Space-frequency coding-based multi-antenna transmitter diversity method and system thereof

Abstract

The invention relates to the mobile communication field, disclosing a space frequency coding based multi-antenna transmission diversity method and the system thereof. When the number of transmission antenna is over 2, a coding can be accomplished within an OFDM symbol period and meanwhile a diversity gain similar to STTD+CSD can be obtained. The invention uses space frequency coding to obtain the diversity gain and at the same time introduces phase offset in the frequency-domain to obtain extra frequency diversity similar to CSD through the channel of the frequency-domain data. The phase offset satisfies: the frequency-domain data loaded in the sub-carrier wave set used in SFTD on the same antenna possesses the same phase offset and the frequency-domain data loaded between the sub-carrier wave sets possesses different phase offsets. Moreover, the frequency-domain data loaded on the same sub-carrier wave on different antenna in the same antenna stack possesses different phase offsets.

Description

technical field [0001] The invention relates to the field of mobile communication, in particular to the diversity technology of mobile communication. Background technique [0002] Wireless communication can expand the scope of communication and information sharing, and at the same time provide greater flexibility for business, its status is becoming more and more important, and its application range is becoming more and more extensive. With the development of wireless communication, users have put forward higher and higher requirements for its transmission rate and service quality, but the further development of wireless communication is limited due to the lack of wireless spectrum resources. In addition, the multipath and time-varying characteristics of wireless channels It will cause great damage to the signal transmitted in it, and these two problems have become obstacles to the development of wireless communication, which is faced with the problem of how to improve the u...

AI Technical Summary

Problems solved by technology

[0028] Existing technical solution 1 simply uses STBC to realize transmit diversity, which has the following unavoidable defects: first, when the number of transmit antennas is greater than 2, the encoding rate is less than 1, and at the same transmission rate, it is equivalent to a higher channel encoding rate. Therefore, when the channel coding rate is already high, it may cause a large performance loss; second, when the transmitting antenna is greater than 2, it takes 4 or 8 symbol periods to complete one coding, because the cycle to complete one coding is longer , the channel may change during the encoding cycle, affecting the orthogonality of space-time coding, resulting in a decrease in performance; third, due to the different numbers of transmitting antennas, the encoding matrix and decoding algorithm are different, so the flexibility is achieved lower

[0046] Existing technology solution 2 simply using OFDM-based CSD to achieve diversity also has some unavoidable defects: first, channel coding is required to obtain frequency diversity gain; second, although CSD can guarantee a coding rate of 1, it can be seen that , CSD cannot obtain full diversity gain, and the diversity performance is not as good as STBC; third, inappropriate delay values ​​will cause some frequency points with a certain delay to respond to 0, resulting in a punching effect and affecting the performance of the decoder

[0060] Although the existing technical solution 4 can complete one encoding within one OFDM symbol, when the number of antennas is greater than 2, it is impossible to use CSD to achieve frequency diversity gain

Images