Spatial mode adaptation at the cell edge using interferer spatial correlation

摘要

A system and method is proposed for adapting the spatial transmission strategy in a cellular MIMO (multiple input multiple output) communication system for the downlink. Spatial mode adaptation, the choice of multiplexing, transmit diversity, number of streams, space-time code family, and the like are performed slowly based on side information from other base stations. Base stations exchange their transmission plans with neighboring base stations and broadcast this information to active users. Each user measures its susceptibility to spatial interference and returns this information to the base station. The base station then schedules active users according to the decisions made in interfering base stations and the preferred transmission strategies of its own users.

主权项

1. A method for wireless communications comprising:
receiving, by a subscriber station from a base station, spatial mode scheduling information regarding an interferer to the subscriber station; performing a channel estimation on a received signal received by the subscriber station, the received signal including an interference signal from the interferer in accordance with the spatial mode scheduling information; deriving a spatial whitening filter in accordance with the interference signal; applying the spatial whitening filter to the received signal; determining an expected rate in accordance with the spatial whitening filter applied-received signal for each of a plurality of interfering spatial modes of the interferer; identifying, in accordance with each respective expected rate, a preferred spatial mode for each of the plurality of interfering spatial modes of the interferer, for subsequent transmissions to the subscriber station; and transmitting, from the subscriber station to the base station, a spatial mode table comprising each respective preferred spatial mode for each of the plurality of interfering spatial modes of the interferer.