Slow-Fading Precoding for Multi-Cell Wireless Systems
Methods and apparatuses for slow-fading precoding for multi-cell wireless systems are provided. At a base station of a cellular network, the base station serving a pluralities of same-cell terminals and other-cell terminals, and the cellular network including other base stations that serve respective pluralities of same-cell terminals and other-cell terminals, a plurality of slow-fading coefficients are obtained, wherein each of the plurality of slow-fading coefficients is associated with channel state information for communication between one of the other base stations and one of the respective same-cell terminals or other-cell terminals. A set of slow-fading precoding coefficients are generated for transmitting signals to same-cell terminals and other-cell terminals based on the plurality of slow-fading coefficients.
1 . A method performed by a base station of a cellular network, the base station serving pluralities of same-cell terminals and other-cell terminals, and the cellular network including other base stations that serve respective pluralities of same-cell terminals and other-cell terminals, the method comprising:
receiving a plurality of slow-fading coefficients, each of the plurality of slow-fading coefficients being associated with channel state information for communication between one of the other base stations and one of the respective same-cell terminals or other-cell terminals; and
generating a set of slow-fading precoding coefficients for transmitting signals to same-cell terminals and other-cell terminals based on the plurality of slow-fading coefficients.
2 . The method of claim 1 wherein generating the set of slow-fading precoding coefficients comprises performing an iterative function to determine optimized slow-fading precoding coefficients.
3 . The method of claim 2 wherein each optimized slow-fading precoding coefficient is determined based on maximizing a minimum signal to interference and noise ratio for transmitting a signal to same-cell terminals and other-cell terminals.
4 . The method of claim 2 further comprising terminating the iterative function based on a precision control threshold.
5 . The method of claim 2 wherein the iterative function includes a quasi-convex optimization algorithm.
6 . The method of claim 1 further comprising:
obtaining pilot signals from the plurality of terminals; and
beam-forming signals to one or more of the plurality of same-cell terminals and other-cell terminals based on the set of slow-fading precoding coefficients.
7 . The method of claim 6 wherein the beam-forming is based on a set of fast-fading coefficients.
8 . The method of claim 6 wherein the beam-forming is performed using OFDM modulation.
9 . The method of claim 1 further comprising transmitting the set of slow-fading precoding coefficients to one of the other base stations.
10 . The method of claim 1 further comprising transmitting the set of slow-fading precoding coefficients to a processing center module.
11 . A base station apparatus for serving pluralities of same-cell terminals and other-cell terminals in a cellular network, the base station apparatus comprising:
a receiver module adapted for obtaining a plurality of slow-fading coefficients, each of the plurality of slow-fading coefficients being associated with channel state information for communication between another base station and one of a plurality of same-cell terminals or other-cell terminals; and
a precoding module adapted for generating a set of slow-fading precoding coefficients for transmitting signals to same-cell terminals and other-cell terminals based on the plurality of slow-fading coefficients.
12 . The base station apparatus of claim 11 wherein generating the set of slow-fading precoding coefficients comprises performing an iterative function to determine optimized slow-fading precoding coefficients.
13 . The base station apparatus of claim 12 wherein each optimized slow-fading precoding coefficient is determined based on maximization of a minimum signal to interference and noise ratio for transmitting a signal to a same-cell terminals and other-cell terminals.
14 . The base station apparatus of claim 12 wherein the precoding module is further adapted for terminating the iterative function based on a precision control threshold.
15 . The base station apparatus of claim 12 wherein the iterative function includes a quasi-convex optimization algorithm.
16 . The base station apparatus of claim 11 further comprising:
the receiver module adapted for obtaining pilot signals from the plurality of terminals; and
a beam-forming module adapted for beam-forming signals to one or more of the plurality of same-cell terminals and other-cell terminals based on the set of slow-fading precoding coefficients.
17 . The base station apparatus of claim 16 wherein the beam-forming is based on a set of fast-fading coefficients.
18 . The base station apparatus of claim 16 , wherein the beam-forming is performed using OFDM modulation.
19 . The base station apparatus of claim 11 further comprising a transmitter module adapted for transmitting the set of slow-fading precoding coefficients to one of the other base stations.
20 . The base station apparatus of claim 11 further comprising a transmitter module adapted for transmitting the set of slow-fading precoding coefficients to a processing center module.