread operation.

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: A spread-spectrum receiver using a spread-spectrum multiple-access codes in the area of wireless communications system that involves code-division-multiple access (CDMA) and spread-spectrum technology. The spread-spectrum receiver uses two orthogonal, synchronous fading channels to transmit two pairs of multiple access spreading codes respectively. The two pairs of spreading codes oppose each other but also complement each other in the transmission so that their correlation has a property of zero correlation window, i.e. the auto-correlation and cross-correlation functions have no side lobes within the zero correlation window. That means that inter symbol interference (ISI) and MAI will be completely eliminated in the corresponding CDMA and spread-spectrum system, so that makes it possible to build a wireless digital communications system of large RF capacity and solve the more severe contradictions between the resource of frequency efficiency and RF capacity.

Abstract: A spread-spectrum transmitter using a spread-spectrum multiple-access codes in the area of wireless communications system that involves code-division-multiple access (CDMA) and spread-spectrum technology. The spread-spectrum transmitter uses two orthogonal, synchronous fading channels to transmit two pairs of multiple access spreading codes respectively. The two pairs of spreading codes oppose each other but also complement each other in the transmission so that their correlation has a property of zero correlation window, i.e. the auto-correlation and cross-correlation functions have no side lobes within the zero correlation window. That means that inter symbol interference (ISI) and MAI will be completely eliminated in the corresponding CDMA and spread-spectrum system, so that makes it possible to build a wireless digital communications system of large RF capacity and solve the more severe contradictions between the resource of frequency efficiency and RF capacity.

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 pluses, and a plurality of codewords. The plurality of pluses 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: 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.