Downlink data transmission method, system and equipment

Abstract

The invention discloses a downlink data transmission method, a downlink data transmission system and downlink data transmission equipment, which relate to the field of wireless communication and are used for improving data transmission reliability and saving air-interface resources. The method comprises that: a base station allocates physical resource blocks (PRB) to a terminal according to channel quality indicator (CQI) information reported by the terminal and the current volume of downlink data to be transmitted; the base station determines a first modulation and coding scheme (MCS) level, wherein the first MCS level is lower than a second MCS level which is an MCS level determined according to signal-to-interference and noise ratios (SINR) on each PRB allocated to the terminal; the base station searches for an MCS form and a transport block size (TBS) form to obtain a TBS corresponding to the first MCS level and the total number of the PRBs allocated to the terminal; and the base station transmits the downlink data of the TBSs to the terminal by utilizing the PRBs allocated to the terminal. By the method, the system and the equipment, the data transmission reliability can be effectively improved, the repeat probability of a hybrid automatic repeat request (HARQ) can be reduced, and the wasting of air-interface resources can be effectively reduced.

Description

technical field [0001] The present invention relates to the field of wireless communication, in particular to a downlink data transmission method, system and equipment. Background technique [0002] In a Long Term Evolution (LTE) system, a Physical Radio Resource Block (PRB) is a basic resource allocation unit, and is used for resource allocation of a Physical Downlink Shared Channel (PDSCH) and a Physical Uplink Shared Channel (PUSCH). A PRB is defined as N in the time domain symb UL consecutive Orthogonal Frequency Division Multiplexing (OFDM) symbols and N in the frequency domain sc RB consecutive subcarriers, such as figure 1 shown. Downlink N in LTE system symb UL and N sc RB The value of is given in Table 1. It can be known from Table 1 that, under a regular CP, a regular PRB includes 84 resource units (REs are the smallest resource granularity unit), and a regular PRB pair (PRB Pair) includes 168 REs. [0003] Table 1 [0004] [0005] When determining...

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Problems solved by technology

It can be seen from Table 5 that when the two PRB pairs allocated by the eNodeB scheduler are both punctured PRB pairs (the above situation will definitely occur when the bandwidth is 1.4M and the subframe is 0), the actual code rates are all If it is greater than 0.93, or even greater than 1, the detection performance of the UE on service data is degraded or even errors occur, which greatly reduces the reliability of service data transmission, and the HARQ retransmission caused by errors greatly wastes air interface resources

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