TD-SCDMA channel estimation method

Abstract

The invention relates to a channel identifying method for time division synchronous code division multiple access (TD SDMA), which applies the masking to the channel estimator which utilizes single cycle correlator with low complexity, thus increasing the predictable channel taps and increasing the efficiency of the receiver. The invention consists of the following steps: receiving, in which data comprising the midamble is received; calculating, in which the estimated channel value of a maximum of 16 chip delay is calculated by utilizing the midamble; masking, in which the estimated channel value corresponding to the middle code migration is masked to be 0; decoding, the data are decoded by utilizing the masked estimated channel value. Therefore, the identifying method has the advantages of relieving the limitation of the channel division of the joint channel estimator, gaining greatly in performance and complexity and improving the efficiency of the receiver.

Description

technical field [0001] The present invention relates to time division synchronous code division multiple access (TD-SCDMA), especially a kind of channel judgment method of time division synchronous code division multiple access, the method applies masking to the channel estimator using single period correlator with less complexity , which can increase the number of estimable channel taps and improve the efficiency of the receiver. Background technique [0002] In the third generation (3G) Time Division Synchronous Code Division Multiple Access (TD-SCDMA), the transmission length of a time slot (Time Slot) is 144 chips (Chip), and the period is 128. The code sequence, in the receiver, uses the above-mentioned midamble code sequence to perform channel judgment. [0003] Also, the intermediate code sequence assigned to each code is a sequence of basic intermediate codes shifted (shifted). That is, a midamble sequence having a midamble offset (offset) is assigned to each chann...

AI Technical Summary

Problems solved by technology

Therefore, there is a problem in previous TD-SCDMA, that is, when using a chip-level joint channel estimator, such as figure 2 As shown, the maximum number of channel taps is limited by the midamble offset (W). Since the sequences of the other users are different from those shifted like the actual first user's W, they have large correlation values, so in the joint channel Unable to get desired value when seeking inverse matrix in estimator

[0049] At the same time, there is also the following problem. When a channel path with a larger offset than the above-mentioned midamble is generated, the joint channel estimator cannot restore the channel path with a larger offset than the midamble

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