The phrase "across transmit" is not correct and does not make sense in written English.
It seems to be an attempt to convey a meaning related to communication or transmission, but it lacks clarity and proper usage.
Example: "We need to find a better way to transmit information across the network."
Alternatives: "send across" or "communicate through".
The overall ppSNR for configuration j is determined as the average across transmit antennas and subcarriers.
In other words, the level of nonlinear distortion is smallest when data subcarriers are equally allocated across transmit antennas.
At first, some problems pertaining to the implementation of the conventional per-subcarrier antenna selection approach, including power imbalance across transmit antennas and noncausality of antenna selection criteria, are identified.
In [11], the results are extended to MIMO frequency-selective fading channels, and it is revealed that training signals across transmit antennas should be orthogonal and training signals should be equi-powered.
By applying ZF beamforming across transmit antennas, up to users can receive data over mutually orthogonal beams under the assumption of ideal channel knowledge at both the transmitter and receiver and sufficient spatial separation of the users.
A group channel correlation matrix estimate from a single frequency response can now be formed averaging across transmit and receive antennas, and groups, R ~ h g min = 1 N T N R N g min ∑ i = 1 N T ∑ j = 1 N R ∑ g = 1 N g min h ̄ g ij ( k ) ( h ̄ g ij ( k ) ) H. (58).
All the existing beamforming designs in [1 19] were developed under a sum-power constraint across all transmit antennas.
In such systems, space-time transmission is typically implemented using a linear space-time matrix, or equivalently a linear precoder, so that a single modulation symbol is efficiently transmitted across multiple transmit antennas.
Assuming that the information symbol vector at each antenna is of size M, we stack the symbols transmitted across K transmit antennas as shown below x ~ n ≜ vec ( [ x ~ n, 1 x ~ n, 2 … x ~ n, K ] ), (1).
On one hand, spreading across space (transmit antennas) and frequency (subcarriers) potentially provides robustness against frequency-selective fading and channel ill-conditioning while providing transmit diversity gains.
