Downlink PDSCH transmission mode selection and switching algorithm for LTE

A base station comprising:

• a processor;
• a memory having stored therein a scheduler;
• a utility which when executed by the processor, provides the functions of:
• receiving a request from a wireless device for downlink physical shared channel (PDSCH) downlink transmission via a particular transmission mode and a specific rank that represents a first pairing;
• retrieving one or more of:
• (a) historical Hybrid Automatic Repeat Request (HARQ) feedback information corresponding to said particular transmission mode and rank;
• (b) Channel Quality Indicators (CQIs) corresponding to one or more layers of the precoder corresponding to the specific rank requested;
• (c) a Precoder Matrix Index (PMI) report that provides a best precoder corresponding to said particular transmission mode and said specific rank;
• and (d) a rank indicator (RI) report;
• obtaining an estimation of a first HARQ error adjusted throughput associated with said particular transmission mode and said specific rank requested by said wireless device;
• providing estimates of HARQ error adjusted throughput corresponding to other distinct pairings of transmission mode and rank;
• comparing said estimation of said first HARQ error adjusted throughput with said estimates of HARQ error adjusted throughput;
• in response to said comparing, selecting a best pairing of transmission mode and rank with a higher HARQ error adjusted throughput for transmission service for said wireless device;
• and
• in response to the selection, periodically switching from the selected pairing of transmission mode and rank to other pairings of other transmission modes and rank to check if conditions have adequately improved to warrant transmission at a different pairing of transmission mode and rank.

An Evolved Universal Terrestrial Radio Access Network Node B (eNodeB) utilized within a Long Term Evolution (LTE)-based wireless communication system, the eNodeB comprising:

• a processor;
• one or more wireless transmitter/receiver devices (transceivers) communicatively coupled to the processor and which enables communicating with one or more wireless communication devices;
• a memory having stored therein a scheduler;
• a utility which when executed by the processor, provides the functions of:
• receiving a request from a wireless device for downlink physical shared channel (PDSCH) downlink transmission via a particular transmission mode and a specific rank that represents a first pairing;
• retrieving one or more of:
• (a) historical Hybrid Automatic Repeat Request (HARQ) feedback information corresponding to said particular transmission mode and rank;
• (b) Channel Quality Indicators (CQIs) corresponding to one or more layers of the precoder corresponding to the specific rank requested;
• (c) a Precoder Matrix Index (PMI) report that provides a best precoder corresponding to said particular transmission mode and said specific rank;
• and (d) a rank indicator (RI) report;
• obtaining an estimation of a first HARQ error adjusted throughput associated with said particular transmission mode and said specific rank requested by said wireless device;
• providing estimates of HARQ error adjusted throughput corresponding to other distinct pairings of transmission mode and rank;
• comparing said estimation of said first HARQ error adjusted throughput with said estimates of HARQ error adjusted throughput;
• in response to said comparing, selecting a best pairing of transmission mode and rank with a higher HARQ error adjusted throughput for transmission service for said wireless device;
• and
• in response to the selection, periodically switching from the selected pairing of transmission mode and rank to other pairings of other transmission modes and rank to check if conditions have adequately improved to warrant transmission at a different pairing of transmission mode and rank.