摘要:
There are provided spread spectrum signal generating devices and methods in a transmitter of a mobile communications system using a plurality of logical channels. In the spread spectrum signal generating devices, a multiplexer time multiplexes a pilot channel signal and a control channel signal which are output at substantially constant power levels. A first orthogonal encoder orthogonally spreads the output of the multiplexer with an orthogonal code. A second orthogonal encoder orthogonally spreads voice channel data of a variable bit rate with an orthogonal code. A third orthogonal encoder orthogonally spreads packet channel data of a variable bit rate with an orthogonal code. An IQ signal mapper adds the outputs of the first and third orthogonal encoders, outputs the added signal as a first channel signal, and outputs the output of the second orthogonal encoder as a second channel signal. A PN spreader spreads the first and second channel signals with PN codes and outputs a final spectrum spread signal, which exhibits a substantially minimized peak-to-average power ratio.
摘要:
A device and method for generating a pseudo-orthogonal code for use in orthogonally spreading channel data in a CDMA mobile communications system. M orthogonal codes are selected from N orthogonal codes, for forming a pseudo-orthogonal codes, and the elements of the selected M orthogonal codes are sequentially interlaced to generate the pseudo-orthogonal code as a sequence of M×N elements.
摘要:
A code set generating method in a mobile communications system having Nf frequency channels and Np phase channels. In the method, a code length Nc is obtained by Nf×Np, a minimum distance Nd between codewords in a code set and frequency diversity Nfd are determined, code sets are detected according to Nc, Nd, and Nfd, a code set is selected, which shows such a Hamming distance distribution among code words that minimizes demodulation errors from the detected code sets, and the code set is stored in a mapping table of a demodulator.
摘要:
A forward link device of a multicarrier CDMA communication system with an overlay scheme in which a multicarrier system and an IS-95 system share same frequency bands. In the forward link device, four encoders encode input data of corresponding rates with a 1/3 coding rate, respectively. A first repeater repeats two times full rate symbols output from the first encoder, and second to fourth repeaters repeat symbols output from the second to fourth encoders, respectively, according to a predetermined number of times, to match the number of corresponding output symbols to the number of full rate symbols. First to fourth interleavers interleave the symbols output from the first to fourth repeaters, respectively, to uniformly distribute the symbols of the same data bit to the carriers.
摘要:
In a transmission device and method for a CDMA communication system, when a shorter frame message is generated during transmission of a longer frame message, the transmission of the longer frame message is interrupted, whereupon the shorter frame message is immediately transmitted in place of a portion of the longer frame message. In one embodiment, after the longer frame message is interrupted and the shorter frame message is transmitted, only the tail portion of the longer frame message is transmitted thereafter. That is, the replaced portion of the longer frame message is not transmitted following the shorter frame message transmission. In an alternative embodiment, following the shorter frame message transmission, the remainder of the longer frame message, from the point of interruption, is transmitted in its entirety. In the latter case, the longer frame message is delayed by the length of the shorter frame message.
摘要:
A method of initializing a packet traffic channel in a communication system to efficiently use channel capacity in a packet data service and to reduce time and power required to initialize a packet traffic channel includes timing alignment between a terminal and a base station, controlled access collision between terminals, use of preamble patterns, and a comb-type correlator branch.
摘要:
Method and apparatus for providing a packet data service between a terminal and a base station in a mobile communication system includes packet data being transmitted from the terminal (base station) on a reverse (forward) packet traffic channel to the base station (terminal) during a data transmission period; the occupation of the reverse (forward) packet traffic channel is released during a data transmission suspension period; and the base station controls the reverse (forward) packet traffic channel over a packet control channel.
摘要:
A device for time alignment on a reverse link in a CDMA mobile communication system. A base station stores a reference sync channel RTD (Round Trip Delay), calculates the difference between the reference sync channel RTD and a measured sync channel RTD, and outputs a time alignment control signal on a forward control channel when the calculated RTD error exceeds a predetermined value, during a data communication. A terminal receives the time alignment control signal on the forward control channel and time aligns a reverse traffic channel based on the received time alignment control signal.
摘要:
In a transmission device and method for a CDMA communication system, when a shorter frame message is generated during transmission of a longer frame message, the transmission of the longer frame message is interrupted, whereupon the shorter frame message is immediately transmitted in place of a portion of the longer frame message. In one embodiment, after the longer frame message is interrupted and the shorter frame message is transmitted, only the tail portion of the longer frame message is transmitted thereafter. That is, the replaced portion of the longer frame message is not transmitted following the shorter frame message transmission. In an alternative embodiment, following the shorter frame message transmission, the remainder of the longer frame message, from the point of interruption, is transmitted in its entirety. In the latter case, the longer frame message is delayed by the length of the shorter frame message.
摘要:
A power control bit inserting method between a base station and a terminal. The base station and the terminal each use a plurality of adjacent frequency bands as signal paths with independent signal paths of a real part and an imaginary part given to each frequency. In the power control bit inserting method, a unit time is set to a power control group period, n-bit data is allocated to each signal path, the power control group period is divided by the number of signal paths, and a power control bit is inserted in each divided segment, so that the insertion positions in the real and imaginary parts of each frequency are spaced from each other by n/2 bit and the start position of the real signal path of each frequency is inserted at an appointed bit position of the corresponding frequency.