Datang Mobile Communications Equipment Co., Ltd.

China Academy of Telecommunications Technology

Xiaolong Ran

Feng Li

Tiezhu Xu

Yingmin Wang

Yusong He

Libao Zhang

The invention discloses a space-time encoding and decoding method for a frequency selective fading channel, comprising: an encoder takes two independent data fields of a time slot in input data as a processing unit with space-time orthogonal encoding method, encodes them and generates two data vectors, thereby forming two diversity signals, and transmitting said two diversity signals simultaneously with each through one diversity antenna; a receiving terminal neglects mutual interference between said two diversity signals caused by non-orthogonality; the terminal performing joint detection only taking into account affect to said two diversity signals from multipath interference and multi-user interference, thereby obtaining a decoding result; and implementing interference counteraction based on result of joint diction to remove interference between the two diversity signals, and then returning to the previous step to implement iteration for decoding processing. The number of iteration times can be predefined. The invention takes an independent data field as a processing unit for encoding and decoding, and the decoding takes an iteration method based on joint detection and interference counteraction. This invention provides a simple and effective way for space-time encoding and decoding for a frequency selective fading channel.

Method of space-time encoding and decoding for frequency selective fading channel

The present invention discloses a method for detecting random access of User Equipment (UE), applicable to a mobile communication system consisting of at least one Base Station (BS) and a group of UEs; wherein the BS and the group of UE use a set of N (N is a positive integer) orthogonal or quasi-orthogonal pseudo-random sequence codes for UEs' random access. The method comprises: BS receiving a random access signal, and making correlation operation of the received signal with each pseudo-random sequence code in said code set successively to obtain a corresponding correlation result window; finding the maximum correlation peak in the correlation result window, and then dividing a correlation peak window and the front-side and rear-side windows thereof; setting one or more thresholds and comparing them with correlation results in the correlation peak window or in the correlation peak window and the front-side and rear-side windows; when conditions are satisfied, determining that the pseudo-random sequence code involved in the above correlation operation is the pseudo-random sequence code selected by the UE randomly accessed at the moment; thereby, detecting each randomly accessed UE.

Method for detecting random access of user equipment

The invention relates to a cell initial search method for user equipment (UE) in a CDMA digital cellular mobile communication system. The method includes: a UE after selecting a working frequency point, obtains downlink synchronization with the base station; and corrects carrier deviation between the UE and the base station. The downlink synchronization includes: deciding a range of downlink training sequence timeslot (DwPTS) based on training sequence power characteristic window value method; solving correlation of received data and training sequence in the range to obtain accurate receiving position of a UE. The correction of carrier deviation between a UE and the base station includes: estimating carrier deviation between a UE and the base station by software, recovering carrier frequency difference by using decision and feedback method to adjust hardware and carrier deviation correction method based on joint detection to correct carrier deviation.

Method for cell initial search in a CDMA mobile communication system

The invention relates to a method for improving smart antenna array coverage. Arbitrary beam forming of an antenna array can be implemented by adjusting n antenna units beam forming parameter W(n), based on difference of size and shape between coverage required in engineering design and actually realized coverage. The method includes: setting an accuracy of W(n), i.e. an adjusting step length, setting a set of initial values W (n), an initial value of mean-square error &egr; , setting counting variable, setting threshold of ending adjustment M and maximum emission power of an antenna unit T(n). With the settings, a loop for W(n) adjustment is executed. A step-by-step approximation method is deployed for adjusting antenna radiation parameters, based on the minimum mean-square error criterion. Finally, an actual coverage of an antenna array approximates to the required coverage, under local optimization condition.

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Beijing, China

Xiaolong Ran